Definition Quotes (238 quotes)
… the definition of irrational numbers, on which geometric representations have often had a confusing influence. … I take in my definition a purely formal point of view, calling some given symbols numbers, so that the existence of these numbers is beyond doubt.
(1872). As quoted in Ernst Hairer and Gerhard Wanner, Analysis by Its History (2008), 177.
…the Form or true definition of heat … is in few words as follows: Heat is a motion; expansive, restrained, and acting in its strife upon the smaller particles of bodies. But the expansion is thus modified; while it expands all ways, it has at the same time an inclination upward. And the struggle in the particles is modified also; it is not sluggish, but hurried and with violence.
Novum Organum (1620), Book 2, Aphorism 20. Translated as 'First Vintage Concerning the Form of Heat', The New Organon: Aphorisms Concerning the Interpretation of Nature and the Kingdom of Man), collected in James Spedding, Robert Ellis and Douglas Heath (eds.), The Works of Francis Bacon (1857), Vol. 4, 154-5.
“Bitzer,” said Thomas Gradgrind. “Your definition of a horse.”
“Quadruped. Graminivorous. Forty teeth; namely, twenty-four grinders, four eye-teeth, and twelve incisive. Sheds coat in the Spring; in marshy countries, sheds hoofs, too. Hoofs hard, but requiring to be shod with iron. Age known by marks in mouth.” Thus (and much more) Bitzer.
“Now girl number twenty,” said Mr. Gradgrind. “You know what a horse is.”
“Quadruped. Graminivorous. Forty teeth; namely, twenty-four grinders, four eye-teeth, and twelve incisive. Sheds coat in the Spring; in marshy countries, sheds hoofs, too. Hoofs hard, but requiring to be shod with iron. Age known by marks in mouth.” Thus (and much more) Bitzer.
“Now girl number twenty,” said Mr. Gradgrind. “You know what a horse is.”
Spoken by fictional character Thomas Gringrind in his schoolroom with pupil Bitzer, Hard Times, published in Household Words (1 Apr 1854), Vol. 36, 3.
“When I use a word,” Humpty Dumpty said, in rather a scornful tone, “it means just what I choose it to mean—neither more nor less.”
“The question is,” said Alice, “whether you can make words mean so many different things.”
“The question is,” said Humpty Dumpty, “which is to be master—that's all.”
“The question is,” said Alice, “whether you can make words mean so many different things.”
“The question is,” said Humpty Dumpty, “which is to be master—that's all.”
Through the Looking Glass and What Alice Found There (1871, 1897), 124.
“Wu Li” was more than poetic. It was the best definition of physics that the conference would produce. It caught that certain something, that living quality that we were seeking to express in a book, that thing without which physics becomes sterile. “Wu” can mean either “matter” or “energy.” “Li” is a richly poetic word. It means “universal order” or “universal law.” It also means “organic patterns.” The grain in a panel of wood is Li. The organic pattern on the surface of a leaf is also Li, and so is the texture of a rose petal. In short, Wu Li, the Chinese word for physics, means “patterns of organic energy” (“matter/ energy” [Wu] + “universal order/organic patterns” [Li]). This is remarkable since it reflects a world view which the founders of western science (Galileo and Newton) simply did not comprehend, but toward which virtually every physical theory of import in the twentieth century is pointing!
In The Dancing Wu Li Masters: An Overview of the New Physics (1979), 5.
[Scientists] define these [terms] in tight phrases which convey a meaning only to those who already understand it.
In Science is a Sacred Cow (1950), 31.
[Zoophytes (Protists, or simple life forms) are] the primitive types from which all the organisms of the higher classes had arisen by gradual development.
Entry for Gottfried Reinhold Treviranus in Encyclopedia Britannica (1911), Vol. 27, 255-256.
[Defining Life] An internal principle of action.
Kritik der Urtheilskraft in Werke, IV, 260). In George Henry Lewes, Aristotle (1864), 229.
[Defining Life] The constant uniformity of phenomena under diversity of external influences.
Biologie (1802). As cited in translated form in George Henry Lewes, Physiology of Common Life (1875), Vol. 2, 356.
[Defining Organism] That in which every part is at once means and end.
Kritik der Urtheilskraft in Werke, IV, 260). In George Henry Lewes, Aristotle (1864), 229.
Energie is the operation, efflux or activity of any being: as the light of the Sunne is the energie of the Sunne, and every phantasm of the soul is the energie of the soul.
[The first recorded definition of the term energy in English]
[The first recorded definition of the term energy in English]
In Platonica: A Platonicall Song of the Soul (1642). In this book of poems, More uses the word energie many times, and in the opening section, 'To the Reader'. The definition quoted appears at the end of the book in 'The interpretation of the more unusual names or words that occurre in the foregoing Poems.'
Les principes sont des conventions et des définitions déguisés.
Principles are conventions and definitions in disguise.
Principles are conventions and definitions in disguise.
From La Science et l’Hypothèse (1902), 165. Translation by George Bruce Halsted, Science and Hypothesis (New York, 1905), 100. In Science and Hypothesis (London 1905), 138.
Q: What is the definition of a tachyon?
A: It’s a gluon that’s not completely dry.
A: It’s a gluon that’s not completely dry.
The Word Reason in the English Language has different Significances: sometimes it is taken for true, and clear Principles: Sometimes for clear, and fair deductions from those Principles: and sometimes for Cause, and particularly the final Cause: but the Consideration I shall have of it here, is in a Signification different from all these; and that is, as it stands for a Faculty of Man, That Faculty, whereby Man is supposed to be distinguished from Beasts; and wherein it is evident he much surpasses them.
In 'Of Reason', Essay Concerning Humane Understanding (1690), Book 4, Ch. 17, Sec. 1, 341.
Vacuum voco locum omnem in quo corpora sine resistentia movetur.
Vacuum I call every place in which a body is able to move without resistance.
Vacuum I call every place in which a body is able to move without resistance.
Original Latin from an unpublished line in a manuscript draft of additions and corrections to the second edition of the Principia held by Cambridge University Library, 'Definition II', MS Add 3965 sec 13 [53-94] Draft No. 3 Folio 422r. As quoted and cited in J.E. McGuire, Tradition and Innovation: Newton’s Metaphysics of Nature (1995, 2011), 139. English translation as given in Isaac Asimov and Jason A. Shulman (eds.), Isaac Asimov’s Book of Science and Nature Quotations (1988), 210.
A totally blind process can by definition lead to anything; it can even lead to vision itself.
In Jacques Monod and Austryn Wainhouse (trans.), Chance and Necessity: An Essay on the Natural Philosophy of Modern Biology (1972), 98.
A definition is the enclosing a wilderness of idea within a wall of words.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 221.
A definition of what we mean by “probability”. … The German Dictionary by Jakob and Wilhelm Grimm gives us detailed information: The Latin term “probabilis”, we are told, was at one time translated by “like truth”, or, by “with an appearance of truth” (“mit einem Schein der Wahrheit”). Only since the middle of the seventeenth century has it been rendered by “wahrscheinlich” (lit. truth-resembling).
In Probability, Statistics, and Truth (1939, 2nd. ed., 1957), 2.
A discovery must be, by definition, at variance with existing knowledge. During my lifetime, I made two. Both were rejected offhand by the popes of the field. Had I predicted these discoveries in my applications, and had those authorities been my judges, it is evident what their decisions would have been.
In 'Dionysians and Apollonians', Science (2 Jun 1972), 176, 966. Reprinted in Mary Ritchie Key, The Relationship of Verbal and Nonverbal Communication (1980), 318.
A distinguished writer [Siméon Denis Poisson] has thus stated the fundamental definitions of the science:
“The probability of an event is the reason we have to believe that it has taken place, or that it will take place.”
“The measure of the probability of an event is the ratio of the number of cases favourable to that event, to the total number of cases favourable or contrary, and all equally possible” (equally like to happen).
From these definitions it follows that the word probability, in its mathematical acceptation, has reference to the state of our knowledge of the circumstances under which an event may happen or fail. With the degree of information which we possess concerning the circumstances of an event, the reason we have to think that it will occur, or, to use a single term, our expectation of it, will vary. Probability is expectation founded upon partial knowledge. A perfect acquaintance with all the circumstances affecting the occurrence of an event would change expectation into certainty, and leave neither room nor demand for a theory of probabilities.
“The probability of an event is the reason we have to believe that it has taken place, or that it will take place.”
“The measure of the probability of an event is the ratio of the number of cases favourable to that event, to the total number of cases favourable or contrary, and all equally possible” (equally like to happen).
From these definitions it follows that the word probability, in its mathematical acceptation, has reference to the state of our knowledge of the circumstances under which an event may happen or fail. With the degree of information which we possess concerning the circumstances of an event, the reason we have to think that it will occur, or, to use a single term, our expectation of it, will vary. Probability is expectation founded upon partial knowledge. A perfect acquaintance with all the circumstances affecting the occurrence of an event would change expectation into certainty, and leave neither room nor demand for a theory of probabilities.
An Investigation of the Laws of Thought (1854), 243-244. The Poisson quote is footnoted as from Recherches sur la Probabilité des Jugemens.
A fractal is a mathematical set or concrete object that is irregular or fragmented at all scales.
Cited as from Fractals: Form, Chance, and Dimension (1977), by J.W. Cannon, in review of The Fractal Geometry of Nature (1982) in The American Mathematical Monthly (Nov 1984), 91, No. 9, 594.
A hypothesis may be simply defined as a guess. A scientific hypothesis is an intelligent guess.
In Isaac Asimov’s Book of Science and Nature Quotations (1988), 114.
A mathematician who can only generalise is like a monkey who can only climb UP a tree. ... And a mathematician who can only specialise is like a monkey who can only climb DOWN a tree. In fact neither the up monkey nor the down monkey is a viable creature. A real monkey must find food and escape his enemies and so must be able to incessantly climb up and down. A real mathematician must be able to generalise and specialise. ... There is, I think, a moral for the teacher. A teacher of traditional mathematics is in danger of becoming a down monkey, and a teacher of modern mathematics an up monkey. The down teacher dishing out one routine problem after another may never get off the ground, never attain any general idea. and the up teacher dishing out one definition after the other may never climb down from his verbiage, may never get down to solid ground, to something of tangible interest for his pupils.
From 'A Story With A Moral', Mathematical Gazette (Jun 1973), 57, No. 400, 86-87
A person who is religiously enlightened appears to me to be one who has, to the best of his ability, liberated himself from the fetters of his selfish desires and is preoccupied with thoughts, feelings, and aspirations to which he clings because of their superpersonal value. It seems to me that what is important is the force of this superpersonal content and the depth of the conviction concerning its overpowering meaningfulness, regardless of whether any attempt is made to unite this content with a divine Being, for otherwise it would not be possible to count Buddha and Spinoza as religious personalities. Accordingly, a religious person is devout in the sense that he has no doubt of the significance and loftiness of those superpersonal objects and goals which neither require nor are capable of rational foundation. They exist with the same necessity and matter-of-factness as he himself. In this sense religion is the age-old endeavor of mankind to become clearly and completely conscious of these values and goals and constantly to strengthen and extend their effect. If one conceives of religion and science according to these definitions then a conflict between them appears impossible. For science can only ascertain what is, but not what should be, and outside of its domain value judgments of all kinds remain necessary.
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A plant is a living thing that absorbs in microscopic amounts over its surface what it needs for growth. It spreads therefore an exterior whereas the animal develops, through its mouth, an interior. The definition is vague but it gives the reason why the limb of a tree ends in leaves, not fingers, and it helps to explain how in the long run of evolution a monkey came to sit on the tree and a cow to ruminate in its shade.
Opening of Chapter 1, The Life of Plants (1964, 2002), 1.
A poet is, after all, a sort of scientist, but engaged in a qualitative science in which nothing is measurable. He lives with data that cannot be numbered, and his experiments can be done only once. The information in a poem is, by definition, not reproducible. ... He becomes an equivalent of scientist, in the act of examining and sorting the things popping in [to his head], finding the marks of remote similarity, points of distant relationship, tiny irregularities that indicate that this one is really the same as that one over there only more important. Gauging the fit, he can meticulously place pieces of the universe together, in geometric configurations that are as beautiful and balanced as crystals.
In The Medusa and the Snail: More Notes of a Biology Watcher (1974, 1995), 107.
A right understanding of the words which are names of names, is of great importance in philosophy. The tendency was always strong to believe that whatever receives a name must be an entity or being, having an independent existence of its own; and if no real entity answering to the name could be found, men did not for that reason suppose that none existed, but imagined that it was something peculiarly abstruse and mysterious, too high to be an object of sense. The meaning of all general, and especially of all abstract terms, became in this way enveloped in a mystical haze; and none of these have been more generally misunderstood, or have been a more copious source of futile and bewildering speculation, than some of the words which are names of names. Genus, Species, Universal, were long supposed to be designations of sublime hyperphysical realities; Number, instead of a general name of all numerals, was supposed to be the name, if not of a concrete thing, at least of a single property or attribute.
A footnote by John Stuart Mill, which he added as editor of a new edition of a work by his father, James Mill, Analysis of the Phenomena of the Human Mind (1869), Vol. 2, 5.
A substance that makes you ill if you don’t eat it.
[His definition of a vitamin.]
[His definition of a vitamin.]
Attributed.
A working definition of life, … could [be] in terms of a large molecule made up of carbon compounds that can replicate, or make copies of itself, and metabolize food and energy…: macromolecule, metabolism, replication.
From interview, 'The Seeds of Life', in The Omni Interviews (1984), 4.
According to Democritus, atoms had lost the qualities like colour, taste, etc., they only occupied space, but geometrical assertions about atoms were admissible and required no further analysis. In modern physics, atoms lose this last property, they possess geometrical qualities in no higher degree than colour, taste, etc. The atom of modern physics can only be symbolized by a partial differential equation in an abstract multidimensional space. Only the experiment of an observer forces the atom to indicate a position, a colour and a quantity of heat. All the qualities of the atom of modern physics are derived, it has no immediate and direct physical properties at all, i.e. every type of visual conception we might wish to design is, eo ipso, faulty. An understanding of 'the first order' is, I would almost say by definition, impossible for the world of atoms.
Philosophic Problems of Nuclear Science, trans. F. C. Hayes (1952), 38.
According to Gandhi, the seven sins are wealth without works, pleasure without conscience, knowledge without character, commerce without morality, science without humanity, worship without sacrifice, and politics without principle. Well, Hubert Humphrey may have sinned in the eyes of God, as we all do, but according to those definitions of Gandhi’s, it was Hubert Humphrey without sin.
Eulogy at funeral of Vice President Hubert Humphrey, St. Paul, Minnesota (16 Jan 1978). In Public Papers of the Presidents of the United States: Jimmy Carter (1978), Vol. 1, 82.
And, to prevent mistakes, I must advertize you, that I now mean by elements, as those chymists that speak plainest do by their principles, certain primitive or simple, or perfectly unmingled bodies; which not being made of any other bodies, or of one another, are the ingredients of which all those called perfectly mixt bodies are immediately compounded, and into which they are ultimately resolved: now whether there be any such body to be constantly met with in all, and each, of those that are said to be elemented bodies, is the thing I now question.
The Sceptical Chemist (2nd ed., 1661), Appendix, 354. As given in Henry M. Leicester and Herbert S. Klickstein, A Source Book in Chemistry 1400-1900 (1952), 42.
Any conception which is definitely and completely determined by means of a finite number of specifications, say by assigning a finite number of elements, is a mathematical conception. Mathematics has for its function to develop the consequences involved in the definition of a group of mathematical conceptions. Interdependence and mutual logical consistency among the members of the group are postulated, otherwise the group would either have to be treated as several distinct groups, or would lie beyond the sphere of mathematics.
In 'Mathematics', Encyclopedia Britannica (9th ed.).
As an empiricist I continue to think of the conceptual scheme of science as a tool, ultimately, for predicting future experience in the light of past experience. Physical objects are conceptually imported into the situation as convenient intermediaries—not by definition in terms of experience, but simply as irreducible posits comparable, epistemologically, to the gods of Homer. For my part I do, qua lay physicist, believe in physical objects and not in Homer's gods; and I consider it a scientific error to believe otherwise. But in point of epistemological footing the physical objects and the gods differ only in degree and not in kind. Both sorts of entities enter our conception only as cultural posits. The myth of physical objects is epistemologically superior to most in that it has proved more efficacious than other myths as a device for working a manageable structure into the flux of experience.
From A Logical Point of View (1953), 44. [Note: “qua” means “in the character or role of,” thus “qua lay physicist” means “in the role of lay physicist,” or perhaps even (?) “putting on my lay physicist hat.” —Webmaster]
As Love is too young to know what conscience is, so Truth and Genius are too old to know what definition is.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 221.
As, no matter what cunning system of checks we devise, we must in the end trust some one whom we do not check, but to whom we give unreserved confidence, so there is a point at which the understanding and mental processes must be taken as understood without further question or definition in words. And I should say that this point should be fixed pretty early in the discussion.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 220-221.
Bridges would not be safer if only people who knew the proper definition of a real number were allowed to design them.
In 'Topological Theory of Defects', Review of Modern Physics (Jul 1979), 51, No. 3. 591–648. This is seen widely on the web (? mis-)attributed to H.L. Mencken, for which Webmaster has so far been unable to find any validation whatsoever.
Chance ... must be something more than the name we give to our ignorance.
In Science and Method (1908) translated by Francis Maitland (1914, 2007), 66.
Chemistry is the study of the effects of heat and mixture, with a view of discovering their general and subordinate laws, and of improving the useful arts.
This is an editor’s shorter restatement of the definition given by Black in the first of a series of lectures on chemistry, collected in John Robison (ed.), Lectures on the Elements of Chemistry: Delivered in the University of Edinburgh (1807), Vol. 1, 11, footnote. For the definitions as given by Black, see elsewhere on this web page.
Chemists have made of phlogiston a vague principle which is not at all rigorously defined, and which, in consequence, adapts itself to all explanations in which it is wished it shall enter; sometimes it is free fire, sometimes it is fire combined with the earthy element; sometimes it passes through the pores of vessels, sometimes they are impenetrable to it; it explains both the causticity and non-causticity, transparency and opacity, colours and absence of colours. It is a veritable Proteus which changes its form every instant. It is time to conduct chemistry to a more rigorous mode of reasoning ... to distinguish fact and observation from what is systematic and hypothetical.
'Réflexions sur le phlogistique', Mémoires de l'Académie des Sciences, 1783, 505-38. Reprinted in Oeuvres de Lavoisier (1864), Vol. 2, 640, trans. M. P. Crosland.
Chymistry. … An art whereby sensible bodies contained in vessels … are so changed, by means of certain instruments, and principally fire, that their several powers and virtues are thereby discovered, with a view to philosophy or medicine.
An antiquated definition, as quoted in Samuel Johnson, entry for 'Chymistry' in Dictionary of the English Language (1785). Also in The Quarterly Journal of Science, Literature, and the Arts (1821), 284, wherein a letter writer (only identified as “C”) points out that this definition still appeared in the, then, latest Rev. Mr. Todd’s Edition of Johnson’s Dictionary, and that it showed “very little improvement of scientific words.” The letter included examples of better definitions by Black and by Davy. (See their pages on this website.)
Classes and concepts may, however, also be conceived as real objects, namely classes as “pluralities of things” or as structures consisting of a plurality of things and concepts as the properties and relations of things existing independently of our definitions and constructions. It seems to me that the assumption of such objects is quite as legitimate as the assumption of physical bodies and there is quite as much reason to believe in their existence. They are in the same sense necessary to obtain a satisfactory system of mathematics as physical bodies are necessary for a satisfactory theory of our sense perceptions…
In 'Russell's Mathematical Logic', in P.A. Schilpp (ed.), The Philosophy of Bertrand Russell (1944), Vol. 1, 137.
Culture can be regarded as a constitution of recipes for behavior … which are taught and learned on various levels of awareness; not all of the individuals in any society know all these recipes; and many of the recipes are alternative to one another.
Acknowledging the significance of variation for the culture concept. In The Modal Personality Structure of the Tuscarora Indians As Revealed by the Rorschach Test (1952), 61-62.
Definition of Mathematics.—It has now become apparent that the traditional field of mathematics in the province of discrete and continuous number can only be separated from the general abstract theory of classes and relations by a wavering and indeterminate line. Of course a discussion as to the mere application of a word easily degenerates into the most fruitless logomachy. It is open to any one to use any word in any sense. But on the assumption that “mathematics” is to denote a science well marked out by its subject matter and its methods from other topics of thought, and that at least it is to include all topics habitually assigned to it, there is now no option but to employ “mathematics” in the general sense of the “science concerned with the logical deduction of consequences from the general premisses of all reasoning.”
In article 'Mathematics', Encyclopedia Britannica (1911, 11th ed.), Vol. 17, 880. In the 2006 DVD edition of the encyclopedia, the definition of mathematics is given as “The science of structure, order, and relation that has evolved from elemental practices of counting, measuring, and describing the shapes of objects.” [Premiss is a variant form of “premise”. —Webmaster]
Definitions are a kind of scratching and generally leave a sore place more sore than it was before.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 221.
Descriptive geometry has two objects: the first is to establish methods to represent on drawing paper which has only two dimensions,—namely, length and width,—all solids of nature which have three dimensions,—length, width, and depth,—provided, however, that these solids are capable of rigorous definition.
The second object is to furnish means to recognize accordingly an exact description of the forms of solids and to derive thereby all truths which result from their forms and their respective positions.
The second object is to furnish means to recognize accordingly an exact description of the forms of solids and to derive thereby all truths which result from their forms and their respective positions.
From On the Purpose of Descriptive Geometry as translated by Arnold Emch in David Eugene Smith, A Source Book in Mathematics (1929), 426.
Disease may be defined as “A change produced in living things in consequence of which they are no longer in harmony with their environment.”
In Disease and its Causes (1913), 9.
Engineering is the art or science of making practical.
The Existential Pleasures of Engineering (1976), x.
Engineering is the professional and systematic application of science to the efficient utilization of natural resources to produce wealth.
T. J. Hoover and John Charles Lounsbury (J.C.L.) Fish, The Engineering Profession (1941), 10.
Euclid always contemplates a straight line as drawn between two definite points, and is very careful to mention when it is to be produced beyond this segment. He never thinks of the line as an entity given once for all as a whole. This careful definition and limitation, so as to exclude an infinity not immediately apparent to the senses, was very characteristic of the Greeks in all their many activities. It is enshrined in the difference between Greek architecture and Gothic architecture, and between Greek religion and modern religion. The spire of a Gothic cathedral and the importance of the unbounded straight line in modern Geometry are both emblematic of the transformation of the modern world.
In Introduction to Mathematics (1911), 119.
Every definition implies an axiom, since it asserts the existence of the object defined. The definition then will not be justified, from the purely logical point of view, until we have ‘proved’ that it involves no contradiction either in its terms or with the truths previously admitted.
…...
Exactness cannot be established in the arguments unless it is first introduced into the definitions.
In Science et Méthode, as translated by Francis Maitland, in Science and Method (1914), 123-124.
Experiments on ornamental plants undertaken in previous years had proven that, as a rule, hybrids do not represent the form exactly intermediate between the parental strains. Although the intermediate form of some of the more striking traits, such as those relating to shape and size of leaves, pubescence of individual parts, and so forth, is indeed nearly always seen, in other cases one of the two parental traits is so preponderant that it is difficult or quite impossible, to detect the other in the hybrid. The same is true for Pisum hybrids. Each of the seven hybrid traits either resembles so closely one of the two parental traits that the other escapes detection, or is so similar to it that no certain distinction can be made. This is of great importance to the definition and classification of the forms in which the offspring of hybrids appear. In the following discussion those traits that pass into hybrid association entirely or almost entirely unchanged, thus themselves representing the traits of the hybrid, are termed dominating and those that become latent in the association, recessive. The word 'recessive' was chosen because the traits so designated recede or disappear entirely in the hybrids, but reappear unchanged in their progeny, as will be demonstrated later.
'Experiments on Plant Hybrids' (1865). In Curt Stern and Eva R. Sherwood (eds.), The Origin of Genetics: A Mendel Source Book (1966), 9.
Extinction has only separated groups: it has by no means made them; for if every form which has ever lived on this earth were suddenly to reappear, though it would be quite impossible to give definitions by which each group could be distinguished from other groups, as all would blend together by steps as fine as those between the finest existing varieties, nevertheless a natural classification, or at least a natural arrangement, would be possible.
From On the Origin of Species by Means of Natural Selection; or, The Preservation of Favoured Races in the Struggle for Life (1860), 431.
Following the original proposal of Belinfante, “the writer has in a recent note on the meson theory of nuclear forces” used the word “nuclon” as a common notation for the heavy nuclear constituents, neutrons and protons. In the meantime, however, it has been pointed out to me that, since the root of the word nucleus is “nucle”, the notation “nucleon” would from a philological point of view be more appropriate for this purpose….
In Physical Review (1 Feb 1941), 59, 323. For book using the word “nuclon”, see Frederik Jozef Belinfante, Theory of Heavy Quanta: Proefschrift (1939), 40.
Food may be defined as material which, when taken into the body, serves to either form tissue or yield energy, or both. This definition includes all the ordinary food materials, since they both build tissue and yield energy. It includes sugar and starch, because they yield energy and form fatty tissue. It includes alcohol, because the latter is burned to yield energy, though it does not build tissue. It excludes creatin, creatininin, and other so-called nitrogeneous extractives of meat, and likewise thein or caffein of tea and coffee, because they neither build tissue nor yield energy, although they may, at times, be useful aids to nutrition.
Methods and Results of Investigations on the Chemistry and Economy of Food, Bulletin 21, US Department of Agriculture (1895). Quoted in Ira Wolinsky, Nutrition in Exercise and Sport (1998), 36.
For to define true madness,
What is't but to be nothing else but mad?
What is't but to be nothing else but mad?
Hamlet (1601), II, ii.
From Pythagoras (ca. 550 BC) to Boethius (ca AD 480-524), when pure mathematics consisted of arithmetic and geometry while applied mathematics consisted of music and astronomy, mathematics could be characterized as the deductive study of “such abstractions as quantities and their consequences, namely figures and so forth” (Aquinas ca. 1260). But since the emergence of abstract algebra it has become increasingly difficult to formulate a definition to cover the whole of the rich, complex and expanding domain of mathematics.
In 100 Years of Mathematics: a Personal Viewpoint (1981), 2.
Genius … has been defined as a supreme capacity for taking trouble… It more fitly could be described as a supreme capacity for getting its possessors into trouble of all kinds and keeping them there so long as the genius remains.
In Samuel Butler and Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1913), 174-175.
Genius can only breathe freely in an atmosphere of freedom. Persons of genius are, ex vi termini, more individual than any other people—less capable, consequently, of fitting themselves, without hurtful compression, into any of the small number of moulds which society provides in order to save its members the trouble of forming their own character.
In On Liberty (1859), 116. The Latin expression, “Ex vi terminii,” means “by definition”, though a literal translation is “from the strength of the border.”
Geometrical axioms are neither synthetic a priori conclusions nor experimental facts. They are conventions: our choice, amongst all possible conventions, is guided by experimental facts; but it remains free, and is only limited by the necessity of avoiding all contradiction. ... In other words, axioms of geometry are only definitions in disguise.
That being so what ought one to think of this question: Is the Euclidean Geometry true?
The question is nonsense. One might as well ask whether the metric system is true and the old measures false; whether Cartesian co-ordinates are true and polar co-ordinates false.
That being so what ought one to think of this question: Is the Euclidean Geometry true?
The question is nonsense. One might as well ask whether the metric system is true and the old measures false; whether Cartesian co-ordinates are true and polar co-ordinates false.
In George Edward Martin, The Foundations of Geometry and the Non-Euclidean Plane (1982), 110.
Gyroscope, n.: A wheel or disk mounted to spin rapidly about an axis and also free to rotate about one or both of two axes perpendicular to each other and the axis of spin so that a rotation of one of the two mutually perpendicular axes results from application of torque to the other when the wheel is spinning and so that the entire apparatus offers considerable opposition depending on the angular momentum to any torque that would change the direction of the axis of spin.
Webster's New Collegiate Dictionary (8th Ed., 1973), 513. (Webmaster comments: A definition which is perfectly easy to understand. Right?)
Historically [chemistry] arose from a constellation of interests: the empirically based technologies of early metallurgists, brewers, dyers, tanners, calciners and pharmacists; the speculative Greek philosphers' concern whether brute matter was invariant or transformable; the alchemists' real or symbolic attempts to achieve the transmutation of base metals into gold; and the iatrochemists' interst in the chemistry and pathology of animal and human functions. Partly because of the sheer complexity of chemical phenomena, the absence of criteria and standards of purity, and uncertainty over the definition of elements ... but above all because of the lack of a concept of the gaseous state of matter, chemistry remained a rambling, puzzling and chaotic area of natural philosophy until the middle of the eighteenth century.
The Chemical Tree: A History of Chemistry (2000), xxii.
How can altruism, which by definition reduces personal fitness, possibly evolve by natural selection? The answer is kinship: if the genes causing the altruism are shared by two organisms because of common descent, and if the altruistic act by one organism increases the joint contribution of these genes to the next generation, the propensity to altruism will spread through the gene pool. This occurs even though the altruist makes less of a solitary contribution to the gene pool as the price of its altruistic act.
In Sociobiology (1975), 3-4.
I am an organic chemist, albeit one who adheres to the definition of organic chemistry given by the great Swedish chemist Berzelius, namely, the chemistry of substances found in living matter, and my science is one of the more abstruse insofar as it rests on concepts and employs a jargon neither of which is a part of everyday experience. Nevertheless, organic chemistry deals with matters of truly vital Importance and in some of its aspects with which I myself have been particularly concerned it may prove to hold the keys to Life itself.
In 'Synthesis in the Study of Nucleotides', Nobel Lecture, 11 December 1957. In Nobel Lectures: Chemistry 1942-1962 (1964), 522.
I can’t think of any definition of the words mathematician or scientist that would apply to me. I think of myself as a journalist who knows just enough about mathematics to be able to take low-level math and make it clear and interesting to nonmathematicians. Let me say that I think not knowing too much about a subject is an asset for a journalist, not a liability. The great secret of my column is that I know so little about mathematics that I have to work hard to understand the subject myself. Maybe I can explain things more clearly than a professional mathematician can.
In Scot Morris, 'Interview: Martin Gardner', Omni, 4, No. 4 (Jan 1982), 68.
I feel that to be a director of a laboratory should not be, by definition, a permanent mission. People should have the courage to step down and go back to science. I believe you will never have a good director of a scientific laboratory unless that director knows he is prepared to become a scientist again. … I gave my contribution; I spent five years of my life to work hard for other people’s interest. … It’s time to go back to science again. I have some wonderful ideas, I feel I’m re-born.
From 'Asking Nature', collected in Lewis Wolpert and Alison Richards (eds.), Passionate Minds: The Inner World of Scientists (1997), 202.
I have no patience with attempts to identify science with measurement, which is but one of its tools, or with any definition of the scientist which would exclude a Darwin, a Pasteur or a Kekulé. The scientist is a practical man and his are practical aims. He does not seek the ultimate but the proximate. He does not speak of the last analysis but rather of the next approximation. His are not those beautiful structures so delicately designed that a single flaw may cause the collapse of the whole. The scientist builds slowly and with a gross but solid kind of masonry. If dissatisfied with any of his work, even if it be near the very foundations, he can replace that part without damage to the remainder. On the whole, he is satisfied with his work, for while science may never be wholly right it certainly is never wholly wrong; and it seems to be improving from decade to decade.
The Anatomy of Science (1926), 6-7.
I read somewhere that some people believe that the entire universe is a matrix of living thought. And I said, “Man, if that’s not a definition of God, I don’t know what is.”
Quoted in Kim Lim (ed.), 1,001 Pearls of Spiritual Wisdom: Words to Enrich, Inspire, and Guide Your Life (2014), 33
I submit that the traditional definition of psychiatry, which is still in vogue, places it alongside such things as alchemy and astrology, and commits it to the category of pseudo-science.
In The Myth of Mental Illness: Foundations of a Theory of Personal Conduct (1961), 1.
I use the word “attraction” here in a general sense for any endeavor whatever of bodies to approach one another, whether that endeavor occurs as a result of the action of the bodies either drawn toward one other or acting on one another by means of spirits emitted or whether it arises from the action of aether or of air or of any medium whatsoever—whether corporeal or incorporeal—in any way impelling toward one another the bodies floating therein. I use the word “impulse” in the same general sense, considering in this treatise not the species of forces and their physical qualities but their quantities and mathematical proportions, as I have explained in the definitions.
The Principia: Mathematical Principles of Natural Philosophy (1687), 3rd edition (1726), trans. I. Bernard Cohen and Anne Whitman (1999), Book I, Section II, Scholium, 588.
If a body previously at rest begin to move, we may be certain that this is only in virtue of some extraneous cause acting upon it. This cause, whatever it may be, and which is known to us only by its effects, we call Force. Force then is any cause whatever of motion.
In Thomas Sutton (trans.), The Elements of Statics (1847), Vol. 1, 1. A footnote is added (Appendix, p.63): “Force is very often defined to be ‘any cause which changes tries to change the state of a body’s rest or motion.’”
If any layman were to ask a number of archaeologists to give, on the spur of the moment, a definition of archaeology, I suspect that such a person might find the answers rather confusing. He would, perhaps, sympathize with Socrates who, when he hoped to learn from the poets and artisans something about the arts they practised, was forced to go away with the conviction that, though they might themselves be able to accomplish something, they certainly could give no clear account to others of what they were trying to do.
Opening statement in lecture at Columbia University (8 Jan 1908), 'Archaeology'. Published by the Columbia University Press (1908).
If any philosopher had been asked for a definition of infinity, he might have produced some unintelligible rigmarole, but he would certainly not have been able to give a definition that had any meaning at all.
…...
If E is considered to be a continuously divisible quantity, this distribution is possible in infinitely many ways. We consider, however—this is the most essential point of the whole calculation—E to be composed of a well-defined number of equal parts and use thereto the constant of nature h = 6.55 ×10-27 erg sec. This constant multiplied by the common frequency ν of the resonators gives us the energy element ε in erg, and dividing E by ε we get the number P of energy elements which must be divided over the N resonators.
[Planck’s constant, as introduced in 1900; subsequently written e = hν.]
[Planck’s constant, as introduced in 1900; subsequently written e = hν.]
In 'On the theory of the energy distribution law of the normal spectrum', in D. ter Haar and Stephen G. Brush, trans., Planck’s Original Papers in Quantum Physics (1972), 40.
If it is possible to have a linear unit that depends on no other quantity, it would seem natural to prefer it. Moreover, a mensural unit taken from the earth itself offers another advantage, that of being perfectly analogous to all the real measurements that in ordinary usage are also made upon the earth, such as the distance between two places or the area of some tract, for example. It is far more natural in practice to refer geographical distances to a quadrant of a great circle than to the length of a pendulum.
'Histoire'. Histoire et Memoires de l’Academie Royale des Science de Paris (1788/1791), 9-10. In Charles Coulston Gillispie, Pierre-Simon Laplace, 1749-1827: A Life in Exact Science (2nd Ed., 2000), 151.
If there is something very slightly wrong in our definition of the theories, then the full mathematical rigor may convert these errors into ridiculous conclusions.
Feynman Lectures on Gravitation, edited by Brian Hatfield (2002), 21.
If we can abstract pathogenicity and hygiene from our notion of dirt, we are left with the old definition of dirt as matter out of place. This is a very suggestive approach. It implies two conditions: a set of ordered relations and a contravention of that order. Dirt then, is never a unique, isolated event.
In Purity and Danger: An Analysis of the Concepts of Pollution and Taboo (1966), 35.
If you ask ... the man in the street ... the human significance of mathematics, the answer of the world will be, that mathematics has given mankind a metrical and computatory art essential to the effective conduct of daily life, that mathematics admits of countless applications in engineering and the natural sciences, and finally that mathematics is a most excellent instrumentality for giving mental discipline... [A mathematician will add] that mathematics is the exact science, the science of exact thought or of rigorous thinking.
Address (28 Mar 1912), Michigan School Masters' Club, Ann Arbor, 'The Humanization of the Teaching of Mathematics. Printed in Science (26 Apr 1912). Collected in The Human Worth of Rigorous Thinking: Essays and Addresses (1916), 65-66.
In any broad program of research the key word in regard to any one aspect of the program is relevance. … Probably “conducive to progress toward the main object of a program” is as good a definition as any,
From a statement (21 Nov 1963) to the Select Committee on Government Research of the U.S. House of Representatives. Excerpted in 'Vannevar Bush Speaks', Science (27 Dec 1963), New Series, 142, No. 3600, 1623.
In any conceivable method ever invented by man, an automaton which produces an object by copying a pattern, will go first from the pattern to a description to the object. It first abstracts what the thing is like, and then carries it out. It’s therefore simpler not to extract from a real object its definition, but to start from the definition.
From lecture series on self-replicating machines at the University of Illinois, Lecture 5 (Dec 1949), 'Re-evaluation of the Problems of Complicated Automata—Problems of Hierarchy and Evolution', Theory of Self-Reproducing Automata (1966).
In defining an element let us not take an external boundary, Let us say, e.g., the smallest ponderable quantity of yttrium is an assemblage of ultimate atoms almost infinitely more like each other than they are to the atoms of any other approximating element. It does not necessarily follow that the atoms shall all be absolutely alike among themselves. The atomic weight which we ascribe to yttrium, therefore, merely represents a mean value around which the actual weights of the individual atoms of the “element” range within certain limits. But if my conjecture is tenable, could we separate atom from atom, we should find them varying within narrow limits on each side of the mean.
Address to Annual General Meeting of the Chemical Society (28 Mar 1888), printed in Journal of the Chemical Society (1888), 491.
In despair, I offer your readers their choice of the following definitions of entropy. My authorities are such books and journals as I have by me at the moment.
(a) Entropy is that portion of the intrinsic energy of a system which cannot be converted into work by even a perfect heat engine.—Clausius.
(b) Entropy is that portion of the intrinsic energy which can be converted into work by a perfect engine.—Maxwell, following Tait.
(c) Entropy is that portion of the intrinsic energy which is not converted into work by our imperfect engines.—Swinburne.
(d) Entropy (in a volume of gas) is that which remains constant when heat neither enters nor leaves the gas.—W. Robinson.
(e) Entropy may be called the ‘thermal weight’, temperature being called the ‘thermal height.’—Ibid.
(f) Entropy is one of the factors of heat, temperature being the other.—Engineering.
I set up these bald statement as so many Aunt Sallys, for any one to shy at.
[Lamenting a list of confused interpretations of the meaning of entropy, being hotly debated in journals at the time.]
(a) Entropy is that portion of the intrinsic energy of a system which cannot be converted into work by even a perfect heat engine.—Clausius.
(b) Entropy is that portion of the intrinsic energy which can be converted into work by a perfect engine.—Maxwell, following Tait.
(c) Entropy is that portion of the intrinsic energy which is not converted into work by our imperfect engines.—Swinburne.
(d) Entropy (in a volume of gas) is that which remains constant when heat neither enters nor leaves the gas.—W. Robinson.
(e) Entropy may be called the ‘thermal weight’, temperature being called the ‘thermal height.’—Ibid.
(f) Entropy is one of the factors of heat, temperature being the other.—Engineering.
I set up these bald statement as so many Aunt Sallys, for any one to shy at.
[Lamenting a list of confused interpretations of the meaning of entropy, being hotly debated in journals at the time.]
In The Electrician (9 Jan 1903).
In Geometry, (which is the only Science that it hath pleased God hitherto to bestow on mankind,) men begin at settling the significations of their words; which settling of significations, they call Definitions; and place them in the beginning of their reckoning.
Leviathan (1651), ed. C. B. Macpherson (1968), Part 1, Chapter 4, 105.
In the twenties the late Dr. Glenn Frank, an eminent social scientist, developed a new statement of the scientific code, which has been referred to as the “Five Fingers of the Scientific Method.” It may be outlined as follows: find the facts; filter the facts; focus the facts; face the facts; follow the facts. The facts or truths are found by experimentation; the motivation is material. The facts are filtered by research into the literature; the motivation is material. The facts are focused by the publication of results; again the motivation is material. Thus the first three-fifths of the scientific method have a material motivation. It is about time scientists acknowledge that there is more to the scientific convention than the material aspect. Returning to the fourth and fifth fingers of Dr. Frank's conception of the scientific method, the facts should be faced by the proper interpretation of them for society. In other words, a scientist must assume social responsibility for his discoveries, which means that he must have a moral motivation. Finally, in the fifth definition of the scientific method, the facts are to be followed by their proper application to everyday life in society, which means moral motivation through responsibility to society.
From 'Scientists and Society', American Scientist (Jul 1954), 42, No. 3, 495.
In the world of human thought generally, and in physical science particularly, the most important and fruitful concepts are those to which it is impossible to attach a well-defined meaning.
In M. Dresen, H. A. Kramers: Between Tradition and Revolution (1987), 539. In Magdolna Hargittai, In Our Own Image (2000), 3.
In this manner the whole substance of our geometry is reduced to the definitions and axioms which we employ in our elementary reasonings; and in like manner we reduce the demonstrative truths of any other science to the definitions and axioms which we there employ.
In The Philosophy of the Inductive Sciences: Founded Upon Their History (1840), Vol. 1, 67.
Included in this ‘almost nothing,’ as a kind of geological afterthought of the last few million years, is the first development of self-conscious intelligence on this planet–an odd and unpredictable invention of a little twig on the mammalian evolutionary bush. Any definition of this uniqueness, embedded as it is in our possession of language, must involve our ability to frame the world as stories and to transmit these tales to others. If our propensity to grasps nature as story has distorted our perceptions, I shall accept this limit of mentality upon knowledge, for we receive in trade both the joys of literature and the core of our being.
…...
Induction may be defined, the operation of discovering and proving general propositions.
In A System of Logic, Ratiocinative and Inductive: Being a Connected View of the Principles of Evidence, and the Methods of Scientific Investigation (1843), Vol. 1, 347.
Instinct is defined as the untaught ability to perform actions of all kinds, and more especially such as are necessary or useful to the animal.
The Senses and the Intellect (1855, 1974), p. 246.
It has been proposed (in despair) to define mathematics as “what mathematicians do.” Only such a broad definition, it was felt, would cover all the things that might become embodied in mathematics; for mathematicians today attack many problems not regarded as mathematics in the past, and what they will do in the future there is no saying.
In 'The Extent of Mathematics', Prelude to Mathematics (1955), 11.
It hath been an old remark, that Geometry is an excellent Logic. And it must be owned that when the definitions are clear; when the postulata cannot be refused, nor the axioms denied; when from the distinct contemplation and comparison of figures, their properties are derived, by a perpetual well-connected chain of consequences, the objects being still kept in view, and the attention ever fixed upon them; there is acquired a habit of reasoning, close and exact and methodical; which habit strengthens and sharpens the mind, and being transferred to other subjects is of general use in the inquiry after truth.
In 'The Analyst', in The Works of George Berkeley (1898), Vol. 3, 10.
It is impossible to devise an experiment without a preconceived idea; devising an experiment, we said, is putting a question; we never conceive a question without an idea which invites an answer. I consider it, therefore, an absolute principle that experiments must always be devised in view of a preconceived idea, no matter if the idea be not very clear nor very well defined.
An Introduction to the Study of Experimental Medicine (1865, translation 1927, 1957), 23.
It is natural for man to relate the units of distance by which he travels to the dimensions of the globe that he inhabits. Thus, in moving about the earth, he may know by the simple denomination of distance its proportion to the whole circuit of the earth. This has the further advantage of making nautical and celestial measurements correspond. The navigator often needs to determine, one from the other, the distance he has traversed from the celestial arc lying between the zeniths at his point of departure and at his destination. It is important, therefore, that one of these magnitudes should be the expression of the other, with no difference except in the units. But to that end, the fundamental linear unit must be an aliquot part of the terrestrial meridian. ... Thus, the choice of the metre was reduced to that of the unity of angles.
Lecture at the École Normale to the Year III (Apr 1795), Oeuvres Completes de Laplace (1878-1912), Vol. 14, 141. In Charles Coulston Gillispie, Dictionary of Scientific Biography (1978), Vol. 15, 335.
It is not worth a first class man’s time to express a majority opinion. By definition, there are already enough people to do that.
Quoted in the foreward to A Mathematician's Apology (1941, reprint with Foreward by C.P. Snow 1992), 46.
It is notoriously difficult to define the word living.
Opening sentence in Of Molecules and Men (1966, 2004), 3.
It is of man’s essence to create materially and morally, to fabricate things and to fabricate himself. Homo faber is the definition I propose … Homo faber, Homo sapiens, I pay my respects to both, for they tend to merge.
The Creative Mind (1946), 84-5.
It is really laughable to see what different ideas are prominent in various naturalists’ minds, when they speak of “species”; in some, resemblance is everything and descent of little weight—in some, resemblance seems to go for nothing, and Creation the reigning idea—in some, descent is the key,—in some, sterility an unfailing test, with others it is not worth a farthing. It all comes, I believe, from trying to define the undefinable.
Letter to J. D. Hooker (24 Dec 1856). In Francis Darwin, The Life and Letters of Charles Darwin (1888), 446.
It is usual to say that the two sources of experience are Observation and Experiment. When we merely note and record the phenomena which occur around us in the ordinary course of nature we are said to observe. When we change the course of nature by the intervention of our will and muscular powers, and thus produce unusual combinations and conditions of phenomena, we are said to experiment. [Sir John] Herschel has justly remarked that we might properly call these two modes of experience passive and active observation. In both cases we must certainly employ our senses to observe, and an experiment differs from a mere observation in the fact that we more or less influence the character of the events which we observe. Experiment is thus observation plus alteration of conditions.
Principles of Science: A Treatise on Logic and Scientific Method (1874, 2nd ed., 1913), 400.
It would be well if engineering were less generally thought of, and even defined, as the art of constructing. In a certain important sense it is rather the art of not constructing; or, to define it rudely but not inaptly, it is the art of doing that well with one dollar, which any bungler can do with two after a fashion.
From The Economic Theory of the Location of Railways (1887, 1914), 1.
Language is the principal tool with which we communicate; but when words are used carelessly or mistakenly, what was intended to advance mutual understanding may in fact hinder it; our instrument becomes our burden
Irving M. Copi and Carl Cohen (probably? in their Introduction to Logic), In K. Srinagesh, The Principles of Experimental Research (2006), 15.
Life is a series of definite and successive changes both in structure and in composition, which take place in an individual without destroying its identity.
In Problems of Life and Mind: Second Series: the Physical Basis of Mind (1891), 32.
Life is the twofold internal movement of composition and decomposition at once general and continuous.
In The American Journal of the Medical Sciences (1858), 152.
Logic issues in tautologies, mathematics in identities, philosophy in definitions; all trivial, but all part of the vital work of clarifying and organising our thought.
'Last Papers: Philosophy' (1929), in The Foundations of Mathematics and Other Logical Essays (1931), 264.
MAGNET, n. Something acted upon by magnetism.
MAGNETISM, n. Something acting upon a magnet.
The two definitions immediately foregoing are condensed from the works of one thousand eminent scientists, who have illuminated the subject with a great white light, to the inexpressible advancement of human knowledge.
MAGNETISM, n. Something acting upon a magnet.
The two definitions immediately foregoing are condensed from the works of one thousand eminent scientists, who have illuminated the subject with a great white light, to the inexpressible advancement of human knowledge.
The Collected Works of Ambrose Bierce (1911), Vol. 7, The Devil's Dictionary, 208.
Man is but a perambulating tool-box and workshop or office, fashioned for itself by a piece of very clever slime, as the result of long experience. ... Hence we speak of man's body as his “trunk.”
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 18.
Mankind is a science that defies definitions.
In James Wood, Dictionary of Quotations from Ancient and Modern, English and Foreign Sources (1893), 267:30.
Many errors, of a truth, consist merely in the application of the wrong names of things. For if a man says that the lines which are drawn from the centre of the circle to the circumference are not equal, he understands by the circle, at all events for the time, something else than mathematicians understand by it.
In 'Prop. 47: The human mind possesses an adequate knowledge of the eternal and infinite essence of God', Ethic, translated by William Hale White (1883), 93-94. Collected in The English and Foreign Philosophical Library, Vol. 21.
Mathematical reasoning is deductive in the sense that it is based upon definitions which, as far as the validity of the reasoning is concerned (apart from any existential import), needs only the test of self-consistency. Thus no external verification of definitions is required in mathematics, as long as it is considered merely as mathematics.
In Universal Algebra (1898), Preface, vi.
Mathematics gives the young man a clear idea of demonstration and habituates him to form long trains of thought and reasoning methodically connected and sustained by the final certainty of the result; and it has the further advantage, from a purely moral point of view, of inspiring an absolute and fanatical respect for truth. In addition to all this, mathematics, and chiefly algebra and infinitesimal calculus, excite to a high degree the conception of the signs and symbols—necessary instruments to extend the power and reach of the human mind by summarizing an aggregate of relations in a condensed form and in a kind of mechanical way. These auxiliaries are of special value in mathematics because they are there adequate to their definitions, a characteristic which they do not possess to the same degree in the physical and mathematical [natural?] sciences.
There are, in fact, a mass of mental and moral faculties that can be put in full play only by instruction in mathematics; and they would be made still more available if the teaching was directed so as to leave free play to the personal work of the student.
There are, in fact, a mass of mental and moral faculties that can be put in full play only by instruction in mathematics; and they would be made still more available if the teaching was directed so as to leave free play to the personal work of the student.
In 'Science as an Instrument of Education', Popular Science Monthly (1897), 253.
Mathematics is a public activity. It occurs in a social context and has social consequences. Posing a problem, formulating a definition, proving a theorem are none of them private acts. They are all part of that larger social process we call science.
In 'Mathematics as an Objective Science', The American Mathematical Monthly (Aug-Sep 1979), 86, No. 7, 542. Reprinted in The Mathematical Intelligencer (1983), 5, No. 3.
Mathematics is a study which, when we start from its most familiar portions, may be pursued in either of two opposite directions. The more familiar direction is constructive, towards gradually increasing complexity: from integers to fractions, real numbers, complex numbers; from addition and multiplication to differentiation and integration, and on to higher mathematics. The other direction, which is less familiar, proceeds, by analysing, to greater and greater abstractness and logical simplicity; instead of asking what can be defined and deduced from what is assumed to begin with, we ask instead what more general ideas and principles can be found, in terms of which what was our starting-point can be defined or deduced. It is the fact of pursuing this opposite direction that characterises mathematical philosophy as opposed to ordinary mathematics.
In Introduction to Mathematical Philosophy (1920), 1.
Mathematics is an experimental science, and definitions do not come first, but later on.
In 'On Operators in Physical Mathematics, part II', Proceedings of the Royal Society of London (15 Jun 1893), 54, 121.
Mathematics is not a book confined within a cover and bound between brazen clasps, whose contents it needs only patience to ransack; it is not a mine, whose treasures may take long to reduce into possession, but which fill only a limited number of veins and lodes; it is not a soil, whose fertility can be exhausted by the yield of successive harvests; it is not a continent or an ocean, whose area can be mapped out and its contour defined: it is limitless as that space which it finds too narrow for its aspirations; its possibilities are as infinite as the worlds which are forever crowding in and multiplying upon the astronomer’s gaze; it is as incapable of being restricted within assigned boundaries or being reduced to definitions of permanent validity, as the consciousness of life, which seems to slumber in each monad, in every atom of matter, in each leaf and bud cell, and is forever ready to burst forth into new forms of vegetable and animal existence.
From Commemoration Day Address (22 Feb 1877) at Johns Hopkins University, Baltimore, collected in The Collected Mathematical Papers: (1870-1883) (1909), 77-78.
Mathematics is perfectly free in its development and is subject only to the obvious consideration, that its concepts must be free from contradictions in themselves, as well as definitely and orderly related by means of definitions to the previously existing and established concepts.
In Grundlagen einer allgemeinen Manigfaltigkeitslehre (1883), Sect. 8.
Mathematics is that form of intelligence in which we bring the objects of the phenomenal world under the control of the conception of quantity.
Offered as a provision definition, in 'The Departments of Mathematics, and their Mutual Relations', Journal of Speculative Philosophy (Apr 1871), 5, No. 2, 164.
Mathematics is the science which draws necessary conclusions.
First line of Linear Associative Algebra: read before the National Academy of Sciences, Washington City (1870), 2.
Mathematics, once fairly established on the foundation of a few axioms and definitions, as upon a rock, has grown from age to age, so as to become the most solid fabric that human reason can boast.
In Essays on the Intellectual Powers of Man, 4th. Ed., 461.
Matter, though divisible in an extreme degree, is nevertheless not infinitely divisible. That is, there must be some point beyond which we cannot go in the division of matter. ... I have chosen the word “atom” to signify these ultimate particles.
Dalton's Manuscript Notes, Royal Institution Lecture 18 (30 Jan 1810). In Ida Freund, The Study of Chemical Composition: An Account of its Method and Historical Development (1910), 288.
Medicine has been defined to be the art or science of amusing a sick man with frivolous speculations about his disorder, and of tampering ingeniously, till nature either kills or cures him.
In Tryon Edwards (ed.), A Dictionary of Thoughts (1908), 339.
My definition of an educated man is the fellow who knows the right thing to do at the time it has to be done. You can be sincere and still be stupid.
My definition of science is … somewhat as follows: Science is an interconnected series of concepts and conceptual schemes that have developed as a result of experimentation and observation and are fruitful of further experimentation and observations. In this definition the emphasis is on the word “fruitful.”
In Science and Common Sense (1951), 25.
My Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments: In order to which, I shall premise the following Definitions and Axioms.
Opticks (1704), Book 1, Part 1, Introduction, 1.
My visceral perception of brotherhood harmonizes with our best modern biological knowledge ... Many people think (or fear) that equality of human races represents a hope of liberal sentimentality probably squashed by the hard realities of history. They are wrong. This essay can be summarized in a single phrase, a motto if you will: Human equality is a contingent fact of history. Equality is not true by definition; it is neither an ethical principle (though equal treatment may be) nor a statement about norms of social action. It just worked out that way. A hundred different and plausible scenarios for human history would have yielded other results (and moral dilemmas of enormous magnitude). They didn’t happen.
…...
Ninety-nine [students] out of a hundred are automata, careful to walk in prescribed paths, careful to follow the prescribed custom. This is not an accident but the result of substantial education, which, scientifically defined, is the subsumption of the individual.
As quoted in various 21st century books, each time cited only as from the The Philosophy of Education (1906), with no page number. For example, in John Taylor Gatto, A Different Kind of Teacher: Solving the Crisis of American Schooling (2000), 61. Note: Webmaster is suspicious of the attribution of this quote. The Library of Congress lists no such title by Harris in 1906. The LOC does catalog this title by Harris for 1893, which is a 9-page pamphlet printing the text of a series of five lectures. These lectures do not contain this quote. William Torrey Harris was editor of the International Education Series of books, of which Vol. 1 was the translation by Anna Callender Bracket of The Philosophy of Education by Johann Karl Friedrich Rosenkranz (2nd ed. rev. 1886). The translation was previously published in The Journal of Speculative Philosophy (1872, -73, -74), Vols vi-viii. Webmaster does not find the quote in that book, either. Webmaster has so far been unable to verify this quote, in these words, or even find the quote in any 19th or 20th century publication (which causes more suspicion). If you have access to the primary source for this quote, please contact Webmaster.
No man, not even a doctor, ever gives any other definition of what a nurse should be than this—“devoted and obedient.” This definition would do just as well for a porter. It might even do for a horse. It would not do for a policeman.
Notes on Nursing: what it is and what it is not (1860), 200.
Nowhere is water so beautiful as in the desert for nowhere else is it so scarce. By definition. Water, like a human being or a tree or a bird or a song gains value by rarity, singularity, isolation. In a humid climate water is common. In the desert each drop is precious.
Essay in Desert Images, collected in Beyond the Wall: Essays from the Outside (1984), 82.
Objections … inspired Kronecker and others to attack Weierstrass’ “sequential” definition of irrationals. Nevertheless, right or wrong, Weierstrass and his school made the theory work. The most useful results they obtained have not yet been questioned, at least on the ground of their great utility in mathematical analysis and its implications, by any competent judge in his right mind. This does not mean that objections cannot be well taken: it merely calls attention to the fact that in mathematics, as in everything else, this earth is not yet to be confused with the Kingdom of Heaven, that perfection is a chimaera, and that, in the words of Crelle, we can only hope for closer and closer approximations to mathematical truth—whatever that may be, if anything—precisely as in the Weierstrassian theory of convergent sequences of rationals defining irrationals.
In Men of Mathematics (1937), 431-432.
Of the many definitions of poetry, the simplest is still the best: “memorable speech.”
From 'The Poet's Tongue' (1935), Introduction, collected in Edward Mendelson (ed.), The Complete Works of W.H. Auden: Prose and Travel Books in Prose and Verse: 1926-1938 (1996), Vol. 1.
One can ask: “If I crystallize a virus to obtain a crystal consisting of the molecules that make up the virus, are those molecules lifeless or not?” … The properties of living organisms are those of aggregates of molecules. It’s very difficult to draw a line between molecules that are lifeless and molecules that are not lifeless.
From interview with Neil A. Campbell, in 'Crossing the Boundaries of Science', BioScience (Dec 1986), 36, No. 11, 738.
One cannot explain words without making incursions into the sciences themselves, as is evident from dictionaries; and, conversely, one cannot present a science without at the same time defining its terms.
'Of the Division of the Sciences' (1765), Book 4, Chap. 21, in New Essays on Human Understanding, trans. and ed. Peter Remnal (1981), 522.
One definition of man is “an intelligence served by organs.”
From 'Works and Days' in Society and Solitude (1870). Collected in Emerson's Complete Works (1883), Vol. 7, 151.
Perhaps the least inadequate description of the general scope of modern Pure Mathematics—I will not call it a definition—would be to say that it deals with form, in a very general sense of the term; this would include algebraic form, functional relationship, the relations of order in any ordered set of entities such as numbers, and the analysis of the peculiarities of form of groups of operations.
In Presidential Address British Association for the Advancement of Science, Sheffield, Section A,
Nature (1 Sep 1910), 84, 287.
Physics inquires whether the world is eternal, or perpetual, or had a beginning and will have an end in time, or whether none of these alternatives is accurate.
In The Metalogicon of John of Salisbury: A Twelfth-Century Defense of the Verbal and Logical Arts of the Trivium, Book 2, Chap. 12, as translated by Daniel D. McGarry (1955, 2009), 103. The translator footnotes “eternal” as “without beginning or end” and “perpetual” as “having a beginning, but without end.” The context is describing “physics” as one of the three fields of philosophy (literally, faculties): natural, moral and rational—translated as Physics, Ethics, Logic.
Physio-philosophy has to show how, and in accordance indeed with what laws, the Material took its origin; and, therefore, how something derived its existence from nothing. It has to portray the first periods of the world's development from nothing; how the elements and heavenly bodies originated; in what method by self-evolution into higher and manifold forms, they separated into minerals, became finally organic, and in Man attained self-consciousness.
In Lorenz Oken, trans. by Alfred Tulk, Elements of Physiophilosophy (1847), 1.
Probability is expectation founded upon partial knowledge.
An Investigation of the Laws of Thought (1854), 244. This is part of a longer quote, which begins, “A distinguished writer…”, on the George Boole Quotes page of this website.
Pure mathematics consists entirely of such asseverations as that, if such and such is a proposition is true of anything, then such and such another propositions is true of that thing. It is essential not to discuss whether the first proposition is really true, and not to mention what the anything is of which it is supposed to be true. Both these points would belong to applied mathematics. … If our hypothesis is about anything and not about some one or more particular things, then our deductions constitute mathematics. Thus mathematics may be defined as the the subject in which we never know what we are talking about, not whether what we are saying is true. People who have been puzzled by the beginnings of mathematics will, I hope, find comfort in this definition, and will probably agree that it is accurate.
In 'Recent Work on the Principles of Mathematics', International Monthly (1901), 4, 84.
Pure Mathematics is the class of all propositions of the form “p implies q,” where p and q are propositions containing one or more variables, the same in the two propositions, and neither p nor q contains any constants except logical constants. And logical constants are all notions definable in terms of the following: Implication, the relation of a term to a class of which it is a member, the notion of such that, the notion of relation, and such further notions as may be involved in the general notion of propositions of the above form. In addition to these, mathematics uses a notion which is not a constituent of the propositions which it considers, namely the notion of truth.
In 'Definition of Pure Mathematics', Principles of Mathematics (1903), 3.
Quantity is that which is operated with according to fixed mutually consistent laws. Both operator and operand must derive their meaning from the laws of operation. In the case of ordinary algebra these are the three laws already indicated [the commutative, associative, and distributive laws], in the algebra of quaternions the same save the law of commutation for multiplication and division, and so on. It may be questioned whether this definition is sufficient, and it may be objected that it is vague; but the reader will do well to reflect that any definition must include the linear algebras of Peirce, the algebra of logic, and others that may be easily imagined, although they have not yet been developed. This general definition of quantity enables us to see how operators may be treated as quantities, and thus to understand the rationale of the so called symbolical methods.
In 'Mathematics', Encyclopedia Britannica (9th ed.).
Read, and found correct.
Written, with Einstein’s signature, below this statement written by an admirer: “A Short Definition of Relativity: There is no hitching post in the Universe—as far as we know.”
Written, with Einstein’s signature, below this statement written by an admirer: “A Short Definition of Relativity: There is no hitching post in the Universe—as far as we know.”
As described in Ronald William Clark, Einstein: The Life and Times (1995), 248-249.
Real science exists, then, only from the moment when a phenomenon is accurately defined as to its nature and rigorously determined in relation to its material conditions, that is, when its law is known. Before that, we have only groping and empiricism.
From An Introduction to the Study of Experimental Medicine (1865), as translated by Henry Copley Greene (reprint 1999), 74.
Research is an effort of the mind to comprehend relationships no one has previously known; and it is practical as well as theoretical.
Shown as a slogan of Bell Telephone Laboratories in a Bell Telephone System advertisement, 'The Search That Never Ends', placed, for example, in Life Magazine (17 Jan 1944), 33.
Science can be defined as “the observation, identification, description, experimental investigation and theoretical explanation of natural phenomena.”
In Bernice Zeldin Schacter, Issues and Dilemmas of Biotechnology: A Reference Guide (1999), 1, citing the American Heritage Dictionary, 2nd College Edition.
Science has a simple faith, which transcends utility. Nearly all men of science, all men of learning for that matter, and men of simple ways too, have it in some form and in some degree. It is the faith that it is the privilege of man to learn to understand, and that this is his mission. If we abandon that mission under stress we shall abandon it forever, for stress will not cease. Knowledge for the sake of understanding, not merely to prevail, that is the essence of our being. None can define its limits, or set its ultimate boundaries.
Science is Not Enough (1967), 191.
Science I have defined as a series of concepts or conceptual schemes arising out of experiment and observation and leading to new experiments and new observations. From the experimental work and careful observations of nature come the scientific facts that are tied together by the concepts and conceptual schemes of modern science.
In 'Introduction', James Bryant Conant and Leonard K. Nash, Harvard Case Histories in Experimental Science (1957), x.
Science is, according to Mach, nothing but the comparison and orderly arrangement of factually given contents of our consciousness, in accord with certain gradually acquired points of view and methods. Therefore, physics and psychology differ from each other not so much in the subject matter, but rather only in the points of view of the arrangement and connection of the various topics.
Translation from obituary, 'Ernst Mach', Physikalische Zeitschrift (1 Apr 1916), 102. From the original German text: “Nach Mach ist Wissenschaft nichts anderes, als Vergleichung und Ordnung der uns tatsächlich gegebenen Bewußtseinsinhalte nach gewissen, von uns allmählich ertasteten Gesichtspunkten und Methoden. Physik und Psychologie unterscheiden sich also voneinander nicht in dem Gegenstände, sondern nur in den Gesichtspunkten der Anordnung und Verknüpfung des Stoffes.”
Science recognizes no personal powers in the universe responsive to the prayers and needs of men. Belief in mysterious powers which constitutes, according to our definition, the conceptual aspect of religion is usually an animistic belief in personal powers. Science in effect denies the existence of spiritual beings which religion affirms.
Religion in Human Affairs (1929), 470.
Science, in the immediate, produces knowledge and, indirectly, means of action. It leads to methodical action if definite goals are set up in advance. For the function of setting up goals and passing statements of value transcends its domain. While it is true that science, to the extent of its grasp of causative connections, may reach important conclusions as to the compatibility and incompatibility of goals and evaluations, the independent and fundamental definitions regarding goals and values remain beyond science’s reach.
…...
Scientific method is often defined as if it were a set procedure, to be learned, like a recipe, as if anyone could like a recipe, as if anyone could become a scientist simply by learning the method. This is as absurd ... [so I shall not] discuss scientific method, but rather the methods of scientists. We proceed by common sense and ingenuity. There are no rules, only the principles of integrity and objectivity, with a complete rejection of all authority except that of fact.
In Science in the Making (1957), 8.
Scientific Terminology [is] the Scylla's cave which men of science are preparing for themselves to be able to pounce out upon us from it, and into which we cannot penetrate.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 218.
Should a scientist consider possible ramifications of his research and their effects on society,…? Answer: I think it is impossible for anybody, scientist or not, to foresee the ramifications. We might say that that is a definition of basic science. Vide Einstein’s discovery of 1905 of the equivalence of mass and energy and the development of atomic weaponry. … CONSIDER RAMIFICATIONS? IMPOSSIBLE.
In 'Homo Scientificus According to Beckett," collected in William Beranek, Jr. (ed.)Science, Scientists, and Society, (1972), 135. Excerpted in Ann E. Kammer, Science, Sex, and Society (1979), 277.
Since the Universe is defined as including all that exists, it is useless to ask what lies beyond it.
Epigraph in Isaac Asimov’s Book of Science and Nature Quotations (1988), 328.
Sometime in my early teens, I started feeling an inner urgency, ups and downs of excitement and frustration, caused by such unlikely occupations as reading Granville’s course of calculus ... I found this book in the attic of a friend’s apartment. Among other standard stuff, it contained the notorious epsilon-delta definition of continuous functions. After struggling with this definition for some time (it was the hot Crimean summer, and I was sitting in the shadow of a dusty apple tree), I got so angry that I dug a shallow grave for the book between the roots, buried it there, and left in disdain. Rain started in an hour. I ran back to the tree and exhumed the poor thing. Thus, I discovered that I loved it, regardless.
'Mathematics as Profession and vocation', in V. Arnold et al. (eds.), Mathematics: Frontiers and Perspectives (2000), 153. Reprinted in Mathematics as Metaphor: Selected Essays of Yuri I. Manin (2007), 79.
Statistician: A man who believes figures don’t lie but admits that, under analysis some of them won’t stand up either.
In Esar’s Comic Dictionary (1943, 4th ed. 1983), 568.
Statistics: The only science that enables different experts using the same figures to draw different conclusions.
In Esar’s Comic Dictionary (1943, 4th ed. 1983), 569.
Statistics: The science of producing unreliable facts from reliable figures.
In Esar’s Comic Dictionary (1943, 4th ed. 1983), 568.
Stay your rude steps, or e’er your feet invade
The Muses’ haunts,ye sons of War and Trade!
Nor you, ye legion fiends of Church and Law,
Pollute these pages with unhallow’d paw!
Debased, corrupted, grovelling, and confin’d,
No definitions touch your senseless mind;
To you no Postulates prefer their claim,
No ardent Axioms your dull souls inflame;
For you no Tangents touch, no Angles meet,
No Circles join in osculation sweet!
The Muses’ haunts,ye sons of War and Trade!
Nor you, ye legion fiends of Church and Law,
Pollute these pages with unhallow’d paw!
Debased, corrupted, grovelling, and confin’d,
No definitions touch your senseless mind;
To you no Postulates prefer their claim,
No ardent Axioms your dull souls inflame;
For you no Tangents touch, no Angles meet,
No Circles join in osculation sweet!
From poem, with co-authors John Hookham Frere, George Canning and George Ellis, The Loves of the Triangles: A Mathematical and Philosophical Poem, Canto I, collected in Poetry of the Anti-Jacobin (1854), 124.
Strictly speaking, it is really scandalous that science has not yet clarified the nature of number. It might be excusable that there is still no generally accepted definition of number, if at least there were general agreement on the matter itself. However, science has not even decided on whether number is an assemblage of things, or a figure drawn on the blackboard by the hand of man; whether it is something psychical, about whose generation psychology must give information, or whether it is a logical structure; whether it is created and can vanish, or whether it is eternal. It is not known whether the propositions of arithmetic deal with those structures composed of calcium carbonate [chalk] or with non-physical entities. There is as little agreement in this matter as there is regarding the meaning of the word “equal” and the equality sign. Therefore, science does not know the thought content which is attached to its propositions; it does not know what it deals with; it is completely in the dark regarding their proper nature. Isn’t this scandalous?
From opening paragraph of 'Vorwort', Über die Zahlen des Herrn H. Schubert (1899), iii. ('Foreword', On the Numbers of Mr. H. Schubert). Translated by Theodore J. Benac in Friedrich Waismann, Introduction to Mathematical Thinking: The Formation of Concepts in Modern Mathematics (1959, 2003), 107. Webmaster added “[chalk]”.
Superstition may be defined as constructive religion which has grown incongruous with intelligence.
In 'Science and Man', Fragments of Science (1879), Vol. 2, 370.
Suppose we loosely define a religion as any discipline whose foundations rest on an element of faith, irrespective of any element of reason which may be present. Quantum mechanics for example would be a religion under this definition. But mathematics would hold the unique position of being the only branch of theology possessing a rigorous demonstration of the fact that it should be so classified.
Concluding remark in 'Consistency and Completeness—A Résumé', The American Mathematical Monthly (May 1956), 63, No.5, 305.
Technology is the science of arranging life so that one need not experience it.
…...
That there is no such thing as the scientific method, one might easily discover by asking several scientists to define it. One would find, I am sure, that no two of them would exactly agree. Indeed, no two scientists work and think in just the same ways.
In Science in the Making (1957), 8-9.
That which can affect our senses in any manner whatever, is termed matter.
Opening sentence of English edition, Siméon-Denis Poisson and Henry Hickman Harte (trans.), 'Introduction', A Treatise of Mechanics (1842), Vol. 1, 1. From the original French, “La matière est tout ce qui peut affecter nos sens d’une manière quelconque.”, in 'Introduction', Traité de Mécanique (2nd Ed., 1833), Vol. 1, 1. This definition does not appear in the 1st ed. (1811).
The apodictic quality of mathematical thought, the certainty and correctness of its conclusions, are due, not to a special mode of ratiocination, but to the character of the concepts with which it deals. What is that distinctive characteristic? I answer: precision, sharpness, completeness,* of definition. But how comes your mathematician by such completeness? There is no mysterious trick involved; some ideas admit of such precision, others do not; and the mathematician is one who deals with those that do.
In 'The Universe and Beyond', Hibbert Journal (1904-1905), 3, 309. An editorial footnote indicates “precision, sharpness, completeness” — i.e., in terms of the absolutely clear and indefinable.
The cause, then, philosophically speaking, is the sum total of the conditions, positive and negative, taken together; the whole of the contingencies of every description, which being realized, the consequent invariably follows.
A System of Logic, Ratiocinative and Inductive (1858), 200.
The chemist studies the effects produced by heat and by mixture, in all bodies, or mixtures of bodies, natural or artificial, and studies them with a view to the improvement of arts, and the knowledge of nature.
Restating his own definition in fewer words, from the first of a series of lectures on chemistry, collected in John Robison (ed.), Lectures on the Elements of Chemistry: Delivered in the University of Edinburgh (1807), Vol. 1, 11.
The definition of a good mathematical problem is the mathematics it generates rather than the problem itself.
From interview for PBS website on the NOVA program, 'The Proof'.
The dimmed outlines of phenomenal things all merge into one another unless we put on the focusing-glass of theory, and screw it up sometimes to one pitch of definition and sometimes to another, so as to see down into different depths through the great millstone of the world.
Are There Real Analogies in Nature?' (Feb 1856). Quoted in Lewis Campbell and William GarnettThe Life of James Clerk Maxwell (1882), 237.
The engineer is concerned to travel from the abstract to the concrete. He begins with an idea and ends with an object. He journeys from theory to practice. The scientist’s job is the precise opposite. He explores nature with his telescopes or microscopes, or much more sophisticated techniques, and feeds into a computer what he finds or sees in an attempt to define mathematically its significance and relationships. He travels from the real to the symbolic, from the concrete to the abstract. The scientist and the engineer are the mirror image of each other.
In The Development of Design (1981), 19-20.
The errors of definitions multiply themselves according as the reckoning proceeds; and lead men into absurdities, which at last they see but cannot avoid, without reckoning anew from the beginning.
In Thomas Hobbes and William Molesworth (ed.) Leviathan: Or the Matter, Form and Power of a Commonwealth Ecclesiastical and Civil (1839), Vol. 3, 24.
The experiment serves two purposes, often independent one from the other: it allows the observation of new facts, hitherto either unsuspected, or not yet well defined; and it determines whether a working hypothesis fits the world of observable facts.
In Louis Pasteur, Free Lance of Science (1960), 362.
The extensive literature addressed to the definition or characterization of science is filled with inconsistent points of view and demonstrates that an adequate definition is not easy to attain. Part of the difficulty arises from the fact that the meaning of science is not fixed, but is dynamic. As science has evolved, so has its meaning. It takes on a new meaning and significance with successive ages.
Opening statement on 'The Meaning of “Science”', in Scientific Method: Optimizing Applied Research Decisions (1962), 1.
The fundamental biological variant is DNA. That is why Mendel's definition of the gene as the unvarying bearer of hereditary traits, its chemical identification by Avery (confirmed by Hershey), and the elucidation by Watson and Crick of the structural basis of its replicative invariance, are without any doubt the most important discoveries ever made in biology. To this must be added the theory of natural selection, whose certainty and full significance were established only by those later theories.
In Jacques Monod and Austryn Wainhouse (trans.), Chance and Necessity: An Essay on the Natural Philosophy of Modern Biology (1971), 104.
The Hypochondriake disease..[is] a drie and hote distemperature of Mesenterium, the liver and spleene.
Earliest citation in the etymology of the word hypochondriac given in the Oxford English Dictionary.
Earliest citation in the etymology of the word hypochondriac given in the Oxford English Dictionary.
Discours de la conservation de la veue; des maladies mélancholiques, des catarrhes, et de la vieillese (1594). In Richard Surphlet (trans.) A Discourse of the Preservation of the Sight: of Melancholike Diseases; of Rheumes, and of Old Age (1599), 125.
The institutional goal of science is the extension of certified knowledge. The technical methods employed toward this end provide the relevant definition of knowledge: empirically confirmed and logically consistent predictions. The institutional imperatives (mores) derive from the goal and the methods. The entire structure of technical and moral norms implements the final objective. The technical norm of empirical evidence, adequate, valid and reliable, is a prerequisite for sustained true prediction; the technical norm of logical consistency, a prerequisite for systematic and valid prediction. The mores of science possess a methodologic rationale but they are binding, not only because they are procedurally efficient, but because they are believed right and good. They are moral as well as technical prescriptions. Four sets of institutional imperatives–universalism, communism, disinterestedness, organized scepticism–comprise the ethos of modern science.
Social Theory and Social Structure (1957), 552-3.
The life work of the engineer consists in the systematic application of natural forces and the systematic development of natural resources in the service of man.
Paper presented (15 Nov 1905) to the Association of American Agricultural Colleges and Experiment Stations, Washington, D.C., Proceedings of the 19th Annual Convention of the Association of American Agricultural Colleges and Experiment Stations (1906), Vol. 19-24, 90. Initials only given in this paper for H.W. Tyler (of Massachussetts); Webmaster tentatively matched with Harry Walter Tyler of M.I.T.
The mathematician pays not the least regard either to testimony or conjecture, but deduces everything by demonstrative reasoning, from his definitions and axioms. Indeed, whatever is built upon conjecture, is improperly called science; for conjecture may beget opinion, but cannot produce knowledge.
In Essays on the Intellectual Powers of Man, Essay 1, chap. 3.
The measure of the probability of an event is the ratio of the number of cases favourable to that event, to the total number of cases favourable or contrary, and all equally possible, or all of which have the same chance.
In 'Règles générales des probabilités', Recherches sur la Probabilités des Jugemens (1837), Chap. 1, 31, as translated in George Boole, An Investigation of the Laws of Thought (1854), 244. From the original French, “La mesure de la probabilité d'un événement, est le rapport du nombre de cas favorables à cet événement, au nombre total de cas favorables ou contraires, et tous également possibles, ou qui ont tous une même chance.”
The method of definition is the method of discovering what the thing under consideration is by means of the definition of that thing in so far as it makes it known. This method involves two procedures, one being by composition and the other by resolution.
As quoted in Alistair Cameron Crombie, Robert Grosseteste and the Origins of Experimental Science, 1100-1700 (1971), 63.
The most satisfactory definition of man from the scientific point of view is probably Man the Tool-maker.
'The Earliest Tool-makers', Antiquity (1956), II 7, 4.
The most striking characteristic of the written language of algebra and of the higher forms of the calculus is the sharpness of definition, by which we are enabled to reason upon the symbols by the mere laws of verbal logic, discharging our minds entirely of the meaning of the symbols, until we have reached a stage of the process where we desire to interpret our results. The ability to attend to the symbols, and to perform the verbal, visible changes in the position of them permitted by the logical rules of the science, without allowing the mind to be perplexed with the meaning of the symbols until the result is reached which you wish to interpret, is a fundamental part of what is called analytical power. Many students find themselves perplexed by a perpetual attempt to interpret not only the result, but each step of the process. They thus lose much of the benefit of the labor-saving machinery of the calculus and are, indeed, frequently incapacitated for using it.
In 'Uses of Mathesis', Bibliotheca Sacra (Jul 1875), 32, 505.
The new definition of psychiatry is the care of the id by the odd.
The oil industry is a stunning example of how science, technology, and mass production can divert an entire group of companies from their main task. ... No oil company gets as excited about the customers in its own backyard as about the oil in the Sahara Desert. ... But the truth is, it seems to me, that the industry begins with the needs of the customer for its products. From that primal position its definition moves steadily back stream to areas of progressively lesser importance until it finally comes to rest at the search for oil.
In 'Marketing Myopia' originally published in Harvard Business Review (). Reprinted in Harvard Business Review Classics: Marketing Myopia (2008), 66-71.
The operative definition of an expert … someone who doesn’t make small mistakes.
In Seeing Red: Redshifts, Cosmology and Academic Science (1998), 274.
The presentation of mathematics where you start with definitions, for example, is simply wrong. Definitions aren't the places where things start. Mathematics starts with ideas and general concepts, and then definitions are isolated from concepts. Definitions occur somewhere in the middle of a progression or the development of a mathematical concept. The same thing applies to theorems and other icons of mathematical progress. They occur in the middle of a progression of how we explore the unknown.
Interview for website of the Mathematical Association of America.
The real problem in speech is not precise language. The problem is clear language. The desire is to have the idea clearly communicated to the other person. [But] precise language is not precise in any sense if you deal with the real objects of the world, and is overly pedantic and quite confusing to use it unless there are some special subtleties which have to be carefully distinguished.
Criticizing “overly pedantic” language in proposed textbooks for a modified arithmetic course for grades 1-8 in California schools. In article, 'New Textbooks for the ‘New’ Mathematics', Engineering and Science (Mar 1965), 28, No. 6. Collected in Perfectly Reasonable Deviations from the Beaten Track: The Letters of Richard Feynman (2008), 454. He was writing as a member of the California State Curriculum Committee
The reasoning of mathematicians is founded on certain and infallible principles. Every word they use conveys a determinate idea, and by accurate definitions they excite the same ideas in the mind of the reader that were in the mind of the writer. When they have defined the terms they intend to make use of, they premise a few axioms, or self-evident principles, that every one must assent to as soon as proposed. They then take for granted certain postulates, that no one can deny them, such as, that a right line may be drawn from any given point to another, and from these plain, simple principles they have raised most astonishing speculations, and proved the extent of the human mind to be more spacious and capacious than any other science.
In Diary, Works (1850), Vol. 2, 21.
The results of mathematics are seldom directly applied; it is the definitions that are really useful. Once you learn the concept of a differential equation, you see differential equations all over, no matter what you do. This you cannot see unless you take a course in abstract differential equations. What applies is the cultural background you get from a course in differential equations, not the specific theorems. If you want to learn French, you have to live the life of France, not just memorize thousands of words. If you want to apply mathematics, you have to live the life of differential equations. When you live this life, you can then go back to molecular biology with a new set of eyes that will see things you could not otherwise see.
In 'A Mathematician's Gossip', Indiscrete Thoughts (2008), 213.
The same applies to the concept of force as does to any other physical concept: Verbal definitions are meaningless; real definitions are given through a measuring process.
As given in epigraph, without citation, in Eberhard Zeidler and Juergen Quandt (trans.), Nonlinear Functional Analysis and its Applications: IV: Applications to Mathematical Physics (2013), 9.
The self-fulfilling prophecy is, in the beginning, a false definition of the situation evoking a new behavior which makes the originally false conception come true. The specious validity of the self-fulfilling prophecy perpetuates a reign of error. For the prophet will cite the actual course of events as proof that he was right from the very beginning. … Such are the perversities of social logic.
In article, 'The Self-Fulfilling Prophecy', The Antioch Review (Summer 1948), 8, No. 2, 195-196. Included as Chap. 7 of Social Theory and Social Structure (1949), 181-195. Note: Merton coined the expression “self-fulfilling prophecy.”
The speculative propositions of mathematics do not relate to facts; … all that we are convinced of by any demonstration in the science, is of a necessary connection subsisting between certain suppositions and certain conclusions. When we find these suppositions actually take place in a particular instance, the demonstration forces us to apply the conclusion. Thus, if I could form a triangle, the three sides of which were accurately mathematical lines, I might affirm of this individual figure, that its three angles are equal to two right angles; but, as the imperfection of my senses puts it out of my power to be, in any case, certain of the exact correspondence of the diagram which I delineate, with the definitions given in the elements of geometry, I never can apply with confidence to a particular figure, a mathematical theorem. On the other hand, it appears from the daily testimony of our senses that the speculative truths of geometry may be applied to material objects with a degree of accuracy sufficient for the purposes of life; and from such applications of them, advantages of the most important kind have been gained to society.
In Elements of the Philosophy of the Human Mind (1827), Vol. 3, Chap. 1, Sec. 3, 180.
The steady progress of physics requires for its theoretical formulation a mathematics which get continually more advanced. ... it was expected that mathematics would get more and more complicated, but would rest on a permanent basis of axioms and definitions, while actually the modern physical developments have required a mathematics that continually shifts its foundation and gets more abstract. Non-euclidean geometry and noncommutative algebra, which were at one time were considered to be purely fictions of the mind and pastimes of logical thinkers, have now been found to be very necessary for the description of general facts of the physical world. It seems likely that this process of increasing abstraction will continue in the future and the advance in physics is to be associated with continual modification and generalisation of the axioms at the base of mathematics rather than with a logical development of any one mathematical scheme on a fixed foundation.
Introduction to a paper on magnetic monopoles, 'Quantised singularities in the electromagnetic field', Proceedings of the Royal Society of Lonndon (1931), A, 133 60. In Helge Kragh, Dirac: a Scientific Biography (1990), 208.
The subject-matter of Archaeology is threefold—the Oral, the Written and the Monumental.
In Lecture to the Oxford meeting of the Archaeological Institute (18 Jun 1850), printed in 'On the Study of Achaeology', Archaeological Journal (1851), 8, 2.
The symbol A is not the counterpart of anything in familiar life. To the child the letter A would seem horribly abstract; so we give him a familiar conception along with it. “A was an Archer who shot at a frog.” This tides over his immediate difficulty; but he cannot make serious progress with word-building so long as Archers, Butchers, Captains, dance round the letters. The letters are abstract, and sooner or later he has to realise it. In physics we have outgrown archer and apple-pie definitions of the fundamental symbols. To a request to explain what an electron really is supposed to be we can only answer, “It is part of the A B C of physics”.
In Introduction to The Nature of the Physical World (1928), xiv.
The whole value of science consists in the power which it confers upon us of applying to one object the knowledge acquired from like objects; and it is only so far, therefore, as we can discover and register resemblances that we can turn our observations to account.
Principles of Science: A Treatise on Logic and Scientific Method (1874, 2nd ed., 1913), 1.
The word “comet” has been derived by some from the Latin coma, a tail; but the better derivation is comma, because it never can come to a full stop.
In Gilbert Abbott À Beckett et al., The Comic Almanack: An Ephemeris in Jest and Earnest, Containing Merry Tales, Humerous Poetry, Quips, and Oddities: 2nd Series, 1844-1853 (1892), Vol. 2.
The word “definition” has come to have a dangerously reassuring sound, owing no doubt to its frequent occurrence in logical and mathematical writings.
In 'Two Dogmas of Empiricism', From a Logical Point of View: Nine Logico-Philosophical Essays (1953, 1961), 26.
The word “mathematics” is a Greek word and, by origin, it means “something that has been learned or understood,” or perhaps “acquired knowledge,” or perhaps even, somewhat against grammar, “acquirable knowledge,” that is, “learnable knowledge,” that is, “knowledge acquirable by learning.”
'Why Mathematics Grows', Journal of the History of Ideas (Jan-Mar 1965), 26, No. 1, 4. In Salomon Bochner and Robert Clifford Gunning (ed.) Collected Papers of Salomon Bochner (1992), Vol. 4, 192.
There are diverse views as to what makes a science, but three constituents will be judged essential by most, viz: (1) intellectual content, (2) organization into an understandable form, (3) reliance upon the test of experience as the ultimate standard of validity. By these tests, mathematics is not a science, since its ultimate standard of validity is an agreed-upon sort of logical consistency and provability.
In 'The Future of Data Analysis', Annals of Mathematical Statistics (1962), 33, No. 1, 5-6.
There are four classes of Idols which beset men’s minds. To these for distinction’s sake I have assigned names,—calling the first class Idols of the Tribe; the second, Idols of the Cave; the third, Idols of the Market Place; the fourth, Idols of the Theatre …
The Idols of the Tribe have their foundation in human nature itself, and in the tribe or race of men. For it is a false assertion that the sense of man is the measure of things. On the contrary, all perceptions as well of the sense as of the mind are according to the measure of the individual and not according to the measure of the universe. And the human understanding is like a false mirror, which, receiving rays irregularly, distorts and discolours the nature of things by mingling its own nature with it.
The Idols of the Cave are the idols of the individual man. For every one (besides the errors common to human nature in general) has a cave or den of his own, which refracts and discolours the light of nature; owing either to his own proper and peculiar nature; or to his education and conversation with others; or to the reading of books, and the authority of those whom he esteems and admires; or to the differences of impressions, accordingly as they take place in a mind preoccupied and predisposed or in a mind indifferent and settled; or the like.
There are also Idols formed by the intercourse and association of men with each other, which I call Idols of the Market-place, on account of the commerce and consort of men there. For it is by discourse that men associate; and words are imposed according to the apprehension of the vulgar, and therefore the ill and unfit choice of words wonderfully obstructs the understanding. Nor do the definitions or explanations where with in some things learned men are wont to guard and defend themselves, by any means set the matter right. But words plainly force and overrule the understanding, and throw all into confusion, and lead men away into numberless empty controversies and idle fancies.
Lastly, there are Idols which have immigrated into men’s minds from the various dogmas of philosophies, and also from wrong laws of demonstration. These I call Idols of the Theatre; because in my judgment all the received systems are but so many stage-plays, representing worlds of their own creation after an unreal and scenic fashion.
The Idols of the Tribe have their foundation in human nature itself, and in the tribe or race of men. For it is a false assertion that the sense of man is the measure of things. On the contrary, all perceptions as well of the sense as of the mind are according to the measure of the individual and not according to the measure of the universe. And the human understanding is like a false mirror, which, receiving rays irregularly, distorts and discolours the nature of things by mingling its own nature with it.
The Idols of the Cave are the idols of the individual man. For every one (besides the errors common to human nature in general) has a cave or den of his own, which refracts and discolours the light of nature; owing either to his own proper and peculiar nature; or to his education and conversation with others; or to the reading of books, and the authority of those whom he esteems and admires; or to the differences of impressions, accordingly as they take place in a mind preoccupied and predisposed or in a mind indifferent and settled; or the like.
There are also Idols formed by the intercourse and association of men with each other, which I call Idols of the Market-place, on account of the commerce and consort of men there. For it is by discourse that men associate; and words are imposed according to the apprehension of the vulgar, and therefore the ill and unfit choice of words wonderfully obstructs the understanding. Nor do the definitions or explanations where with in some things learned men are wont to guard and defend themselves, by any means set the matter right. But words plainly force and overrule the understanding, and throw all into confusion, and lead men away into numberless empty controversies and idle fancies.
Lastly, there are Idols which have immigrated into men’s minds from the various dogmas of philosophies, and also from wrong laws of demonstration. These I call Idols of the Theatre; because in my judgment all the received systems are but so many stage-plays, representing worlds of their own creation after an unreal and scenic fashion.
From Novum Organum (1620), Book 1, Aphorisms 39, 41-44. Translated as The New Organon: Aphorisms Concerning the Interpretation of Nature and the Kingdom of Man), collected in James Spedding, Robert Ellis and Douglas Heath (eds.), The Works of Francis Bacon (1857), Vol. 4, 53-55.
There are several kinds of truths, and it is customary to place in the first order mathematical truths, which are, however, only truths of definition. These definitions rest upon simple, but abstract, suppositions, and all truths in this category are only constructed, but abstract, consequences of these definitions ... Physical truths, to the contrary, are in no way arbitrary, and do not depend on us.
'Premier Discours: De la Manière d'Étudier et de Traiter l'Histoire naturelle', Histoire Naturelle, Generale et Particulière, Avec la Description du Cabinet du Roi (1749), Vol. I, 53-4. Trans. Phillip R. Sloan.
There could not be a language more universal and more simple, more exempt from errors and obscurities, that is to say, more worthy of expressing the invariable relations of natural objects. Considered from this point of view, it is coextensive with nature itself; it defines all the sensible relations, measures the times, the spaces, the forces, the temperatures; this difficult science is formed slowly, but it retains all the principles it has once acquired. It grows and becomes more certain without limit in the midst of so many errors of the human mind.
From Théorie Analytique de la Chaleur, Discours Préliminaire (Theory of Heat, Introduction), quoted as translated in F.R. Moulton, 'The Influence of Astronomy on Mathematics', Science (10 Mar 1911), N.S. Vol. 33, No. 845, 359.
There is a hidden healthcare system with clear definitions and roles. Eighty-five percent of
healthcare takes place in a big pool without the ‘benefit’ of ‘medical clergy’.
As quoted in 'Aphorism of the Month', Journal of Epidemiology and Community Health (Nov 2005), 59, No. 11, 933.
There is no rigorous definition of rigor.
In Mathematics: The Loss of Certainty (1982), 315.
There is one class of mind that loves to lean on rules and definitions, and another that discards them as far as possible. A faddist will generally ask for a definition of faddism, and one who is not a faddist will be impatient of being asked to give one.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 221.
There is one class of mind that loves to lean on rules and definitions, and another that discards them as far as possible. A faddist will generally ask for a definition of faddism, and one who is not a faddist will be impatient of being asked to give one.
Samuel Butler, Henry Festing Jones (ed.), The Note-Books of Samuel Butler (1917), 221.
There is, however, no genius so gifted as not to need control and verification. ... [T]he brightest flashes in the world of thought are incomplete until they have been proved to have their counterparts in the world of fact. Thus the vocation of the true experimentalist may be defined as the continued exercise of spiritual insight, and its incessant correction and realisation. His experiments constitute a body, of which his purified intuitions are, as it were, the soul.
In 'Vitality', Scientific Use of the Imagination and Other Essays (1872), 43.
These microscopic organisms form an entire world composed of species, families and varieties whose history, which has barely begun to be written, is already fertile in prospects and findings of the highest importance. The names of these organisms are very numerous and will have to be defined and in part discarded. The word microbe which has the advantage of being shorter and carrying a more general meaning, and of having been approved by my illustrious friend, M. Littré, the most competent linguist in France, is one we will adopt.
In paper read to the Académie de Medecine (Mar 1878). In Charles-Emile Sedillot, 'Influence de M. Pasteur sur les progres de la chirurgie' [Influence of Pasteur on the progress of surgery].
These sciences, Geometry, Theoretical Arithmetic and Algebra, have no principles besides definitions and axioms, and no process of proof but deduction; this process, however, assuming a most remarkable character; and exhibiting a combination of simplicity and complexity, of rigour and generality, quite unparalleled in other subjects.
In The Philosophy of the Inductive Sciences (1858), Part 1, Bk. 2, chap. 1, sect. 2.
This discovery, indeed, is almost of that kind which I call serendipity, a very expressive word, which as I have nothing better to tell you, I shall endeavour to explain to you: you will understand it better by the derivation than by the definition. I once read a silly fairy tale, called The Three Princes of Serendip: as their highnesses travelled, they were always making discoveries, by accidents and sagacity, of things which they were not in quest of: for instance, one of them discovered that a mule blind of the right eye had travelled the same road lately, because the grass was eaten only on the left side, where it was worse than on the right—now do you understand serendipity?
Letter to Sir Horace Mann (28 Jan 1754), in W. S. Lewis, Warren Hunting Smith and George L. Lam (eds.), Horace Walpole's Correspondence with Sir Horace Mann (1960), Vol. 20, 407-408.
This method is, to define as the number of a class the class of all classes similar to the given class. Membership of this class of classes (considered as a predicate) is a common property of all the similar classes and of no others; moreover every class of the set of similar classes has to the set of a relation which it has to nothing else, and which every class has to its own set. Thus the conditions are completely fulfilled by this class of classes, and it has the merit of being determinate when a class is given, and of being different for two classes which are not similar. This, then, is an irreproachable definition of the number of a class in purely logical terms.
The Principles of Mathematics (1903), 115.
Time is that which is measured by a clock. This is a sound way of looking at things. A quantity like time, or any other physical measurement, does not exist in a completely abstract way. We find no sense in talking about something unless we specify how we measure it. It is the definition by the method of measuring a quantity that is the one sure way of avoiding talking nonsense about this kind of thing.
From Relativity and Common Sense: A New Approach to Einstein (1980), 65.
To make “beauty” the objects of the æsthetic emotion, we must give to the word an over-strict and unfamiliar definition.
In Art (1913), 14.
To take one of the simplest cases of the dissipation of energy, the conduction of heat through a solid—consider a bar of metal warmer at one end than the other and left to itself. To avoid all needless complication, of taking loss or gain of heat into account, imagine the bar to be varnished with a substance impermeable to heat. For the sake of definiteness, imagine the bar to be first given with one half of it at one uniform temperature, and the other half of it at another uniform temperature. Instantly a diffusing of heat commences, and the distribution of temperature becomes continuously less and less unequal, tending to perfect uniformity, but never in any finite time attaining perfectly to this ultimate condition. This process of diffusion could be perfectly prevented by an army of Maxwell’s ‘intelligent demons’* stationed at the surface, or interface as we may call it with Prof. James Thomson, separating the hot from the cold part of the bar.
* The definition of a ‘demon’, according to the use of this word by Maxwell, is an intelligent being endowed with free will, and fine enough tactile and perceptive organisation to give him the faculty of observing and influencing individual molecules of matter.
* The definition of a ‘demon’, according to the use of this word by Maxwell, is an intelligent being endowed with free will, and fine enough tactile and perceptive organisation to give him the faculty of observing and influencing individual molecules of matter.
In 'The Kinetic Theory of the Dissipation of Energy', Nature (1874), 9, 442.
To the behaviourist a man is only a nexus of stimuli and responses, because the method of investigation, by its own definitions and axioms, is merely the study of the relations between stimuli and responses.
In A Shorter History of Science (1944), 137.
Today it is no longer questioned that the principles of the analysts are the more far-reaching. Indeed, the synthesists lack two things in order to engage in a general theory of algebraic configurations: these are on the one hand a definition of imaginary elements, on the other an interpretation of general algebraic concepts. Both of these have subsequently been developed in synthetic form, but to do this the essential principle of synthetic geometry had to be set aside. This principle which manifests itself so brilliantly in the theory of linear forms and the forms of the second degree, is the possibility of immediate proof by means of visualized constructions.
In Riemannsche Flächen (1906), Bd. 1, 234.
Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.
In On Aggression (1966, 2002), 279.
Using any reasonable definition of a scientist, we can say that 80 to 90 percent of all the scientists that have ever lived are alive now. Alternatively, any young scientist, starting now and looking back at the end of his career upon a normal life span, will find that 80 to 90 percent of all scientific work achieved by the end of the period will have taken place before his very eyes, and that only 10 to 20 percent will antedate his experience.
Little Science, Big Science (1963), 1-2.
We … find a number of quotations illustrating the use of the word [probability], most of them taken from philosophical works. I shall only refer to a few examples: “The probable is something which lies midway between truth and error” (Thomasius, 1688); “An assertion, of which the contrary is not completely self-contradictory or impossible, is called probable” (Reimarus). Kant says: “That which, if it were held as truth, would be more than half certain, is called probable.”
In Probability, Statistics, and Truth (1939), 3.
We are Marxists, and Marxism teaches that in our approach to a problem we should start from objective facts, not from abstract definitions, and that we should derive our guiding principles, policies, and measures from an analysis of these facts.
As quoted in William Theodore De Bary, Sources of Chinese Tradition (1960), 929.
We can’t define anything precisely. If we attempt to, we get into that paralysis of thought that comes to philosophers… one saying to the other: “You don’t know what you are talking about!” The second one says: “What do you mean by know? What do you mean by talking? What do you mean by you?”
In 'Motion', The Feynman Lectures on Physics (1961), Vol. 1, 8-2.
We cannot, of course, give a definition of matter which will satisfy the metaphysician, but the naturalist may be content to know matter as that which can be perceived by the senses, or as that which can be acted upon by, or can exert, force.
In William Thomson and Peter Guthrie Tait, Treatise on Natural Philosophy (1867), Vol. 1, 161.
We find no sense in talking about something unless we specify how we measure it; a definition by the method of measuring a quantity is the one sure way of avoiding talking nonsense...
in Relativity and Common Sense (1964)
We hold these truths to be self-evident.
Franklin's edit to the assertion of religion in Thomas Jefferson's original wording, “We hold these truths to be sacred and undeniable” in a draft of the Declaration of Independence changes it instead into an assertion of rationality. The scientific mind of Franklin drew on the scientific determinism of Isaac Newton and the analytic empiricism of David Hume and Gottfried Leibniz. In what became known as “Hume's Fork” the latters' theory distinguished between synthetic truths that describe matters of fact, and analytic truths that are self-evident by virtue of reason and definition.
Franklin's edit to the assertion of religion in Thomas Jefferson's original wording, “We hold these truths to be sacred and undeniable” in a draft of the Declaration of Independence changes it instead into an assertion of rationality. The scientific mind of Franklin drew on the scientific determinism of Isaac Newton and the analytic empiricism of David Hume and Gottfried Leibniz. In what became known as “Hume's Fork” the latters' theory distinguished between synthetic truths that describe matters of fact, and analytic truths that are self-evident by virtue of reason and definition.
As explained by Walter Isaacson in Benjamin Franklin: An American Life (2004), 312.
We need constantly new accessions of truth as to the universe and better definition of the truths which are old. Such knowledge, tested and placed in order, we call science. Science is the gathered wisdom of the race.
From Presidential Address (5 Dec 1896) to the Biological Society of Washington, 'The Malarial Parasite and Other Pathogenic Protozoa', Popular Science Monthly (Mar 1897), 642.
We shall therefore say that a program has common sense if it automatically deduces for itself a sufficient wide class of immediate consequences of anything it is told and what it already knows. ... Our ultimate objective is to make programs that learn from their experience as effectively as humans do.
'Programs with Common Sense', (probably the first paper on AI), delivered to the Teddington Conference on the Mechanization of Thought Processes (Dec 1958). Printed in National Physical Laboratory, Mechanisation of Thought Processes: Proceedings of a Symposium Held at the National Physical Laboratory on 24th, 25th, 26th and 27th November 1958 (1959), 78. Also Summary in John McCarthy and Vladimir Lifschitz (ed.), Formalizing Common Sense: Papers by John McCarthy (1990), 9-10.
Were I asked to define it, I should reply that archæology is that science which enables us to register and classify our knowledge of the sum of man’s achievement in those arts and handicrafts whereby he has, in time past, signalized his passage from barbarism to civilization.
In Pharaohs, Fellahs and Explorers (1891), 24.
What is a good definition? For the philosopher or the scientist, it is a definition which applies to all the objects to be defined, and applies only to them; it is that which satisfies the rules of logic. But in education it is not that; it is one that can be understood by the pupils.
Science and Method (1914, 2003), 117.
What is a weed? A plant whose virtues have not been discovered.
From Lecture delivered at the Old South Church (30 Mar 1878), published as a booklet, Fortune of the Republic (1878), 3.
What is a weed? I have heard it said that there are sixty definitions. For me, a weed is a plant out of place.
In Flowering Earth (1939), 156. Note that this definition was in use before Peattie was born, for example “the true definition of a weed is ‘a plant out of place’” appears in Alex Brown, The Coffee Planter's Manual (1880), 121.
What is mathematics? To give a satisfactory definition is difficult, if not impossible.
In Lectures on Fundamental Concepts of Algebra and Geometry (1911), 1.
What merely annoys and discourages a person not accustomed to thinking … is a stimulus and guide to the trained enquirer. … It either brings to light a new problem or helps to define and clarify the problem.
In How We Think (1933), 114.
What, in fact, is mathematical discovery? It does not consist in making new combinations with mathematical entities that are already known. That can be done by anyone, and the combinations that could be so formed would be infinite in number, and the greater part of them would be absolutely devoid of interest. Discovery consists precisely in not constructing useless combinations, but in constructing those that are useful, which are an infinitely small minority. Discovery is discernment, selection.
In Science et Méthode (1920), 48, as translated by Francis Maitland, in Science and Method (1908, 1952), 50-51. Also seen elsewhere translated with “invention” in place of “discovery”.
Whatever universe a professor believes in must at any rate be a universe that lends itself to lengthy discourse. A universe definable in two sentences is something for which the professorial intellect has no use. No faith in anything of that cheap kind!
First of eight lectures on ‘Pragmatism: A New Name For an Old Way of Thinking’ given at the Lowell Institute, Boston and the Departments of Philosophy and Psychology, Columbia University. In The Popular Science Monthly (Mar 1907), 193.
Wherever man has left the stamp of mind on brute-matter; whether we designate his work as structure, texture, or mixture, mechanical or chymical; whether the result be a house, a ship, a garment, a piece of glass, or a metallic implement, these memorials of economy and invention will always be worthy of the attention of the Archaeologist.
In Lecture to the Oxford meeting of the Archaeological Institute (18 Jun 1850), printed in 'On the Study of Achaeology', Archaeological Journal (1851), 8, No. 29, 25.
Why should an hypothesis, suggested by a scientist, be accepted as true until its truth is established? Science should be the last to make such a demand because science to be truly science is classified knowledge; it is the explanation of facts. Tested by this definition, Darwinism is not science at all; it is guesses strung together.
In chapter, 'The Origin of Man', In His Image (1922), 94.
You may perceive something of the distinction which I think necessary to keep in view between art and science, between the artist and the man of knowledge, or the philosopher. The man of knowledge, the philosopher, is he who studies and acquires knowledge in order to improve his own mind; and with a desire of extending the department of knowledge to which he turns his attention, or to render it useful to the world, by discoveries, or by inventions, which may be the foundation of new arts, or of improvements in those already established. Excited by one or more of these motives, the philosopher employs himself in acquiring knowledge and in communicating it. The artist only executes and practises what the philosopher or man of invention has discovered or contrived, while the business of the trader is to retail the productions of the artist, exchange some of them for others, and transport them to distant places for that purpose.
From the first of a series of lectures on chemistry, collected in John Robison (ed.), Lectures on the Elements of Chemistry: Delivered in the University of Edinburgh (1807), Vol. 1, 3.
Your theories are those which you and many other people find easiest and pleasantest to believe, but, so far as I can see, they have no foundation other than they lead to a pleasant view of life … I agree that faith is essential to success in life … but I do not accept your definition of faith, i.e. belief in life after death. In my view, all that is necessary for faith is the belief that by doing our best we shall come nearer to success and that success in our aims (the improvement of the lot of mankind, present and future) is worth attaining … I maintain that faith in this world is perfectly possible without faith in another world.
Letter to her father, Ellis Franklin (undated, summer 1940? while she was an undergraduate at Cambridge). Excerpted in Brenda Maddox, The Dark Lady of DNA (2002), 61.
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
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