La théorie est l’hypothèse vérifiée, après qu’elle a été soumise au contrôle du raisonnement et de la critique expérimentale. La meilleure théorie est celle qui a été vérifiée par le plus grand nombre de faits. Mais une théorie, pour rester bonne, doit toujours se modifier avec les progrès de la science et demeurer constamment soumise à la vérification et à la critique des faits nouveaux qui apparaissent.
A theory is a verified hypothesis, after it has been submitted to the control of reason and experimental criticism. The soundest theory is one that has been verified by the greatest number of facts. But to remain valid, a theory must be continually altered to keep pace with the progress of science and must be constantly resubmitted to verification and criticism as new facts appear.

Again there is another great and powerful cause why the sciences have made but little progress; which is this. It is not possible to run a course aright when the goal itself has not been rightly placed.

Amputations are much less frequent now than formerly, and there is little doubt that, in the present rapid advance in the science of surgery, and the greater perfection in its art, the time is not far removed when amputations for other cause than gangrene will be comparatively rare.

Be you in what line of life you may, it will be amongst your misfortunes if you have not time properly to attend to [money management]; for. ... want of attention to pecuniary matters … has impeded the progress of science and of genius itself.

But by far the greatest obstacle to the progress of science and to the undertaking of new tasks and provinces therein is found in this—that men despair and think things impossible.

But weightier still are the contentment which comes from work well done, the sense of the value of science for its own sake, insatiable curiosity, and, above all, the pleasure of masterly performance and of the chase. These are the effective forces which move the scientist. The first condition for the progress of science is to bring them into play.

Every answer given arouses new questions. The progress of science is matched by an increase in the hidden and mysterious.

False facts are highly injurious to the progress of science, for they often long endure; but false views, if supported by some evidence, do little harm, as every one takes a salutary pleasure in proving their falseness; and when this is done, one path towards error is closed and the road to truth is often at the same time opened.

Hitherto the progress of science has been slow, and subject to constant error and revision. But as soon as physical research begins to go hand in hand with moral or psychical research, it will advance with a rapidity hitherto unimagined, each assisting and classifying the other.

I am for encouraging the progress of science in all it’s branches.

I know that certain minds would regard as audacious the idea of relating the laws which preside over the play of our organs to those laws which govern inanimate bodies; but, although novel, this truth is none the less incontestable. To hold that the phenomena of life are entirely distinct from the general phenomena of nature is to commit a grave error, it is to oppose the continued progress of science.

I would not want to generalize to the extent that adversity is the only road to effective innovative science, or art, but the progress of science is often spectacularly disorderly. James Joyce once commented that he survived by “cunning and exile”.

If it is true as Whewell says, that the essence of the triumphs of Science and its progress consists in that it enables us to consider evident and necessary, views which our ancestors held to be unintelligible and were unable to comprehend, then the extension of the number concept to include the irrational, and we will at once add, the imaginary, is the greatest forward step which pure mathematics has ever taken.

In most sciences one generation tears down what another has built, and what one has established, another undoes. In mathematics alone each generation adds a new storey to the old structure.

It surely can be no offence to state, that the progress of science has led to new views, and that the consequences that can be deduced from the knowledge of a hundred facts may be very different from those deducible from five. It is also possible that the facts first known may be the exceptions to a rule and not the rule itself, and generalisations from these first-known facts, though useful at the time, may be highly mischievous, and impede the progress of the science if retained when it has made some advance.

Man is an animal with primary instincts of survival. Consequently his ingenuity has developed first and his soul afterwards. The progress of science is far ahead of man's ethical behavior.

Much as I venerate the name of Newton, I am not therefore obliged to believe that he was infallible. I see … with regret that he was liable to err, and that his authority has, perhaps, sometimes even retarded the progress of science.

Much is said about the progress of science in these centuries. I should say that the useful results of science had accumulated, but that there had been no accumulation of knowledge, strictly speaking, for posterity; for knowledge is to be acquired only by corresponding experience. How can be know what we are told merely? Each man can interpret another’s experience only by his own.

Of the various anesthetics which have been introduced for surgical use, only two deserve to be considered, and in order of preference they are ether and chloroform. In general, there is no comparison between these agents. Ether is so much safer than chloroform that the latter is fast disappearing in practice. In the present rapid progress of science it can not but be a short while until chloroform will only he employed in a very limited number of cases. The estimated death-rate after ether is 1 in 20,000, in chloroform 1 in 3,000. All of the objections to ether by the advocates of chloroform narcosis—namely, its slowness of action, irritation of the respiratory tract, nausea and vomiting, inflammability, extra quantity required, etc.—fade into insignificance when brought face to face with the fact that about seven lives are sacrificed by chloroform to one by ether.

Since science's competence extends to observable and measurable phenomena, not to the inner being of things, and to the means, not to the ends of human life, it would be nonsense to expect that the progress of science will provide men with a new type of metaphysics, ethics, or religion.

The attempt of Lavoisier to reform chemical nomenclature is premature. One single experiment may destroy the whole filiation of his terms; and his string of sulphates, sulphites, and sulphures, may have served no end than to have retarded the progress of science by a jargon, from the confusion of which time will be requisite to extricate us.

The chemist and the engineer have a vital interest in knowing the processes that have fallen into disuse, but to which the very progress of science may give from one day to the next a new career. The history of science is to them, so to say, what forsaken mines are to the prospector.

The Christians who engaged in infamous persecutions and shameful inquisitions were not evil men but misguided men. The churchmen who felt they had an edict from God to withstand the progress of science, whether in the form of a Copernican revolution or a Darwinian theory of natural selection, were not mischievous men but misinformed men. And so Christ’s words from the cross are written in sharp-edged terms across some of the most inexpressible tragedies of history: 'They know not what they do'.

The Congress shall have power to ... promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries.
Founding U.S. Patents.

The great testimony of history shows how often in fact the development of science has emerged in response to technological and even economic needs, and how in the economy of social effort, science, even of the most abstract and recondite kind, pays for itself again and again in providing the basis for radically new technological developments. In fact, most people—when they think of science as a good thing, when they think of it as worthy of encouragement, when they are willing to see their governments spend substance upon it, when they greatly do honor to men who in science have attained some eminence—have in mind that the conditions of their life have been altered just by such technology, of which they may be reluctant to be deprived.

The invention of the differential calculus marks a crisis in the history of mathematics. The progress of science is divided between periods characterized by a slow accumulation of ideas and periods, when, owing to the new material for thought thus patiently collected, some genius by the invention of a new method or a new point of view, suddenly transforms the whole subject on to a higher level.

The one lesson that comes out of all our theorizing and experimenting is that there is only one really scientific progressive method; and that is the method of trial and error.

The progress of Science consists in observing interconnections and in showing with a patient ingenuity that the events of this ever-shifting world are but examples of a few general relations, called laws. To see what is general in what is particular, and what is permanent in what is transitory, is the aim of scientific thought.

The progress of science depends less than is usually believed on the efforts and performance of the individual genius ... many important discoveries have been made by men of ordinary talents, simply because chance had made them, at the proper time and in the proper place and circumstances, recipients of a body of doctrines, facts and techniques that rendered almost inevitable the recognition of an important phenomenon. It is surprising that some historian has not taken malicious pleasure in writing an anthology of 'one discovery' scientists. Many exciting facts have been discovered as a result of loose thinking and unimaginative experimentation, and described in wrappings of empty words. One great discovery does not betoken a great scientist; science now and then selects insignificant standard bearers to display its banners.

The progress of science has always been the result of a close interplay between our concepts of the universe and our observations on nature. The former can only evolve out of the latter and yet the latter is also conditioned greatly by the former. Thus in our exploration of nature, the interplay between our concepts and our observations may sometimes lead to totally unexpected aspects among already familiar phenomena.

The progress of Science is generally regarded as a kind of clean, rational advance along a straight ascending line; in fact it has followed a zig-zag course, at times almost more bewildering than the evolution of political thought. The history of cosmic theories, in particular, may without exaggeration be called a history of collective obsessions and controlled schizophrenias; and the manner in which some of the most important individual discoveries were arrived at reminds one more of a sleepwalker’s performance than an electronic brain’s.

The progress of science is often affected more by the frailties of humans and their institutions than by the limitations of scientific measuring devices. The scientific method is only as effective as the humans using it. It does not automatically lead to progress.

The progress of science is strewn, like an ancient desert trail, with the bleached skeletons of discarded theories which once seemed to possess eternal life.

The progress of science is tremendously disorderly, and the motivations that lead to this progress are tremendously varied, and the reasons why scientists go into science, the personal motivations, are tremendously varied. I have said … in the Beckett lecture, at least one particular point that seems to be missed; that science is a haven for freaks, that people go into science because they are misfits, and that it is a sheltered place where they can spin their own yarn and have recognition, be tolerated and happy, and have approval for it.

The progress of science requires more than new data; it needs novel frameworks and contexts. And where do these fundamentally new views of the world arise? They are not simply discovered by pure observation; they require new modes of thought. And where can we find them, if old modes do not even include the right metaphors? The nature of true genius must lie in the elusive capacity to construct these new modes from apparent darkness. The basic chanciness and unpredictability of science must also reside in the inherent difficulty of such a task.

Without preparing fluorine, without being able to separate it from the substances with which it is united, chemistry has been able to study and to analyze a great number of its compounds. The body was not isolated, and yet its place was marked in our classifications. This well demonstrates the usefulness of a scientific theory, a theory which is regarded as true during a certain time, which correlates facts and leads the mind to new hypotheses, the first causes of experimentation; which, little by little, destroy the theory itself, in order to replace it by another more in harmony with the progress of science.
[Describing the known history of fluorine compounds before his isolation of the element.]

You can hardly convince a man of error in a life-time, but must content yourself with the reflection that the progress of science is slow. If he is not convinced, his grand-children may be. The geologists tell us that it took one hundred years to prove that fossils are organic, and one hundred and fifty more, to prove that they are not to be referred to the Noachian deluge.

You will be able to appreciate the influence of such an Engine on the future progress of science. I live in a country which is incapable of estimating it.

You will be able to appreciate the influence of such an Engine on the future progress of science. I live in a country which is incapable of estimating it.

Your remarks upon chemical notation with the variety of systems which have arisen, &c., &c., had almost stirred me up to regret publicly that such hindrances to the progress of science should exist. I cannot help thinking it a most unfortunate thing that men who as experimentalists & philosophers are the most fitted to advance the general cause of science & knowledge should by promulgation of their own theoretical views under the form of nomenclature, notation, or scale, actually retard its progress.