“Biodiversity” … is the key to the maintenance of the world as we know it. Life in a local site struck down by a passing storm springs back quickly because enough diversity still exists. … This is the assembly of life that took a billion years to evolve. It has eaten the storms—folded them into its genes—and created the world that created us. It holds the world steady.

The constancy of the internal environment is the condition for free and independent life: the mechanism that makes it possible is that which assured the maintenance, with the internal environment, of all the conditions necessary for the life of the elements.

A cell has a history; its structure is inherited, it grows, divides, and, as in the embryo of higher animals, the products of division differentiate on complex lines. Living cells, moreover, transmit all that is involved in their complex heredity. I am far from maintaining that these fundamental properties may not depend upon organisation at levels above any chemical level; to understand them may even call for different methods of thought; I do not pretend to know. But if there be a hierarchy of levels we must recognise each one, and the physical and chemical level which, I would again say, may be the level of self-maintenance, must always have a place in any ultimate complete description.

Biological diversity is the key to the maintenance of the world as we know it. Life in a local site struck down by a passing storm springs back quickly: opportunistic species rush in to fill the spaces. They entrain the succession that circles back to something resembling the original state of the environment.

I have attempted to form a judgment as to the conditions for evolution based on the statistical consequences of Mendelian heredity. The most general conclusion is that evolution depends on a certain balance among its factors. There must be a gene mutation, but an excessive rate gives an array of freaks, not evolution; there must be selection, but too severe a process destroys the field of variability, and thus the basis for further advance; prevalence of local inbreeding within a species has extremely important evolutionary consequences, but too close inbreeding leads merely to extinction. A certain amount of crossbreeding is favorable but not too much. In this dependence on balance the species is like a living organism. At all levels of organization life depends on the maintenance of a certain balance among its factors.

I need scarcely say that the beginning and maintenance of life on earth is absolutely and infinitely beyond the range of sound speculation in dynamical science.

I think it is a duty I owe to my profession and to my sex to show that a woman has a right to the practice of her profession and cannot be condemned to abandon it merely because she marries. I cannot conceive how women’s colleges, inviting and encouraging women to enter professions can be justly founded or maintained denying such a principle.
(From a letter Brooks wrote to her dean, knowing that she would be told to resign if she married, she asked to keep her job. Nevertheless, she lost her teaching position at Barnard College in 1906. Dean Gill wrote that “The dignity of women’s place in the home demands that your marriage shall be a resignation.”)

If Russia is to be a great power, it will be, not because of its nuclear potential, faith in God or the president, or Western investment, but thanks to the labor of the nation, faith in knowledge and science and the maintenance and development of scientific potential and education.

In the animal world we have seen that the vast majority of species live in societies, and that they find in association the best arms for the struggle for life: understood, of course, in its wide Darwinian sense—not as a struggle for the sheer means of existence, but as a struggle against all natural conditions unfavourable to the species. The animal species, in which individual struggle has been reduced to its narrowest limits, and the practice of mutual aid has attained the greatest development, are invariably the most numerous, the most prosperous, and the most open to further progress. The mutual protection which is obtained in this case, the possibility of attaining old age and of accumulating experience, the higher intellectual development, and the further growth of sociable habits, secure the maintenance of the species, its extension, and its further progressive evolution. The unsociable species, on the contrary, are doomed to decay.

Now when you cut a forest, an ancient forest in particular, you are not just removing a lot of big trees and a few birds fluttering around in the canopy. You are drastically imperiling a vast array of species within a few square miles of you. The number of these species may go to tens of thousands. … Many of them are still unknown to science, and science has not yet discovered the key role undoubtedly played in the maintenance of that ecosystem, as in the case of fungi, microorganisms, and many of the insects.

Nursing at its highest level encompasses the teaching of the individual to know his body and its functions for the maintenance and promotion of health and prevention of disease. Self-care can be, and is, very efficacious when people are encouraged and guided to learn to care for themselves, whenever possible.

The commonest forms of amateur natural history in the United States are probably gardening, bird watching, the maintenance of aquarium fish, and nature photography.

The individual on his own is stable only so long as he is possessed of self-esteem. The maintenance of self-esteem is a continuous task which taxes all of the individual’s powers and inner resources. We have to prove our worth and justify our existence anew each day. When, for whatever reason, self-esteem is unattainable, the autonomous individual becomes a highly explosive entity. He turns away from an unpromising self and plunges into the pursuit of pride—the explosive substitute for self-esteem. All social disturbances and upheavals have their roots in crises of individual self-esteem, and the great endeavor in which the masses most readily unite is basically a search for pride.

The invertebrated classes include the most numerous and diversified forms of the Animal Kingdom. At the very beginning of our inquiries into their vital powers and acts we are impressed with their important relations to the maintenance of life and organization on this planet, and their influence in purifying the sea and augmenting and enriching the land—relations of which the physiologist conversant only with the vertebrated animals must have remained ignorant.

The maintenance of biological diversity requires special measures that extend far beyond the establishment of nature reserves. Several reasons for this stand out. Existing reserves have been selected according to a number of criteria, including the desire to protect nature, scenery, and watersheds, and to promote cultural values and recreational opportunities. The actual requirements of individual species, populations, and communities have seldom been known, nor has the available information always been employed in site selection and planning for nature reserves. The use of lands surrounding nature reserves has typically been inimical to conservation, since it has usually involved heavy use of pesticides, industrial development, and the presence of human settlements in which fire, hunting, and firewood gathering feature as elements of the local economy.

The maintenance of security … required every member of the project to attend strictly to his own business. The result was an operation whose efficiency was without precedent.

The universality of parasitism as an offshoot of the predatory habit negatives the position taken by man that it is a pathological phenomenon or a deviation from the normal processes of nature. The pathological manifestations are only incidents in a developing parasitism. As human beings intent on maintaining man's domination over nature we may regard parasitism as pathological insofar as it becomes a drain upon human resources. In our efforts to protect ourselves we may make every kind of sacrifice to limit, reduce, and even eliminate parasitism as a factor in human life. Science attempts to define the terms on which this policy of elimination may or may not succeed. We must first of all thoroughly understand the problem, put ourselves in possession of all the facts in order to estimate the cost. Too often it has been assumed that parasitism was abnormal and that it needed only a slight force to reestablish what was believed to be a normal equilibrium without parasitism. On the contrary, biology teaches us that parasitism is a normal phenomenon and if we accept this view we shall be more ready to pay the price of freedom as a permanent and ever recurring levy of nature for immunity from a condition to which all life is subject. The greatest victory of man over nature in the physical realm would undoubtedly be his own delivery from the heavy encumbrance of parasitism with which all life is burdened.

There are those who say that the human kidney was created to keep the blood pure, or more precisely, to keep our internal environment in an ideal balanced state. This I must deny. I grant that the human kidney is a marvelous organ, but I cannot grant that it was purposefully designed to excrete urine or to regulate the composition of the blood or to subserve the physiological welfare of Homo sapiens in any sense. Rather I contend that the human kidney manufactures the kind of urine that it does, and it maintains the blood in the composition which that fluid has, because this kidney has a certain functional architecture; and it owes that architecture not to design or foresight or to any plan, but to the fact that the earth is an unstable sphere with a fragile crust, to the geologic revolutions that for six hundred million years have raised and lowered continents and seas, to the predacious enemies, and heat and cold, and storms and droughts; to the unending succession of vicissitudes that have driven the mutant vertebrates from sea into fresh water, into desiccated swamps, out upon the dry land, from one habitation to another, perpetually in search of the free and independent life, perpetually failing, for one reason or another, to find it.

We cannot rest and sit down lest we rust and decay. Health is maintained only through work. And as it is with all life so it is with science. We are always struggling from the relative to the absolute.

We have before us the restoration of that ancient land whose name was a synonym for abundance, prosperity, and grandeur for many generations. Records as old as those of Egypt and as well attested tell of fertile lands and teeming populations, mighty kings and warriors, sages and wise men, over periods of thousands of years. ... A land such as this is worth resuscitating. Once we have apprehended the true cause of its present desolate and abandoned condition, we are on our way to restoring it to its ancient fertility. A land which so readily responded to ancient science, and gave a return which sufficed for the maintenance of a Persian Court in all its splendor, will surely respond to the efforts of modern science and return manifold the money and talent spent on its regeneration.

WEATHER, n. The climate of an hour. A permanent topic of conversation among persons whom it does not interest, but who have inherited the tendency to chatter about it from naked arboreal ancestors whom it keenly concerned. The setting up of official weather bureaus and their maintenance in mendacity prove that even governments are accessible to suasion by the rude forefathers of the jungle.