Popular Science Monthly/Volume 14/January 1879/Scientific Relation of Sociology to Biology I

From Wikisource
Jump to: navigation, search
Popular Science Monthly Volume 14 January 1879  (1879) 
Scientific Relation of Sociology to Biology I
By Joseph Le Conte


THE HIERARCHY OF SCIENCE.—There is a well-recognized scale in the hierachy of sciences. In the ascending order the steps are—mathematics, mechanics, physics, chemistry, biology, and geology. Mathematics deals only with space and time, number and quantity; and is therefore independent of matter and force. All other sciences deal also with matter and force, and are therefore properly called natural sciences, but they individually deal with different forms of matter and different grades of force. For example, the physical sciences deal only with those universal phenomena produced by physical forces; chemistry, in addition to these, deals also with a higher but more limited and special group of phenomena, determined by a peculiar force—chemical affinity; biology, in addition to all the preceding, deals also with a still higher and far more limited and special group of phenomena produced by a still more characteristic force—life.

The order of forces and phenomena-groups given above is, as we see, the order of increasing complexity and of increasing specialty, and therefore is also the order of their appearance in the evolution of the cosmos. There can be no doubt that physical forces and their associated phenomena appeared first, then chemical, then vital, and, lastly, rational (if these can be at all considered in the same category). It is also the order of dependence, and therefore, also, of historic development of the sciences based upon them. Mechanics is absolutely dependent on mathematics, and must, therefore, have awaited its development. Similarly, physics is dependent on both mathematics and mechanics, but especially the latter, and therefore must await its development. Similarly, chemistry must wait on all the preceding, but especially on physics; and biology must patiently await the development of all the preceding, but especially of chemistry.

But observe the following qualification: This is the necessary order in which these departments take on true scientific form, but not necessarily the order in which they are first commenced to be cultivated. Astronomy commenced to be cultivated by the Chaldeans long before mathematics or mechanics was sufficiently advanced to be applied to it. Biology commenced to be cultivated by Aristotle, or perhaps even by Solomon, long before chemistry and physics were sufficiently advanced to be of any use in biological investigations, add indeed before these sciences were born. In all sciences, but especially in the higher and more complex departments, there are three distinct stages of advance: The first consists in the observation, collection, and arrangement of facts—descriptive science. The second is the reduction of these to formal laws—formal science. Thus far the science is independent of other sciences. The third is the reference of these laws to the more general laws of a more fundamental science—in the hierarchy as their causecausal science. It is this last change only which necessarily follows the order indicated above. Its effect is always to give great impulse to scientific advance; for then only does it take on the highest scientific form, then only does it become one of the hierarchy of sciences, and receives the aid of all. Thus to illustrate: Tycho-Brahe laboriously gathered and collated a vast number of facts concerning planetary motions—descriptive astronomy. Kepler reduced these to the three great and beautiful laws known by his name—formal astronomy. But it was reserved for Newton, by means of the theory of gravitation, to explain the Keplerian laws by referring them to the more general and more fundamental laws of mechanics as their cause, and thus he became the founder of physical or causal astronomy. In other words, astronomy was first a separate science based on its own facts. Newton connected it with mechanics, and thus made it one of the hierarchy. From that time astronomy advanced with increased rapidity and certainty. Astronomy first rose as a beautiful shaft, unconnected and unsupported, except on its own pediment. In the meantime, however, another more solid and more central shaft had grown up under the busy hands of many builders, viz., mechanics. Newton connected the astronomical shaft with the central column of mechanics, and thus formed a more solid basis for a yet higher shaft. Characteristic Ideas.—Such, then, is the hierarchy of science and the mutual relations of the several orders. Now, each group of sciences, as Whewell has shown, has its own characteristic fundamental idea or ideas. For example, the fundamental ideas of mathematics—the ideas underlying all its operations—are those of number and quantity. The fundamental idea of mechanical and physical sciences is that of physical force. The fundamental idea peculiar to chemistry and underlying all its distinctive phenomena is that of affinity. The fundamental idea underlying all the distinctive phenomena of biology is that of life. Subordinate ideas under these general heads we shall call, after Comte, doctrines.

Characteristic Methods.—Again, each group of sciences has also its characteristic method. The characteristic method of mathematics is that of notation. We are all familiar with the wonderful power of this method. By the use of a few figures, viz., the numeral digits, having each a value of its own and another depending on position, a few symbols, a and b, x and y, connected by signs, + and—and =, the veriest schoolboy may quickly solve problems which would defy the unassisted efforts of the greatest genius. The characteristic method of physics and chemistry is experiment: without the use of this potent instrument these sciences could not advance a step. The characteristic method of biological sciences is the method of comparison. The use of this method we will illustrate after a while.

Now, each group, after it once enters the hierarchy, besides its own characteristic ideas and methods, uses freely and with the greatest advantage all the ideas and methods of the lower sciences, but especially those of the science immediately below, and with which, therefore, it is immediately connected. Thus chemistry uses the characteristic ideas and methods of physics and mathematics, but especially of physics. Biology, besides its own characteristic ideas and methods, uses freely the methods and ideas of chemistry—physics and mathematics—but especially those of chemistry. If there be any other still higher science, it must use with the greatest advantage the ideas and methods of all lower sciences, but especially those of biology.

Again: although the ideas and methods of the lower groups are imported into the higher groups and freely used there, yet we acquire clear conceptions of such ideas and doctrines, and expertness in the use of such methods, only in the group where they are native and characteristic. Thus, each group of sciences becomes the appropriate school for its own characteristic doctrines and methods. For example, physics uses freely the method of notation, but mathematics is the true school of this method. Biology uses experiment, but physics is the true school of this method. If there be any other still higher science which shall use the doctrines of life and the method of comparison, the cultivators of that science should first acquire clear conceptions of these doctrines, and learn expertness in the use of this method by the previous study of biology.

Now, there is, or shortly will be (for it is scarcely yet organized), a science far higher than any yet mentioned—a science which is the crown of human knowledge—a science to which all others are subsidiary—sociology. I wish to show the close connection between this science and biology. I wish to show that it only becomes truly scientific by being connected with biology, and thus placed at the head of the hierarchy. I wish to show that whatever of recent advance has been made in this science has been made by the application of the characteristic doctrines and methods of biology. I wish to show that biology is an important—yea, more, the most important—preparatory school for the study of sociology.

Biological Ideas applicable to Sociology.—As already stated, the fundamental idea of biology is life. Under this general idea there are two subordinate ideas or doctrines, viz., organization and progress by evolution. Life is maintained through an organized structure. Life advances from lower to higher grades by evolution. Now, is not society, too, endowed with life? Is not the social life maintained by organization; and does it not advance from lower to higher grades by a process of evolution? Let us examine in more detail:

1. Organization.—A living organized structure, or an organism, may be defined as a structure consisting of many different parts, having different forms, and performing different functions, but all coöperating to one given end, viz., the life, growth, and development, of the whole. The animal organism is composed wholly of cells, as a building is of bricks; all animal functions are performed by cells; growth is continual formation of new cells; reproduction is the separation of cells to form a new colony of cells. But the constituent cells of an organism, especially one of the higher organisms, are not all alike. On the contrary, they are as diverse in form as they are in function. The many functions of the body are parceled out among the cells by division of labor, and thus there results an absolute mutual dependence of parts. So society, also, is composed of many structural elements (individuals), having different pursuits, i. e., performing different social functions, and therefore mutually dependent, but all cooperating to maintain the life of the whole. Society, therefore, is in some sense an organism and subject to the laws of life and organization.

Again, as in the animal organism, the structural elements, the cells, are far more numerous than the functions: many cells of similar form aggregate to form organs, all the cells of one organ coöperating to perform its function, and all the organs cooperating for the life of the whole organism. So in the social organism, the structural elements (individuals) being much more numerous than the social functions, many individuals of like pursuits or functions aggregate into corporations, professions, trades-unions, etc. These are the organs of the social body. They ought to coöperate for the welfare of the whole,

2. Evolution.—All the laws of evolution which have been discovered in organisms apply also to society, but with certain limitations, which I believe are very significant.

(a.) Law of Differentiation.—The most fundamental law of evolution is differentiation. The organism, as I have described it above, with its cells of diverse forms and functions, was not thus constituted in the beginning of its existence, but gradually became so by a process of differentiation. In the early stages of an organism the constituent cells are all alike in form, and each performs, though imperfectly, all the functions necessary in this early stage. But, as the organism develops, the cells begin to take on different forms, and to perform different functions, and this process of differentiation continues until, in the mature condition of the highest organisms, each group of cells (or each organ) is limited to the performance of one function only. This one function is its only evidence of life. Now, concurrently with this increasing differentiation of form and limitation of function, there is, of necessity, an increasing mutual dependence of parts, and a sacrifice of the independent life of the part to the common life of the whole. In the lowest condition of the organism, where the cells are all alike, and each performs, though imperfectly, all the functions, there is a very considerable, sometimes a complete, independent life in each cell; so that it may be separated without injury either to itself or to the community of cells: the independent life is large, the common life is feeble. But, as we rise in the scale of organization, the independent life of the part is merged more and more into the general life of the whole—is sacrificed, and goes to make up the common life—until, in the mature condition of the highest organisms, the independent life of the constituents is reduced to a minimum, while the common life is advanced to a maximum. This complete merging of the independent life of the part into the common life—this identification of life with function—is the ideal of the animal organism: the nearer it approaches this condition the higher manifestly is the organism.

Or take instead that larger organism, more nearly resembling, and therefore better illustrating, the social organism, viz., the whole organic kingdom,its present diverse condition has been reached also only by a process of differentiation. Commencing in the earliest times, with similar and independent beings, by a continual process of separation and differentiation, animal forms have become more and more diverse, occupying different places and performing different functions in the economy of Nature; the higher becoming still higher, and the lower becoming lower; the mutual dependence and interaction of all parts becoming greater and greater, until the ideal seems almost reached in the present fauna and flora. If we can conceive any organism still higher than man, or lower than the monera—if we can conceive a relation and interaction between the different kinds constituting a fauna and flora still more complex, and a struggle for life still fiercer than now exists, then is the ideal not yet reached.

So society, also, has reached its present highly-organized condition only gradually, by a process of differentiation. In the early stages of society the constituent elements are all alike, and each performs, though in an imperfect manner, all the social functions necessary in this early condition. As society advances, the pursuits of man become more and more different, the social function of each more and more limited, until each is confined to one social function only. Concurrently with this differentiation of pursuits, the independent life of the constituents, absolutely perfect at first, is merged more and more into the common life of society, with increasing mutual dependence, as in the animal organism; and yet, alas! with increasing selfish antagonism and competitive struggle for life, as in the organic kingdom. Here, too, from the purely material point of view, the ideal, as in the animal organism, is complete loss of independent life—the complete merging of the individual independence into the common life of society—the identification of individual life with social function. Here, too, from the same point of view, the ideal, as in the organic kingdom, is the highest high and the lowest low, and the extremest diversity. The higher becomes the high, the lower sinks the low, and the more extreme the diversity—the more complete the loss of individuality and merging of constituent life into social function—the more perfect the mutual dependence, and yet the fiercer the antagonism and struggle—the nearer do we approach the ideal. This is manifestly the ideal of material organization, and therefore of society, from a purely material point of view. If this ideal is not only undesirable but impossible—if our whole better nature shrinks aghast from its realization—it is because it takes no cognizance of our higher and distinctively human nature, i. e., our spiritual or moral nature; it is because the law of our spiritual or moral is different and even antagonistic to the law of our animal or material nature. The relation of material units is by mutual dependence, and yet antagonism: the relation of moral units is by mutual sympathy and love. The existence of a moral nature limits the laws of a purely material organization. The essential difference, therefore, between the animal organism and the social organism is that, in the former, the constituents exist only for the community, while in the latter the community exists only for the constituents. This transcendent value of the constituents is manifestly the result wholly of the moral or spiritual nature of man.

There are, then, three stages of social advance: 1. Gregariousness, or loose, unorganized association of similar constituents: this corresponds in biology to the simplest form of cellular aggregation. 2. Gradually increasing differentiation and consequent merging of the constituent life into the common life by limitation of function, and therefore mutual physical dependence, until the constituent life is finally identified with the social function: this corresponds with the ideal of material organization. 3. The reassertion of the independent personality of the constituents, and the alliance of these by moral instead of physical bonds—by mutual love instead of mutual dependence: this has no correspondence in material organization, since it becomes possible only through a higher nature than the material. There are, therefore, two modes of subordinating the individual life to the race—one by mutual dependence, the other by mutual love. The former destroys our personality, the second enhances it. He who loses his independent life by the first method, loses it irretrievably; he who loses it by the second method, shall find it again. The former is the ideal of material organization, and has been partially attained in many forms of society, ancient and modern; the latter is the ideal of Christian civilization. Society is even now in a state of transition between the two.

(b.) Progress.—The more fundamental law of differentiation limits, and in the minds of many persons confuses, the idea of progress. Progress as a law of evolution does not imply advance to successively higher points along every line and in every part; but only that the highest parts become successively higher, and the whole becomes successively greater. The constituent parts of a developing organism, starting from a common level, are some of them advanced to the dignity of brain-cells, and become the instruments of thought, while others sink to the condition of kidney-cells, whose function is only to secrete urine. But the highest cells become higher and higher, and the whole organism becomes greater and more complex.

Again, in the development of the organic kingdom, from the earliest geological times until now, if we could trace the several lines of genetic descent, we would doubtless find as many examples of retrograde as of advance movement. This fact has given rise to most of the dispute concerning the existence or non-existence of a law of evolution in the organic kingdom. This dispute is mostly the result of a misapprehension of the law of evolution. In the process of differentiation of the organic kingdom from a common level, the lines of descent went some upward, some downward, some sideways, every way and any way to reach some unoccupied place and subserve some different function in the economy of Nature, but the dominant classes became successively higher, and the whole organic kingdom successively greater and more highly organized. The tree of life sent its branches, some upward, some sideways, some downward, any way and every way for room and light, but its top went higher and ever higher, and its whole clustering branches became broader and ever broader.

So is it in society: if we could trace all the lines of genetic descent, starting from a common level, some would go upward, some downward, some this way and some that; in social function some would advance to the dignity of philosophic thinkers—the teachers of the race—and some would sink to street-sweepers and sewer-cleansers. But the highest went progressively higher, and the whole became progressively grander. We are saved from the real as well as apparent degradation of these lower functionaries, only by the fact that the constituents cannot in the social organism, as they can in the material organism, be identified with and merged into their functions. Man has, fortunately, many other functions besides his social functions, viz., those higher functions connected with his moral nature.

In all progress, therefore, and as a necessary consequence of the law of differentiation, there is a straight and very narrow way, from the lowest to the highest, or ideal. Thus, in the progress of the organic kingdom from the lowest eozoön to the final term, the ideal, of material evolution—man—there is only one straight and narrow way onward and upward. Any turning off from that way leads, perhaps, to some other excellence, but not toward the highest—not toward man. Once leave the straight way, and there is no getting back upon it. Progress goes on, but only on the path chosen. The law, so far as material evolution is concerned, is inexorable. The tree of evolution has but one straight, ascending trunk leading upward to its terminal bud. A growing-point, once separated as a branch, continues, indeed, to grow, but only on its own way.

The same is true of higher forms of evolution. The progress of evolution of the organic kingdom, completed in man, is immediately taken up by man and carried forward on a higher plane in social evolution; and here, again, we find the same law. In the progress from primitive man to the condition of the most cultured races, there has been but one straight and narrow way. Those nations who by differentiation turned off from that track, have gone each their separate way—some this, some that—but cannot get back, or have not yet got back, on the true line of progress toward the highest. I do not say, however, that it is impossible to get back, for Reason again comes in to modify the material law and to confer plasticity on the nature of man.

The same law, again, appears epitomized with terrible significance in the history of each individual human soul. In the progress of the human spirit from childhood to the highest ideal of intellectual and moral culture—the Christian ideal—there is the same straight and narrow way. If we turn off from that way, it is easy to go on, but alas! how hard to get back! But for the modification of material laws by the presence of a higher law, it would be impossible.

(e.) Cyclical Movement.—In all evolution the progress which we have illustrated under the last head advances not at uniform rate, but in a succession of cycles by the rise, culmination, and decline, of higher and still higher dominant functions, principles, ideas, etc. Thus, in the individual human organism, there rise, culminate, and decline, first in childhood the nutritive functions; then in youth and early manhood, the reproductive and muscular functions; and, lastly, in full maturity, the cerebral functions. Or, in the development of the mind, there rise, culminate, and decline, first in childhood, the perceptive faculties and the memory; then in youth and young manhood, the imaginative and æsthetic faculties; then in full manhood, or even beyond, the faculty of productive thought; and, finally, only late in life, and if the life has been noble, the moral and religious nature: the first, gathering and storing the materials for intellectual growth; the second, warming, vivifying, vitalizing, the materials thus gathered; the third, using them in constructive mason-work—in building the temple of science and philosophy; the last beautifying and ennobling that temple and dedicating it to holy purposes, thus connecting the evolution of the spirit in this life with that which, as we hope, continues in another. Similarly, in the development of that greater organism, viz., the organic kingdom, we have the rise, culmination, and decline of successively higher and higher classes of organisms: first of mollusca, then of fishes, then of amphibia, then of reptiles, then of mammals, and, finally, of man. And here, too, in the last step we find again the lower or animal evolution connected with and continued by a higher, viz., the social evolution.

So is it also in society. Here, too, we find progress is accomplished by a successive rise, culmination, and decline, of higher and higher dominant ideas or principles, determining different phases of civilization. The law may be traced not only in the general civilization of successive epochs, but even in the component parts or principles of civilization. It is not only cycle beyond and above cycle, but also cycle within cycle. Thus we have successively culminating and declining Egyptian, Greek, Roman, and now rising but not yet culminating, modern civilization, confessed by higher and higher forms. In natural religion we have everywhere first fetichism, then polytheism, and then monotheism. In the direct line of modern religious organization we have the Jewish and the Christian form. In the Christian Church we have the primitive or apostolic form, the Roman form, the Protestant forms, and we yet hope for a still higher and more rational form in the future.

But, observe: in all development, when a dominant function, faculty, principle, etc., declines, it does not perish, but only becomes subordinate to the next rising and higher dominant function or principle, and thus the whole organism becomes not only higher but also more complex. Thus, when the perceptive faculties and memory decline in early manhood, they do not perish, but only become subordinate to the higher dominant imaginative and æsthetic faculties characteristic of that age. Again, when these latter decline they do not perish, but only in their turn become subordinate to the still higher faculty of productive thought, which in its turn, and with it the whole character, becomes subordinate to the moral and religious nature. Thus the perfect man does not forget utterly the things of childhood and youth and early manhood, but incorporates all that is best in each, and subordinates them to the highest; and thus the whole character becomes broader and more universal in its sympathies, as well as higher. This is the true type of culture—for culture is naught else than a natural evolution assisted by art. True culture does not educate us out of sympathy with childhood and youth, nor above sympathy with the lower classes of society; it does not simply raise us pygmies on a platform above the heads of our fellow-men, but without increasing our stature. If our culture does so, it is a false culture. The true cultured man stands on the same common level with other men, only his higher parts rise higher. But see the necessity which this law lays upon us of never-ceasing culture! Beautiful, joyous childhood cannot last, must decline. If we do not cultivate the higher imaginative and æsthetic faculties, our nature inevitably deteriorates from that time. Glorious youth and young manhood must decline, and with it our whole nature must deteriorate if we do not cultivate reflective and productive thought. Lofty intellectual power must also decline. Alas! how sad to see in old age the whole character deteriorate for want of moral and religious culture, which alone insures immortal progress!

The same law holds equally in the development of the organic kingdom. When the class of fishes declined in power, it did not perish, but became subordinate to the incoming higher dominant class of reptiles, which, in its turn, sought safety in subordination to the still higher incoming class of mammals, and this in its turn to the highest dominant class, man; and thus the whole organic kingdom becomes not only higher, but also broader, more complex, more diverse.

So, also, in society. When any dominant idea, principle, or social force of any kind, characteristic of any phase of civilization, declines, it does not perish, but becomes incorporated into the next higher phase of civilization as a subordinate force or principle. Thus each age incorporates what is best in the previous age, and modern society is the resultant of all the social forces which have acted from the beginning—is the heir of all the ages; and the social organism has thus become not only higher, but broader, stronger, and more complex. And here, again, the same necessity is laid upon us, of continuous progress or else of decline. No mere phase of civilization can last, no social force can continue in its pristine power. That nation which refuses to accept the incoming principle is left behind and inevitably decays.

Observe again: the speediness of the rise, culmination, and decline—the short-livedness—of any phase of civilization is in proportion to the limited character of the principles involved—the partialness of the embodiment of all the principles of our humanity. As society becomes more complex, its cycles become longer, until it reaches continuous, steady progress—immortality—only in the complete embodiment of an ideal humanity. Such we believe is the ideal of a Christian civilization.

Observe again: in all forms of development the culmination and decline are in strength rather than in quality. This is only another mode of expressing subordination to a higher force. The perceptive and imaginative faculties, indeed, decline in strength and vigor as age advances; but they steadily progress in refinement, if intellectual culture continues. If, for example, relish for art is more intense in youth, it is also more gross. If it declines with age, it becomes also more refined, more discriminating, higher—i. e., it becomes subordinated to higher faculties. The same is true of development of the organic kingdom; for, when a dominant class declines, it declines in strength, not in organization. So, also, is it in society. The principle of chivalry, for example, culminated in the middle ages. It has since declined in strength, but gained in refinement; lost in quantity, but gained in quality. It has become less fantastic, less extravagant, less affected; more rational and genuine. In other words, it has become subordinated to still higher principles.

Observe again and finally: this idea of progress of society by cyclical movement is comparatively modern, and even yet imperfectly apprehended. Whence did it come? We see no evidence of it among the ancient Egyptians, Greeks, or Romans, nor among modern Chinese or Japanese. None of these could conceive any civilization higher than their own. None of these dreamed of an onward progress of the whole race, of which their own civilization was only one temporary phase. The Jews had it not. They could not conceive of their religion and polity passing away. Is it to be wondered at, therefore, that they rejected Christ, who preached the unheard-of doctrine of the introduction of a new era? The idea was, in fact, first announced by Christ himself, when he taught that the Jewish polity and ritual must pass away, and yet the law he fulfilled; that the form is temporary, but the spirit eternal; that the form dies, but the spirit must take on higher and higher forms. Until that time it is doubtful if the idea of any scheme of religion or politics being a temporary phase of civilization, and therefore passing away by the very law of human progress—the idea that the forms of the social body like the forms of the animal body are necessarily temporary—ever entered the human mind. How imperfectly it is yet apprehended, even by the most advanced peoples, is plainly shown by the history of both church and state. Immutable forms have ever been asserted and maintained by force until violently broken and thrown off by revolution. This great law is now generalized and made a universal law of all evolution only by biological research.

(d.) Survival of the Fittest.—The survival of the fittest, in the fierce struggle for life, is the best known and most universally recognized factor of the evolution of the organic kingdom. The manner in which this factor operates especially in successive differentiation, and the increasing specialization of each differentiated form, in causing the tree of life to branch and again branch continuously, each branch pushing its shoot as far as possible in its own direction, are well understood. The gradual but steady improvement, the strengthening of the blood, increasing the energies, sharpening the instincts by ruthless destruction of the weak, the slow, the dull, the unfit in any way, and thus adapting the remaining strong and active in the most perfect manner to the various and varying conditions of life, is also clear. This pitiless principle acts among animals without limit except in the case of the young of the higher animals, and its good effect is just in proportion to its pitilessness.

Now, in human society, also, the same principle must act and does act as a powerful agent of progress, but not without limit. There is here introduced a higher moral or spiritual law which limits and modifies the operation of the material law inherited from the animal kingdom—a law which seeks the survival and improvement of all. As animality gradually developed into humanity (if we accept this view), this new principle of benevolence and mutual help was added to the old principle of selfism and mutual antagonism inherited with the animal nature. A new principle of altruism (as it is now fashionable to call it) was added to the old principle of egoism, in small proportions at first, but gradually increasing in strength as humanity' is developed. Under the influence of the Christian ideal this principle has become so active in modern society as to seriously impair the healthy operation of the more fundamental principle of the struggle for life. There is little doubt that the survival of the weak and helpless, and the sustentation of the unfit and the vicious, are beginning to poison the blood and paralyze the energy of the race. Also the survival of so many who would be eliminated by the operation of the old principle, increases the pressure of population on the means of subsistence, and thus also increases the evil. How shall we, then, settle the claims of these two opposite principles—the one necessary to the physical, the other to the moral improvement of the race? It is evident that Reason must hold the balance, adjust the equilibrium, and repair any damage which has already resulted. This she will eventually do by pointing out and enforcing simpler and more rational modes of life, by sanitary regulations, and by proper physical education. Thus will it gradually restore and increase the vigor of the race. It will undoubtedly also prevent the pressure of increasing population upon the means of subsistence by limiting reproduction by rational, healthy, and moral methods. I call special attention to this as another example of the limitation or even reversal of a purely material law by a higher law connected with our spiritual nature.

  1. The views here presented were first embodied in the form of a lecture in 1859, and published in the Southern Presbyterian Review in April, 1860. They are now rewritten and condensed, the order of presentation entirely changed, and some new thoughts added. I mention this only to show that they are largely the result of independent thought—for they antedate the recent literature on the subject of sociology, as also Darwin's work on "Origin of Species." This representation has been affected by Darwin's work only in one point, viz., the introduction of the principle of survival of the fittest. To two authors only I acknowledge large indebtedness. To Comte I am indebted for the general idea of a scientific connection between sociology and biology. To Agassiz I am indebted for a clear conception of the characteristic doctrines and methods of biology. In fact, all the formal laws of evolution, as now recognized, were announced by him, although he did not accept the origin of species by derivation. For the application of these laws to sociology, and for the mode of presentation, I am alone responsible.