Instead of a closed universe, science now presents us with one infinite in space and time, having no limits here or there, at this end, so to speak, or at that, and as infinitely complex in internal structure as it is infinite in extent. Hence it is also an open world, an infinitely variegated one, a world which in the old sense can hardly be called a universe at all; so multiplex and far-reaching that it cannot be summed up and grasped in any one formula. And change rather than fixity is now a measure of "reality" or energy of being; change is omnipresent. The laws in which the modern man of science is interested are laws of motion, of generation and consequence. He speaks of law where the ancients spoke of kind and essence, because what he wants is a correlation of changes, an ability to detect one change occurring in correspondence with another. He does not try to define and delimit something remaining constant in change. He tries to describe a constant order of change. And while the word "constant" appears in both statements, the meaning of the word is not the same. In one case, we are dealing with something constant in existence, physical or metaphysical; in the other case, with something constant in function and operation. One is a form of independent being; the other is a formula of description and calculation of interdependent changes.
In short, classic thought accepted a feudally arranged order of classes or kinds, each "holding" from a superior and in turn giving the rule of conduct and service to an inferior. This trait reflects and parallels most closely the social situation we were considering at the last hour. We have a fairly definite notion of society as organized upon the feudal basis. The family principle, the principle of kinship is strong, and especially is this true as we ascend in the social scale. At the lower end, individuals may be lost more or less in the mass. Since all are parts of the common herd, there is nothing especial to distinguish their birth. But among the privileged and ruling class the case is quite different. The tie of kinship at once marks a group off externally and gives it distinction, and internally holds all its members together. Kinship, kind, class, genus are synonymous terms, starting from social and concrete facts and going to the technical and abstract. For kinship is a sign of a common nature, of something universal and permanent running through all particular individuals, and giving them a real and objective unity. Because such and such persons are kin they are really, and not merely conventionally, marked off into a class having something unique about it. All contemporary members are bound into an objective unity which includes ancestors and descendants and excludes all who belong to another kin or kind. Assuredly this parcelling out of the world into separate kinds, each having its qualitatively distinct nature in contrast with other species, binding numerically distinct individuals together, and preventing their diversities from exceeding fixed bounds, may without exaggeration be called a projection of the family principle into the world at large.
In a feudally organized society, moreover, each kinship group or species occupies a definite place. It is marked by the possession of a specific rank higher or lower with respect to other grades. This position confers upon it certain privileges, enabling it to enforce certain claims upon those lower in the scale and entailing upon it certain services and homage to be rendered to superiors. The relationship of causation, so to speak, is up and down. Influence, power, proceeds from above to below; the activities of the inferior are performed with respect, quite literally, to what is above. Action and reaction are far from being equal and in opposite directions. All action is of one sort, of the nature of lordship, and proceeds from the higher to the lower. Reaction is of the nature of subjection and deference and proceeds from lower to higher. The classic theory of the constitution of the world corresponds point by point to this ordering of classes in a scale of dignity and power.
A third trait assigned by historians to feudalism is that the ordering of ranks centres about armed service and the relationship of armed defense and protection. I am afraid that what has already been said about the parallelism of ancient cosmology with social organization may seem a fanciful analogy; and if a comparison is also drawn in this last regard, there will be no doubt in your minds that a metaphor is being forced. Such is truly the case if we take the comparison too literally. But not so, if we confine our attention to the notion of rule and command implied in both. Attention has already been called to the meaning that is now given the term law—a constant relationship among changes. Nevertheless, we often hear about laws which "govern" events, and it often seems to be thought that phenomena would be utterly disorderly were there not laws to keep them in order. This way of thinking is a survival of reading social relationships into nature—not necessarily a feudal relationship, but the relation of ruler and ruled, sovereign and subject. Law is assimilated to a command or order. If the factor of personal will is eliminated (as it was in the best Greek thought) still the idea of law or universal is impregnated with the sense of a guiding and ruling influence exerted from above on what is naturally inferior to it. The universal governs as the end and model which the artisan has in mind "governs" his movements. The Middle Ages added to this Greek idea of control the idea of a command proceeding from a superior will; and hence thought of the operations of nature as if they were a fulfilment of a task set by one who had authority to direct action.
The traits of the picture of nature drawn by modern science fairly spring by contrast into high relief. Modern science took its first step when daring astronomers abolished the distinction of high, sublime and ideal forces operating in the heavens from lower and material forces actuating terrestrial events. The supposed heterogeneity of substances and forces between heaven and earth was denied. It was asserted that the same laws hold everywhere, that there is homogeneity of material and process everywhere throughout nature. The remote and esthetically sublime is to be scientifically described and explained in terms of homely familiar events and forces. The material of direct handling and observation is that of which we are surest; it is the better known. Until we can convert the grosser and more superficial observations of far-away things in the heavens into elements identical with those of things directly at hand, they remain blind and not understood. Instead of presenting superior worth, they present only problems. They are not means of enlightenment but challenges. The earth is not superior in rank to sun, moon and stars, but it is equal in dignity, and its occurrences give the key to the understanding of celestial existences. Being at hand, they are also capable of being brought under our hand; they can be manipulated, broken up, resolved into elements which can be managed, combined at will in old and new forms. The net result may be termed, I think, without any great forcing, the substitution of a democracy of individual facts equal in rank for the feudal system of an ordered gradation of general classes of unequal rank.
One important incident of the new science was the destruction of the idea that the earth is the centre of the universe. When the idea of a fixed centre went, there went with it the idea of a closed universe and a circumscribing heavenly boundary. To the Greek sense, just because its theory of knowing was dominated by esthetic considerations, the finite was the perfect. Literally, the finite was the finished, the ended, the completed, that with no ragged edges and unaccountable operations. The infinite or limitless was lacking in character just because it was in-finite. Being everything, it was nothing. It was unformed and chaotic, uncontrolled and unruly, the source of incalculable deviations and accidents. Our present feeling that associates infinity with boundless power, with capacity for expansion that knows no end, with the delight in a progress that has no external limit, would be incomprehensible were it not that interest has shifted from the esthetic to the practical; from interest in beholding a harmonious and complete scene to interest in transforming an inharmonious one. One has only to read the authors of the transition period, say Giordano Bruno, to realize what a pent-in, suffocating sensation they associated with a closed, finite world, and what a feeling of exhilaration, expansion and boundless possibility was aroused in them by the thought of a world infinite in stretch of space and time, and composed internally of infinitesimal infinitely numerous elements. That which the Greeks withdrew from with repulsion they welcomed with an intoxicated sense of adventure. The infinite meant, it was true, something forever untraversed even by thought, and hence something forever unknown—no matter how great attainment in learning. But this "forever unknown" instead of being chilling and repelling was now an inspiring challenge to ever-renewed inquiry, and an assurance of inexhaustible possibilities of progress.
The student of history knows well that the Greeks made great progress in the science of mechanics as well as of geometry. At first sight, it appears strange that with this advance in mechanics so little advance was made in the direction of modern science. The seeming paradox impels us to ask why it was that mechanics remained a separate science, why it was not used in description and explanation of natural phenomena after the manner of Galileo and Newton. The answer is found in the social parallelism already mentioned. Socially speaking, machines, tools, were devices employed by artisans. The science of mechanics had to do with the kind of things employed by human mechanics, and mechanics were base fellows. They were at the lower end of the social scale, and how could light on the heavens, the highest, be derived from them? The application of considerations of mechanics to natural phenomena would moreover have implied an interest in the practical control and utilization of phenomena which was totally incompatible with the importance attached to final causes as fixed determiners of nature. All the scientific reformers of the sixteenth and seventeenth centuries strikingly agree in regarding the doctrine of final causes as the cause of the failure of science. Why? Because this doctrine taught that the processes of nature are held in bondage to certain fixed ends which they must tend to realize. Nature was kept in leading strings; it was cramped down to production of a limited number of stereotyped results. Only a comparatively small number of things could be brought into being, and these few must be similar to the ends which similar cycles of change had effected in the past. The scope of inquiry and understanding was limited to the narrow round of processes eventuating in the fixed ends which the observed world offered to view. At best, invention and production of new results by use of machines and tools must be restricted to articles of transient dignity and bodily, not intellectual, use.
When the rigid clamp of fixed ends was taken off from nature, observation and imagination were emancipated, and experimental control for scientific and practical purposes enormously stimulated. Because natural processes were no longer restricted to a fixed number of immovable ends or results, anything might conceivably happen. It was only a question of what elements could be brought into juxtaposition so that they would work upon one another. Immediately, mechanics ceased to be a separate science and became an organ for attacking nature. The mechanics of the lever, wheel, pulley and inclined plane told accurately what happens when things in space are used to move one another during definite periods of time. The whole of nature became a scene of pushes and pulls, of cogs and levers, of motions of parts or elements to which the formulae of movements produced by well-known machines were directly applicable.
The banishing of ends and forms from the universe has seemed to many an ideal and spiritual impoverishment. When nature was regarded as a set of mechanical interactions, it apparently lost all meaning and purpose. Its glory departed. Elimination of differences of quality deprived it of beauty. Denial to nature of all inherent longings and aspiring tendencies toward ideal ends removed nature and natural science from contact with poetry, religion and divine things. There seemed to be left only a harsh, brutal despiritualized exhibition of mechanical forces. As a consequence, it has seemed to many philosophers that one of their chief problems was to reconcile the existence of this purely mechanical world with belief in objective rationality and purpose—to save life from a degrading materialism. Hence many sought to re-attain by way of an analysis of the process of knowing, or epistemology, that belief in the superiority of Ideal Being which had anciently been maintained on the basis of cosmology. But when it is recognized that the mechanical view is determined by the requirements of an experimental control of natural energies, this problem of reconciliation no longer vexes us. Fixed forms and ends, let us recall, mark fixed limits to change. Hence they make futile all human efforts to produce and regulate change except within narrow and unimportant limits. They paralyze constructive human inventions by a theory which condemns them in advance to failure. Human activity can conform only to ends already set by nature. It was not till ends were banished from nature that purposes became important as factors in human minds capable of reshaping existence. A natural world that does not subsist for the sake of realizing a fixed set of ends is relatively malleable and plastic; it may be used for this end or that. That nature can be known through the application of mechanical formulae is the prime condition of turning it to human account. Tools, machines are means to be utilized. Only when nature is regarded as mechanical, is systematic invention and construction of machines relevant to nature's activities. Nature is subdued to human purpose because it is no longer the slave of metaphysical and theological purpose.
Bergson has pointed out that man might well be called Homo Faber. He is distinguished as the tool-making animal. This has held good since man was man; but till nature was construed in mechanical terms, the making of tools with which to attack and transform nature was sporadic and accidental. Under such circumstances it would not have occurred even to a Bergson that man's tool-making capacity was so important and fundamental that it could be used to define him. The very things that make the nature of the mechanical-physical scientist esthetically blank and dull are the things which render nature amenable to human control. When qualities were subordinated to quantitative and mathematical relationships, color, music and form disappeared from the object of the scientist's inquiry as such. But the remaining properties of weight, extension, numerable velocity of movement and so on were just the qualities which lent themselves to the substitution of one thing for another, to the conversion of one form of energy into another; to the effecting of transformations. When chemical fertilizers can be used in place of animal manures, when improved grain and cattle can be purposefully bred from inferior animals and grasses, when mechanical energy can be converted into heat and electricity into mechanical energy, man gains power to manipulate nature. Most of all he gains power to frame new ends and aims and to proceed in regular system to their actualization. Only indefinite substitution and convertibility regardless of quality render nature manageable. The mechanization of nature is the condition of a practical and progressive idealism in action.