§ [47]. But science tends to employ for these systems only such conceptions as relate to prediction; and of these the most fundamental are space and time. The first science to establish its method was the science of astronomy, where measurement and computation in terms of space and time were the most obvious means of description; and the general application of the method of astronomy by Galileo and Newton, or the development of mechanics, is the most important factor in the establishment of modern science upon a permanent working basis. The persistence of the term cause, testifies to the fact that science is primarily concerned with the determination of events. Its definitions of objects are means of identification, while its laws are dynamical, i. e., have reference to the conditions under which these objects arise. Thus the chemist may know less about the properties of water than the poet; but he is preëminently skilled in its production from elements, and understands similarly the compounds into which it may enter. Now the general conditions of all anticipation, whereby it becomes exact and verifiable, are spacial and temporal. A predictable event must be assigned to what is here now, or there now; or what is here then, or there then. An experimentally verifiable system must contain space-time variables, for which can be substituted the here and now of the experimenter's immediate experience. Hence science deals primarily with calculable places and moments. The mechanical theory of nature owes its success to a union of space and time through its conceptions of matter and motion.[132:4] And the projected theory of energetics must satisfy the same conditions.
The Quantitative Method.
§ [48]. But, furthermore, science has, as we have seen, an interest in freeing its descriptions from the peculiar angle and relativity of an individual's experience, for the sake of affording him knowledge of that with which he must meet. Science enlightens the will by acquainting it with that which takes place in spite of it, and for which it must hold itself in readiness. To this end the individual benefits himself in so far as he eliminates himself from the objects which he investigates. His knowledge is useful in so far as it is valid for his own indefinitely varying stand-points, and those of other wills recognized by him in his practical relations. But in attempting to describe objects in terms other than those of a specific experience, science is compelled to describe them in terms of one another. For this purpose the quantitative method is peculiarly serviceable. With its aid objects permit themselves to be described as multiples of one another, and as occupying positions in relation to one another. When all objects are described strictly in terms of one another, they are expressed in terms of arbitrary units, and located in terms of arbitrary spacial or temporal axes of reference. Thus there arises the universe of the scientific imagination, a vast complexity of material displacements and transformations, without color, music, pleasure, or any of all that rich variety of qualities that the least of human experiences contains. It does not completely rationalize or even completely describe such experiences, but formulates their succession. To this end they are reduced to terms that correspond to no specific experience, and for this very reason may be translated again into all definable hypothetical experiences. The solar system for astronomy is not a bird's-eye view of elliptical orbits, with the planets and satellites in definite phases. Nor is it this group of objects from any such point of view, or from any number of such points of view; but a formulation of their motions that will serve as the key to an infinite number of their appearances. Or, consider the picture of the ichthysauria romping in the mesozoic sea, that commonly accompanies a text-book of geology. Any such picture, and all such pictures, with their coloring and their temporal and spacial perspective, are imaginary. No such special and exclusive manifolds can be defined as having been then and there realized. But we have a geological knowledge of this period, that fulfils the formal demands of natural science, in so far as we can construct this and countless other specific experiences with reference to it.
The General Development of Science.
§ [49]. Science, then, is to be understood as springing from the practical necessity of anticipating the environment. This anticipation appears first as congenital or acquired reactions on the part of the organism. Such reactions imply a fixed coördination or system in the environment whereby a given circumstance determines other circumstances; and science proper arises as the formulation of such systems. The requirement that they shall apply to the phenomena that confront the will, determines their spacial, temporal, and quantitative form. The progress of science is marked by the growth of these conceptions in the direction of comprehensiveness on the one hand, and of refinement and delicacy on the other. Man lives in an environment that is growing at the same time richer and more extended, but with a compensatory simplification in the ever closer systematization of scientific conceptions under the form of the order of nature.
The Determination of the Limits of Natural Science.
§ [50]. At the opening of this chapter it was maintained that it is a function of philosophy to criticise science through its generating problem, or its self-imposed task viewed as determining its province and selecting its categories. The above account of the origin and method of science must suffice as a definition of its generating problem, and afford the basis of our answer to the question of its limits. Enough has been said to make it clear that philosophy is not in the field of science, and is therefore not entitled to contest its result in detail or even to take sides within the province of its special problems. Furthermore, philosophy should not aim to restrain science by the imposition of external barriers. Whatever may be said of the sufficiency of its categories in any region of the world, that body of truth of which mathematics, mechanics, and physics are the foundations, must be regarded as a whole that tends to be all-comprehensive in its own terms. There remains for philosophy, then, the critical examination of these terms, and the appraisal as a whole of the truth that they may express.
Natural Science is Abstract.
§ [51]. The impossibility of embracing the whole of knowledge within natural science is due to the fact that the latter is abstract. This follows from the fact that natural science is governed by a selective interest. The formulation of definitions and laws in exclusively mechanical terms is not due to the exhaustive or even preëminent reality of these properties, but to their peculiar serviceableness in a verifiable description of events. Natural science does not affirm that reality is essentially constituted of matter, or essentially characterized by motion; but is interested in the mechanical aspect of reality, and describes it quite regardless of other evident aspects and without meaning to prejudice them. It is unfortunately true that the scientist has rarely been clear in his own mind on this point. It is only recently that he has partially freed himself from the habit of construing his terms as final and exhaustive.[137:5] This he was able to do even to his own satisfaction, only by allowing loose rein to the imagination. Consider the example of the atomic theory. In order to describe such occurrences as chemical combination, or changes in volume and density, the scientist has employed as a unit the least particle, physically indivisible and qualitatively homogeneous. Look for the atom in the body of science, and you will find it in physical laws governing expansion and contraction, and in chemical formulas. There the real responsibility of science ends. But whether through the need of popular exposition, or the undisciplined imagination of the investigator himself, atoms have figured in the history of thought as round corpuscles of a grayish hue scurrying hither and thither, and armed with special appliances wherewith to lock in molecular embrace. Although this is nonsense, we need not on that account conclude that there are no atoms. There are atoms in precisely the sense intended by scientific law, in that the formulas computed with the aid of this concept are true of certain natural processes. The conception of ether furnishes a similar case. Science is not responsible for the notion of a quivering gelatinous substance pervading space, but only for certain laws that, e. g., describe the velocity of light in terms of the vibration. It is true that there is such a thing as ether, not as gratuitously rounded out by the imagination, with various attributes of immediate experience, but just in so far as this concept is employed in verified descriptions of radiation, magnetism, or electricity. Strictly speaking science asserts nothing about the existence of ether, but only about the behavior, e. g., of light. If true descriptions of this and other phenomena are reached by employing units of wave propagation in an elastic medium, then ether is proved to exist in precisely the same sense that linear feet are proved to exist, if it be admitted that there are 90,000,000 × 5,280 of them between the earth and the sun. And to imagine in the one case a jelly with all the qualities of texture, color, and the like, that an individual object of sense would possess, is much the same as in the other to imagine the heavens filled with foot-rules and tape-measures. There is but one safe procedure in dealing with scientific concepts: to regard them as true so far as they describe, and no whit further. To supplement the strict meaning which has been verified and is contained in the formularies of science, with such vague predicates as will suffice to make entities of them, is mere ineptness and confusion of thought. And it is only such a supplementation that obscures their abstractness. For a mechanical description of things, true as it doubtless is, is even more indubitably incomplete.
The Meaning of Abstractness in Truth.