increase of heat as analogous to the regaining of its original potential energy.1 If the analogy held this would mean that in the new system the sum of kinetic energy and heat would be a constant; or that the amount of heat replacing the lost kinetic energy would in turn yield the same amount of kinetic energy. And experiment has proved this to be the case. Similarly, it has been discovered that kinetic energy can be reciprocally and conservatively converted into light, electricity, etc. When thus expressed, energy, like mass, is a ratio. It means that, despite the appearance of bare disjunction when motion gives place to heat, or heat to light, etc., there is a certain permanence of relations. The amount of motion, heat, light, etc., is the same in a certain specific respect; in the respect, namely, that when one is converted into another, the sum of the two remains the same, and the amount of the second is such as to be again convertible into the same amount of the first. This may be expressed otherwise by saying that when such a qualitative change takes place, that which is apparently lost is in a certain sense conserved, in that it exists potentially in the new quality. Thus energy, like acceleration, mass, and the rest, is a constant relationship or proportion of variable terms. And as in the case of the other concepts, so here also, the terms are functions of space and time, or of properties that occupy them; and the relationship or proportion is exact and mathematical. § 10. Such is the meaning of certain typical scientific concepts, or descriptive formulas, so far as can be gathered from a direct examination of them in relation to the subject-matter which they are intended Scientific Con- to describe. There is a question which I am sure will occur to many readers as proper The Analytical cepts 1 It is not necessary to suppose that heat, electricity, etc., are mechanical, in the strict sense, i.e., constituted of internal motions. "Nothing is contained in the expression," says Mach, “but the fact of an invariable quantitative connexion between mechanical and other kinds of phenomena." Cf. Principles of Mechanics, p. 499. and necessary to raise; the question, namely "What really is mass or energy?" Upon the legitimacy of this question turns the issue between naïve and critical naturalism, with which we shall be occupied in the next chapter. The question is evidently meant to convey the idea that mass and energy cannot be merely ratios or formulas that they must be things, in some more reputable sense. But if such be the case, at any rate it does not appear in the exact records of science. There may be an antecedent play of the imagination or a speculative after-thought, in which mass is a simple substance and energy a simple activity. But as exactly formulated, and experimentally verified, mass and energy are mathematical relationships. And if this analytical version of scientific concepts will suffice in the case of the simpler concepts, there is no reason why it should not suffice also in the case of the more complex concepts. When motion is described it turns out to be a definite relation to space and time, of something which occupies them jointly. Such an account of motion is not imposed upon it by any subjective predilection for a relational technique. It is empirically characteristic of a moving body to be now here, now there, and for every intermediate instant to occupy an intermediate point. The calculus of motion is merely the most faithful account of it which the mind has been able to render. The same is true of the more complex thing called velocity. It is the ratio of the distance factor and the time factor in the case of a moving body. When we pass from velocity to acceleration, mass, gravitation, and even to energy, we are simply observing and recording more complicated aspects of a moving or otherwise changing body. The analytical version of these concepts corresponds to the specfic complexity on which observation has seized. The supposition that there must be a real mass or energy other than the analytical complex, betrays the influence of words. Because 'mass' is one word like 1 This supposition is also due in part to a projection of the feeling of effort into bodies which act as efficient causes. Cf. below, p. 70. 'blue,' it is felt that it must be one indivisible thing like blue. But it would be as reasonable to say that motion is an indivisible thing because the word 'motion' is single; whereas it is evident that motion contains both space and time, and is therefore complex. I am led to conclude, therefore, that all of these concepts are essentially ratios or relational complexes of the simple terms of experience, such as space, time, color, sound, etc.; and that each of these ratios or relational complexes expresses some specific complexity or configuration, which is found in nature. And I judge that these concepts illustrate the motive of science; which is simply to describe and record, with special reference to their unity and constancy, the actual changes of bodies. The Two Varieties of CHAPTER IV NAÏVE AND CRITICAL NATURALISM § 1. NATURALISM, as we have seen, is not science, but an assertion about science. More specifically, it is the assertion that scientific knowledge is final, leaving no room for extra-scientific or philoNaturalism sophical knowledge. Naturalism assumes two forms. On the one hand there is a variety of naturalism which adopts the traditional problems, and to a large extent the traditional methods, of philosophy. It continues, e.g., the philosophical search for a universal substance and a first cause, and claims to have discovered these in some such scientific concept as 'matter' or 'force.' The second variety of naturalism repudiates not only the solutions of the traditional philosophy, but the problems and methods as well. It condemns the search for universal substance and first cause as futile. Its last word is a theory of knowledge, in which science is asserted to be final because the only case of exact knowledge. In other words, the second variety of naturalism claims less for the concepts of a science, but nevertheless claims all. Science is not the only knowledge that has been dreamed of, but it is the only knowledge that is possible. The first variety of naturalism is metaphysical, the second proclaims its 'anti-metaphysical' character. Or the first may be called 'materialism,' and the second 'positivism.' The crucial difference between these two forms of naturalism is to be found, I think, in what they make of scientific concepts. The first construes matter, mass, energy, and the rest, as simple substances or powers. Owing to its failure to analyze these concepts, owing to its uncritical assumption that whatever has a single name must be an indivisible thing, I propose to call this 'naïve naturalism.' The second variety, on the other hand, accepts the analytical version of scientific concepts, as set forth in the last chapter, and hence may be called 'critical naturalism.' Naïve naturalism, metaphysical naturalism, or materialism, derives its form from philosophy — and its defects as well. Indeed it affords the best example available of the characteristic defects of philosophy, of those errors to which philosophy is perpetually and peculiarly liable owing to the motives which rule it. We shall, therefore, be aided both in the exposition and in the criticism of naïve naturalism if we have certain of these errors clearly in mind. Three Charac teristic Philo § 2. In the first place, there is an error to which I propose to give the name of 'the speculative dogma." By this I mean the arbitrary assertion of the ideal of thought. What that ideal is, when verbally sophical Errors. formulated, may be inferred from our review "The Specula- of the procedure of science. The concepts of tive Dogma' science satisfy thought's peculiar bias for identity and permanence. Thought seeks so far as possible to construe particulars as modes of the general, to construe what is apparently unique as a special instance of something that is common. It seeks also to account for as much as possible of any individual phenomenon, in terms of such a general concept. It seeks concepts, in short, that shall be both general, and also sufficient or adequate, to the things subsumed under them. Now philosophy has especially to do with ultimates and finalities. So the philosophical form of this general propensity of thought gives rise to the ideal of a concept that shall be of unlimited generality and sufficiency. The concepts of acceleration and mass make possible the systematization of the motion-properties of bodies. By virtue of these concepts each body is regarded as a function of all other bodies; and these concepts may thus be said to possess a 1 For a more thorough examination of this error, see below, Ch. VIII, passim. |