Elements of metaphysics

by A. E. Taylor

A word may be said as to the nature of the practical need upon which the postulate of Uniformity is based. As we have previously seen, the allied postulate of Causality arose from the practical need of devising means for the control of natural processes. But the causal postulate alone is not enough to satisfy this need. For even if we can assume that every event is determined, sufficiently for practical purposes, by its antecedents, and thus that the knowledge of those antecedents, when obtained, is a knowledge of the means to its production, our practical command over the production of the event is not yet assured. For we can have no general confidence in our power to produce the event by employing the ascertained means, so long as it is possible that the result may on each occasion be affected by variations too minute for our detection, or for other reasons not accessible to our perception. We need to be assured that what seems the same to us is, for practical purposes, the same, and so that the employment of the same means may be trusted to lead to the same result. This is the condition which is expressed in an abstract form by the principle of Uniformity, which states that the course of natural processes conforms to general laws; in their actual application to the concrete processes of actual nature these laws are properly practical rules for the production of effects, and their inviolability means no more than that we may successfully treat as the same, in their bearing on the results in which we are interested, things which appear the same in relation to certain standards of comparison. As we have seen, the validity of this assumption could never have been known a priori; it can only be said to be actually valid where actual use has justified it. At the same time, it is clearly a principle of method to assume the universal applicability of our practical postulates wherever it is to our interest that they should be applicable, as explained in the last paragraph. This is why we rightly assume the applicability of the postulates in spheres where the successful establishment of general uniformities has not hitherto been effected, so long as no positive reason can be shown why they should not apply. We shall find this last reflection suggestive when we come to deal with the ethical difficulties which have been felt about the application of the postulates of Uniformity and Causality to voluntary action.

It is of course clear that our reduction of Uniformity to a mere practical postulate does not introduce any element of pure “chance” into the actual order of existing things. “Chance” is a term with more than one meaning, and its ambiguity may easily lead to misapprehensions. Chance may mean (a) any sequence for which our actual knowledge cannot assign the ground. In this sense chance, as another name for our own mere ignorance, must of course be recognised by any theory which does not lose sight of the fact of human ignorance and fallibility.

Or again, chance may mean (b) a sequence of which the ground is partially understood. We may know enough of the ground of the sequence to be able to limit the possibilities to a definite number of alternatives, without knowing enough to say which alternative completely satisfies the conditions in a special case. It is in this sense that we speak of the “chances” of any one of the alternative events as capable of computation, and make the rules for their computation the object of special mathematical elaboration in the so-called “Theory of Probability.”

(c) Finally, chance may mean “pure” chance, the existence of something for which there is no “ground” whatever, as it stands in no organic interconnection with a wider system of real existence. Chance in this last sense is, of course, absolutely excluded by our conception of the systematic unity of the real as expressed in the principle of Ground and Consequence, as an ultimate axiom of all consistent thought. Our denial of the absolute validity of the principles of Causality and Uniformity would only amount to the admission of “pure” chance into things if we accepted those principles as necessary consequences of the axiom of Ground and Consequence. If they are mere practical postulates, which present the axiom of Ground under artificial restrictions for which there is no logical justification in the axiom itself, the admission that they are not ultimately true in no way conflicts with full recognition of the thorough systematic unity of existence; it merely means that the view of the nature of that unity assumed by our practical postulates, though eminently useful, is inadequate.

We may here conveniently recapitulate our results. On metaphysical grounds, we felt compelled to regard the physical order as the manifestation to our special sensibility of a system of interconnected beings with sentient and purposive experiences like ourselves. The apparent purposelessness and deadness of the greater part of that order we explained as intelligible on the supposition that the subjective purposes and interests of many of its members are too unlike our own for our recognition. We then saw that if nature consists of such sentient experiences, the apparent domination of it by absolute law and uniformity cannot be the final truth. Such uniformity as there is must be approximate, and must result from our having to deal in bulk with collections of facts which we cannot follow in their individual detail, and will thus be of the same type as the statistical uniformities established by the anthropological sciences in various departments of human conduct. Next, we saw that the uniformities we call the “laws” of nature are, in fact, of this type; that they represent average results computed from a comparison of large collections of instances with which we cannot, or cannot so long as we adhere to our scientific purpose, deal individually, are only absolute while they remain hypothetical, and never afford ground for absolute assertion as to the course of concrete events.

We further saw that the only uniformity science requires of the actual course of nature is uniformity sufficiently close to enable us, for our special purposes, to neglect the individual deviations, and that the principle of Uniformity itself is not a logical axiom but a practical postulate, expressing the condition necessary for the successful formulation of rules for practical intervention in the course of events. Finally, while we saw that we have no a priori logical warrant for the assumption that such rules can be formulated for all departments of the physical order, we are bound on methodological grounds to assume that they can, unless we have special positive reasons for believing the contrary. Thus the universality of a postulate of uniformity does not mean that it is universally true, but that it has universally to be made wherever we have an interest in attempting the formulation of general rules.

§ 5. (4) The Conception of the Physical Order as a Mechanism. The conception of nature as rigidly conformable to general laws, finds its completest expression in the view of the whole physical order as a complicated mechanism.

It is not easy to say just how much is always implied when we hear of a “purely mechanical” theory of the world or of physical processes. Sometimes all that is meant is that the theory in question treats the principle of rigid uniformity according to general laws as an ultimate axiom. Sometimes, again, a “mechanical view” of the world is taken to mean, in a narrower sense, one which regards all the chemical, electrical, and other processes of the physical order as merely complicated cases of change of configuration in a system of mass particles. In this narrower sense the “mechanical” theory of the physical world is another name for the somewhat crude form of realist Metaphysics according to which nothing exists but moving masses, everything in the form of secondary qualities being a subjective illusion. Both the wider and the narrower form of the mechanical view agree in treating the processes of physical nature as unintelligent and unconscious, and regarding them as completely determined by antecedent conditions, without reference to any end or purpose which they effect. The theory owes the epithet “mechanical” to the analogy which is then supposed to subsist between the physical order and the various machines of human construction, in which the various constituent parts similarly execute movements determined by relation to the remaining parts, and not by any consciousness of an end to be attained.[^[138]]

It is of course manifest that, so understood, the mechanical view of physical processes is forced upon us by our practical needs wherever it is requisite to formulate rules for successful intervention in the course of nature. If we are to intervene with success in the course of events, that course must, as we have already seen, be capable of being regarded as approximately uniform, otherwise we can have no security that our intervention according to rule and precedent will have a uniform and unambiguous result. Hence, if we are to formulate general rules for practical intervention, we must be able to treat the course of things as—to all intents and purposes—mechanical. And, on the contrary, if there are processes which cannot be even approximately regarded as mechanical, our power of framing general rules for the practical manipulation of events cannot extend to those processes. The limits of the mechanical view of events are likewise the limits of empirical science and of the general precepts of the practical arts.

We see this admirably exemplified in the study of human natures. The behaviour of large aggregates of human beings, as we have already learned, exhibits approximate uniformity, at least in many respects, and may thus be treated as to all intents and purposes mechanical in those respects. Hence it is possible to have a number of empirical sciences of human nature, such as Ethnology and Sociology, in which those uniformities are collected and codified, and to base on these sciences a number of general prudential maxims for the regulation of our behaviour towards our fellow-men considered in the abstract. But when we come to deal with the actual conduct of concrete human individuals, the mechanical view, as we have seen, fails us. What a concrete individual will do can only be inferred with certainty from the knowledge of his interests and purposes; there can thus be no general science of individual character, and consequently no general rules of prudence for behaviour towards an individual fellow-man. It is not to the so-called sciences of human nature, but to personal experience of the individual himself, we have to go for the knowledge how to regulate our conduct towards the actual individuals with whom life brings us into direct and intimate personal relation. Philosophical reflection upon the nature and limits of scientific knowledge fully confirms the verdict passed by the practical sense of mankind on the doctrinaire pedantry which seeks to deduce rules for dealing with actual individuals from anything but concrete understanding of individual character and purpose.