(2) It will also follow that, at present and for long enough to come, Psychology is bound, pace Professor Münsterberg, to use both mechanical and teleological hypotheses and categories. Such a mixture of two different logical standpoints would no doubt be intolerable in a science which owed its existence to the need of satisfying a single interest of our nature. For the kind of interest which is met by mechanical hypotheses is baffled by the introduction of teleological modes of thought, and vice versâ. But, according to our view, the interest to which Psychology owes its creation is not single but double. We have an interest in the mechanical forecasting of human action, and an interest in its ethical and historical interpretation, and Psychology, as at present constituted, has to satisfy both these conflicting interests at once. Hence the impossibility of confining it either to purely mechanical or to purely teleological categories. If, indeed, our Physiology had reached the point of ideal completeness, so that every routine uniformity at present expressed in psychological terminology as the establishment of an “association” or “habit” could be translated into its physiological correlate, we should be able to dispense altogether with psychological hypotheses as aids to the calculation of the course of events, and to restore logical unity to Psychology by confining it entirely to the task of providing Ethics and History with the teleological categories they require for the description of their subject-matter. But such a reform of method would be most premature in the present condition of our physiological knowledge.[[172]]
§ 6. There are two points of difficulty which our discussion has so far failed to deal with, but must not leave entirely unnoticed. We have allowed ourselves to assume (a) that description in psychological terms, and (b) that description in teleological terms, are possible. Both these assumptions have been questioned, and it is clear that if the first is unsound there can be no science of Psychology at all, while, if the second is unsound, Psychology cannot use teleological conceptions. Hence it is absolutely necessary to attempt some justification of our position on both questions.
As to (a), it has been argued that since only that which is accessible on equal terms to the perception of a plurality of subjects can be described by one subject to another, and since all objects so accessible to the perception of a plurality of subjects were included in our construction of the physical order, description can only be of physical objects. A “mental state” must be in principle incapable of description, because it can only be experienced by one subject.
Now, if Psychology claimed to be the direct description of immediate experience, as it is experienced, this contention would certainly be fatal to its very existence. But, as we have seen, Psychology makes no such claim. Its data are not the actualities of immediate experience themselves, but symbols derived from those actualities by a certain process of transformation. And though what Psychology calls its “facts” cannot, of course, like physical facts, be directly exhibited to the sense-perception of a plurality of subjects, we have in the physical conditions and concomitants of a “mental state” assignable marks by which we may recognise when it occurs in our own life, the actual experience of which the psychologist’s “mental state” is the symbol. Thus, though I cannot directly produce for inspection a sample of what in Psychology I call “the sensation of red,” I can indirectly, by assigning the upper and lower limits of the wave-length corresponding to the sensation, make every one understand what actual experience I am thinking of when I use the term.
(b) The second difficulty need not detain us long. The view that all description must be exclusively mechanical, rests upon the assumption that no other kind of description will answer the purpose for the sake of which we set out to describe things. Now, so far as description is undertaken for the purpose of establishing practical rules for intervention in the course of occurrences, this assumption is perfectly justified. If we are to lay down general rules for meddling in the course of events, we must of course assume that, apart from our meddling, it goes on with routine regularity. And we have already seen that for this very reason the mechanical interpretation of Nature is a fundamental postulate of physical science, so long as it confines itself strictly to the work of formulating “laws of Nature,” and does not attempt the task of historical appreciation. But, as we have also seen, the historical appreciation of a series of events as marked by the progressive execution of an underlying plan or purpose, is only possible when the events themselves have been described in essentially teleological terms as processes relative to ends.[[173]] Hence we have no right to contend that all scientific descriptions shall be of the mechanical type, unless we are also prepared to maintain that the only purpose they subserve is that of the formulation of general rules for practice.
If the historical appreciation of events is a legitimate human interest, the description of events in terms of end and purpose must also be a legitimate form of description. Now, in point of fact, even the “physical sciences” themselves, when they come to deal with the facts of organic life, largely desert the primary scientific ideal of the formation of general laws for the historical ideal of the detection of lines of individual development, and if our previous conclusions are correct, it is much more for the latter than for the former purpose that we are interested in the construction of a science of Psychology. What a human being wants Psychology for, in the main, is not so much to help him to forecast the behaviour of other men, as to assist him to understand how the successive stages of his own individual development and that of his “social environment” are knit into a unity by the presence of all-pervading permanent interests and ends. The contention that psychological description must, on grounds of logical method, be of the mechanical type, seems therefore to repose on misconception as to the uses of Psychology.
The preceding discussion may perhaps appear somewhat arid and wearisome, but it was indispensable that our subsequent examination of the metaphysical problems suggested by the recognition of the psychical realm of existence should be based upon a definite view as to the connection between psychological conceptions and the actualities of experience, and such a view, in its turn, presupposes a positive theory of the interests to which psychological construction ministers and the logical procedure by which it is affected. The general result of our investigation has gone to show negatively that Psychology is not a direct transcript of real experience, but an intellectual reconstruction involving systematic abstraction from and transformation of experience, and positively that the reconstruction depends for its legitimacy upon its serviceableness for the special purposes, partly of the practical anticipation of events, but principally of their historical and ethical appreciation. The significance of those conclusions will be more apparent in the course of the two following chapters.
Consult further:—R. Avenarius, Der Menschliche Weltbegriff; F. H. Bradley, “A Defence of Phenomenalism in Psychology” (Mind, January 1900); H. Münsterberg, Grundzüge der Psychologie, vol. i. chap. 2 (The Epistemological Basis of Psychology), 11 (Connection through the Body); J. Ward, Art. “Psychology” in Encyclopædia Britannica, ad init. (“The Standpoint of Psychology”); Naturalism and Agnosticism, vol. ii. lect. 16.
[168]. See Avenarius, Der Menschliche Weltbegriff, p. 115 ad fin.