I have no direct concern with Mr. Russell's solution of his problem. But if the prior analysis is correct, one may anticipate in advance that it will consist simply in making explicit the assumptions which have tacitly been made in stating the problem—subject to the conditions involved in failure to recognize that they have been made. And I think an analytic reading of the solution will bear out the following statement. His various "peculiar," "private" points of view and their perspectives are nothing but names for the positions and projectional perspectives of the ordinary space of the public worlds. Their correlation by likeness is nothing but the explicit recognition that they are all defined and located, from the start, in one common spatial continuum. One quotation must suffice. "If two men are sitting in a room, two somewhat similar worlds are perceived by them; if a third man enters and sits between them, a third world, intermediate between the two others, begins to be perceived" (pp. 87-88). Pray what is this room and what defines the position (standpoint and perspective) of the two men and the standpoint "intermediate" between them? If the room and all the positions and perspectives which they determine are only within, say, Mr. Russell's private world, that private world is interestingly complex, but it gives only the original problem over again, not a "solution" of it. It is a long way from likenesses within a private world to likenesses between private worlds. And if the worlds are all private, pray who judges their likeness or unlikeness? This sort of thing makes one conclude that Mr. Russell's actual procedure is the reverse of his professed one. He really starts with one room as a spatial continuum within which different positions and projections are determined, and which are readily correlated with one another just because they are projections from positions within one and the same space-room. Having employed this, he, then, can assign different positions to different percipients and institute a comparison between what each perceives and pass upon the extent of the likeness which exists between them.
What is the bearing of this account upon the "empirical datum"? Just this: The correlation of correlative series of changes which defines the object of sense perception is in no sense an original historic or psychologic datum. It signifies the result of an analysis of the usual crude empirical data, and an analysis which is made possible only by a very complex knowledge of the world. It marks not a primitive psychologic datum but an outcome, a limit, of analysis of a vast amount of empirical objects. The definition of an object as a correlation of various subcorrelations of changes represents a great advance—so it seems to me—over the definition of an object as a number of adjectives stuck into a substantive; but it represents an improved definition made possible by the advance of scientific knowledge about the common-sense world. It is a definition not only wholly independent of the context in which Mr. Russell arrives at it, but is one which (once more and finally) assumes extensive and accurate knowledge of just the world professedly called into question.
II
I have come to the point of transition to the other part of my paper. A formal analysis is necessarily dialectical in character. As an empiricist I share in the dissatisfaction which even the most correct dialectical discussion is likely to arouse when brought to bear on matters of fact. I do not doubt that readers will feel that some fact of an important character in Mr. Russell's statement has been left untouched by the previous analysis—even upon the supposition that the criticisms are just. Particularly will it be felt, I think, that psychology affords to his statement of the problem a support of fact not affected by any logical treatment. For this reason I append a summary statement as to the facts which are misconstrued by any statement which makes the existence of the world problematic.
I do not believe a psychologist would go as far as to admit that a definite correlation of elements as specific and ordered as that of Mr. Russell's statement is a primitive psychological datum. Many would doubtless hold that patches of colored extensity, sounds, kinaesthetic qualities, etc., are psychologically much more primitive than, say, a table, to say nothing of a group of objects in space or a series of events in time; they would say, accordingly, that there is a real problem as to how we infer or construct the latter on the basis of the former. At the same time I do not believe that they would deny that their own knowledge of the existence and nature of the ultimate and irreducible qualities of sense is the product of a long, careful, and elaborate analysis to which the sciences of physiology, anatomy, and controlled processes of experimental observation have contributed. The ordinary method of reconciling these two seemingly inconsistent positions is to assume that the original sensible data of experience, as they occurred in infancy, have been overlaid by all kinds of associations and inferential constructions so that it is now a work of intellectual art to recover them in their innocent purity.
Now I might urge that as matter of fact the reconstruction of the experience of infancy is itself an inference from present experience of an objective world, and hence cannot be employed to make a problem out of the knowledge of the existence of that world. But such a retort involves just the dialectic excursus which I am here anxious to avoid. I am on matter-of-fact ground when I point out that the assumption that even infancy begins with such highly discriminated particulars as those enumerated is not only highly dubious but has been challenged by eminent psychologists. According to Mr. James, for example, the original datum is large but confused, and specific sensible qualities represent the result of discriminations. In this case, the elementary data, instead of being primitive empirical data, are the last terms, the limits, of the discriminations we have been able to make. That knowledge grows from a confusedly experienced external world to a world experienced as ordered and specified would then be the teaching of psychological science, but at no point would the mind be confronted with the problem of inferring a world. Into the arguments in behalf of such a psychology of original experience I shall not go, beyond pointing out the extreme improbability (in view of what is known about instincts and about the nervous system) that the starting-point is a quality corresponding to the functioning of a single sense organ, much less of a single neuronic unit of a sense organ. If one adds, as a hypothesis, that even the most rudimentary conscious experience contains within itself the element of suggestion or expectation, it will be granted that the object of conscious experience even with an infant is homogeneous with the world of the adult. One may be unwilling to concede the hypothesis. But no one can deny that inference from one thing to another is itself an empirical event, and that just as soon as such inference occurs, even in the simplest form of anticipation and prevision, a world exists like in kind to that of the adult.
I cannot think that it is a trivial coincidence that psychological analysis of sense perception came into existence along with that method of experimentally controlled observation which marks the beginning of modern science. Modern science did not begin with discovery of any new kind of inference. It began with the recognition of the need of different data if inference is to proceed safely. It was contended that starting with the ordinary—or customary—objects of perception hopelessly compromised in advance the work of inference and classification. Hence the demand for an experimental resolution of the common-sense objects in order to get data less ambiguous, more minute, and more extensive. Increasing knowledge of the structure of the nervous system fell in with increased knowledge of other objects to make possible a discrimination of specific qualities in all their diversity; it brought to light that habits, individual and social (through influence on the formation of individual habits), were large factors in determining the accepted or current system of objects. It was brought to light, in other words, that factors of chance, habit, and other non-rational factors were greater influences than intellectual inquiry in determining what men currently believed about the world. What psychological analysis contributed was, then, not primitive historic data out of which a world had somehow to be extracted, but an analysis of the world which had been previously thought of and believed in, into data making possible better inferences and beliefs about the world. Analysis of the influences customarily determining belief and inference was a powerful force in the movement to improve knowledge of the world.
This statement of matters of fact bears out, it will be observed, the conclusions of the dialectical analysis. That brought out the fact that the ultimate and elementary data of sense perception are identified and described as limiting elements in a complex world. What is now added is that such an identification of elements marks a significant addition to the resources of the technique of inquiry devoted to improving knowledge of the world. When these data are isolated from their logical status and office, they are inevitably treated as self-sufficient, and they leave upon our hands the insoluble, because self-contradictory, problem of deriving from them the world of common-sense and science. Taken for what they really are, they are elements detected in the world and serving to guide and check our inferences about it. They are never self-inclosed particulars; they are always—even as crudely given—connected with other things in experience. But analysis gets them in the form where they are keys to much more significant relations. In short, the particulars of perception, taken as complete and independent, make nonsense. Taken as objects discriminated for the purposes of improving, reorganizing, and testing knowledge of the world they are invaluable assets. The material fallacy lying behind the formal fallacy which the first part of this paper noted is the failure to recognize that what is doubtful is not the existence of the world but the validity of certain customary yet inferential beliefs about things in it. It is not the common-sense world which is doubtful, or which is inferential, but common-sense as a complex of beliefs about specific things and relations in the world. Hence never in any actual procedure of inquiry do we throw the existence of the world into doubt, nor can we do so without self-contradiction. We doubt some received piece of "knowledge" about some specific thing of that world, and then set to work, as best we can, to rectify it. The contribution of psychological science to determining unambiguous data and eliminating the irrelevant influences of passion and habit which control the inferences of common-sense is an important aid in the technique of such rectifications.