These arguments, however, do not apply to sensation. It is especially sensation, I think, which is considered by those realists who retain only the object.* Their views, which are chiefly held in America, are in large measure derived from William James, and before going further it will be well to consider the revolutionary doctrine which he advocated. I believe this doctrine contains important new truth, and what I shall have to say will be in a considerable measure inspired by it. * This is explicitly the case with Mach's "Analysis of Sensations," a book of fundamental importance in the present connection. (Translation of fifth German edition, Open Court Co., 1914. First German edition, 1886.) William James's view was first set forth in an essay called "Does 'consciousness' exist?"* In this essay he explains how what used to be the soul has gradually been refined down to the "transcendental ego," which, he says, "attenuates itself to a thoroughly ghostly condition, being only a name for the fact that the 'content' of experience IS KNOWN. It loses personal form and activity--these passing over to the content--and becomes a bare Bewusstheit or Bewusstsein uberhaupt, of which in its own right absolutely nothing can be said. I believe (he continues) that 'consciousness,' when once it has evaporated to this estate of pure diaphaneity, is on the point of disappearing altogether. It is the name of a nonentity, and has no right to a place among first principles. Those who still 6 cling to it are clinging to a mere echo, the faint rumour left behind by the disappearing 'soul' upon the air of philosophy"(p. 2). * "Journal of Philosophy, Psychology and Scientific Methods," vol. i, 1904. Reprinted in "Essays in Radical Empiricism" (Longmans, Green & Co., 1912), pp. 1-38, to which references in what follows refer. He explains that this is no sudden change in his opinions. "For twenty years past," he says, "I have mistrusted 'consciousness' as an entity; for seven or eight years past I have suggested its non-existence to my students, and tried to give them its pragmatic equivalent in realities of experience. It seems to me that the hour is ripe for it to be openly and universally discarded"(p. 3). His next concern is to explain away the air of paradox, for James was never wilfully paradoxical. "Undeniably," he says, "'thoughts' do exist." "I mean only to deny that the word stands for an entity, but to insist most emphatically that it does stand for a function. There is, I mean, no aboriginal stuff or quality of being, contrasted with that of which material objects are made, out of which our thoughts of them are made; but there is a function in experience which thoughts perform, and for the performance of which this quality of being is invoked. That function is KNOWING"(pp. 3-4). James's view is that the raw material out of which the world is built up is not of two sorts, one matter and the other mind, but that it is arranged in different patterns by its interrelations, and that some arrangements may be called mental, while others may be called physical. "My thesis is," he says, "that if we start with the supposition that there is only one primal stuff or material in the world, a stuff of which everything is composed, and if we call that stuff 'pure experience,' then knowing can easily be explained as a particular sort of relation towards one another into which portions of pure experience may enter. The relation itself is a part of pure experience; one of its 'terms' becomes the subject or bearer of the knowledge, the knower, the other becomes the object known"(p. 4). After mentioning the duality of subject and object, which is supposed to constitute consciousness, he proceeds in italics: "EXPERIENCE, I BELIEVE, HAS NO SUCH INNER DUPLICITY; AND THE SEPARATION OF IT INTO CONSCIOUSNESS AND CONTENT COMES, NOT BY WAY OF SUBTRACTION, BUT BY WAY OF ADDITION"(p. 9). He illustrates his meaning by the analogy of paint as it appears in a paint-shop and as it appears in a picture: in the one case it is just "saleable matter," while in the other it "performs a spiritual function. Just so, I maintain (he continues), does a given undivided portion of experience, taken in one context of associates, play the part of a knower, of a state of mind, of 'consciousness'; while in a different context the same undivided bit of experience plays the part of a thing known, of an objective 'content.' In a word, in one group it figures as a thought, in another group as a thing"(pp. 9-10). He does not believe in the supposed immediate certainty of thought. "Let the case be what it may in others," he says, "I am as confident as I am of anything that, in myself, the stream of thinking (which I recognize emphatically as a phenomenon) is only a careless name for what, when scrutinized, reveals itself to consist chiefly of the stream of my breathing. The 'I think' which Kant said must be able to accompany all my objects, is the 'I breathe' which actually does accompany them"(pp. 36-37). The same view of "consciousness" is set forth in the succeeding essay, "A World of Pure Experience" (ib., pp. 39-91). The use of the phrase "pure experience" in both essays points to a lingering influence of idealism. "Experience," like "consciousness," must be a product, not part of the primary stuff of the world. It must be possible, if James is right in his main contentions, that roughly the same stuff, differently arranged, would not give rise to anything that could be called "experience." This word has been dropped by the American realists, among whom we may mention specially Professor R. B. Perry of Harvard and Mr. Edwin B. Holt. The interests of this school are in general philosophy and the philosophy of the sciences, rather than in psychology; they have derived a strong impulsion from James, but have more interest than he had in logic and mathematics and the abstract part of philosophy. They speak of "neutral" entities as the stuff out of which both mind and matter are constructed. Thus Holt says: "If the terms and propositions of logic must be substantialized, they are all strictly of one substance, for which perhaps the least dangerous name is neutral-stuff. The relation of neutral-stuff to matter and mind we shall have presently to consider at considerable length." * * "The Concept of Consciousness" (Geo. Allen & Co., 1914), p. 52. My own belief--for which the reasons will appear in subsequent lectures--is that James is right in rejecting consciousness as an entity, and that the American realists are partly right, though not wholly, in considering that both mind and matter are composed of a neutral-stuff which, in isolation, is neither mental nor material. I should admit this view as regards sensations: what is heard or seen belongs equally to psychology and to physics. But I should say that images belong only to the mental world, while those occurrences (if any) which do not form part of any "experience" belong only to the physical world. There are, it seems to me, prima facie differ- 7 ent kinds of causal laws, one belonging to physics and the other to psychology. The law of gravitation, for example, is a physical law, while the law of association is a psychological law. Sensations are subject to both kinds of laws, and are therefore truly "neutral" in Holt's sense. But entities subject only to physical laws, or only to psychological laws, are not neutral, and may be called respectively purely material and purely mental. Even those, however, which are purely mental will not have that intrinsic reference to objects which Brentano assigns to them and which constitutes the essence of "consciousness" as ordinarily understood. But it is now time to pass on to other modern tendencies, also hostile to "consciousness." There is a psychological school called "Behaviourists," of whom the protagonist is Professor John B. Watson,* formerly of the Johns Hopkins University. To them also, on the whole, belongs Professor John Dewey, who, with James and Dr. Schiller, was one of the three founders of pragmatism. The view of the "behaviourists" is that nothing can be known except by external observation. They deny altogether that there is a separate source of knowledge called "introspection," by which we can know things about ourselves which we could never observe in others. They do not by any means deny that all sorts of things MAY go on in our minds: they only say that such things, if they occur, are not susceptible of scientific observation, and do not therefore concern psychology as a science. Psychology as a science, they say, is only concerned with BEHAVIOUR,
i.e. with what we DO; this alone, they contend, can be accurately observed. Whether we think meanwhile, they tell us, cannot be known; in their observation of the behaviour of human beings, they have not so far found any evidence of thought. True, we talk a great deal, and imagine that in so doing we are showing that we can think; but behaviourists say that the talk they have to listen to can be explained without supposing that people think. Where you might expect a chapter on "thought processes" you come instead upon a chapter on "The Language Habit." It is humiliating to find how terribly adequate this hypothesis turns out to be. * See especially his "Behavior: an Introduction to Comparative Psychology," New York, 1914. Behaviourism has not, however, sprung from observing the folly of men. It is the wisdom of animals that has suggested the view. It has always been a common topic of popular discussion whether animals "think." On this topic people are prepared to take sides without having the vaguest idea what they mean by "thinking." Those who desired to investigate such questions were led to observe the behaviour of animals, in the hope that their behaviour would throw some light on their mental faculties. At first sight, it might seem that this is so. People say that
