M AN, as we all know from our common experience, is a subtle beast. We read that he is the only one which lies, whose cheeks redden with shame, and the only one whose nobility and degradation remain ambiguous. His nature is hidden, and even when he most wishes to express that nature, he succeeds in expressing only what he is not. As Kierkegaard notices, can combine silence with speech; for when he chatters he says nothing, and when he talks seriously, it is what he doesn't say that matters. This duplicity, this inverted, reflexive, paradoxical, and secret character of has never really escaped anyone who has seriously tried to know another. It has, I believe, escaped those who wish to turn the knowledge of by men into a science. Man can conceal his nature not only from others, but alas, finally from himself, at least in his scientific moods. It is a commonplace that investigator, method, and subject-matter must be correlatively appropriate to one another. A blind cannot investigate the phenomenon of color; and if he had the proper organs, he could not investigate it by sheer logic. Neither can we investigate what is unique in the individual by statistical methods, nor what is common to the group by an intuition of the individual. These general considerations, I suppose, would be disputed by none, although we might quarrel with any particular example. And the controlling factor in this total correlation is the subject-matter. It is the peculiarities of the subject-matter which dictate both the appropriate to the investigation of that subject-matter, and the faculties and characteristics of the investigator which should be appropriate to the employment of the method and the collection of facts. Since wants to learn what its subjectmatter is, both the of the and the scientist himself must be appropriate to it. It is to the subject-matter that we must make our adequate, not vice versa. Truth is an adequation of the intellect and its opinions to what is. Now it is also a platitude that the of are the youngest of the sciences. Psychology, sociology, anthropology, critical history, and the rest of the Geisteswissenshaften were late-comers among the sciences, although it is very far from being the case that the knowledge of is later in origin than the of the physical world. Men have always known something about themselves and their fellows, and while this knowledge was not organized into a body of propositions with accompanying methods of verification, it was still knowledge, and perhaps the soundest knowledge can ever acquire. The effort, however, to turn the knowledge of what men are into a rigorous is late in origin, and, it shall be my contention here, a mistaken venture. There cannot be anything like a science of man which pretends to adequacy. The most adequate knowledge will never be anything but what it always was: the unprovable, unverified knowledge that poets, wise men, and lovers have, a knowledge which is true but which is not and which in principle cannot be formalized or turned into science. To deny that can be an object of is only meaningful if we clarify what we mean by science, as well as man. Alas, for the social sciences there already exists a good example of an example that has never ceased to intrigue them as