Nor are we more fortunate when we turn to psychology for an account of how the original Chinese inventor came to conceive his epoch-making idea. This fact, of course, falls under the heading of ‘imagination’, and about imagination psychologists have much to tell us. But what, after all, does their interpretation amount to? We learn that imagination, as distinguished from the power of abstract thought, is the power of forming new concrete ideas. Since even the concrete individual idea is complex, being a product of association, its elements may be linked differently so as to produce new combinations. “The inventor of a new mechanism,” says Höffding, “combines given elements, the laws of whose activity he knows, into a totality and a connection which has no complete parallel in experience.” The scientist tries all possible combinations among his elements of experiences, forming a succession of individual ideas, which are rejected until the one appears that adequately represents reality. We need hardly go farther to realize the impotence of psychological science for illuminating the _psychology_ as well as the history of the paper-making art. The formulation of psychological science is admirable, but it is too general. It explains the invention of the steam-engine and the phonograph, the sewing-machine and the harvester no less than the origin of paper-making. We, however, do not want to know merely what ultimate psychological processes the invention of paper-making shares with all other inventions whatsoever, but also the _differential_ conditions that produced this one and unique result under the given circumstances. It is as though we asked about a man’s character and were told that he was a vertebrate. The type of psychological explanation we want is by no means unknown; however, we shall find its illustrations not in text-books of psychology, but in histories of literature, science, and art. When Taine raises the question how such a bore as Dr. Samuel Johnson could conceivably have attained his position in English literature and answers that it is because of the English predilection for sermons, he is giving the type of solution--whether right or wrong--that we want to secure for our cultural problem; it explains why the average Englishman, as a member of English society, acquires the habit of regarding Johnson in a certain way. When we inquire why Newton closes his treatise on optics with a statement as to the vanity of human things, our curiosity is satisfied when this expression appears as only one instance of the blending of theological and scientific thought current in his day. It is nonsense to say that these explanations are purely historical; they are psychological, for they take fully into account the subjective attitudes involved in the phenomena studied; and it is hopeless to expect this sort of explanation from psychological science, which deals with a quite distinct and far more generalized form of mental activity.