That induction, as giving the experience value of things on basis of previous experience, is fundamental to all emotions about the things, has been implied throughout our discussion. But the inductive act may itself be emotively considered and intellectual emotion may arise. How and why induction came to be a pleasurable act and carried on for its own sake is, perhaps, not explainable by biologic evolution. It is certain that the inductive act, like other functions, arises as painful effort and as a mere means of serving life. Identifying and recognising is accomplished only under pressure of the struggle for existence. Animals in general, and, indeed, most human beings exercise their intelligence, make inductions, only as compelled by the demands of life. The Australian savages who guided Lumholtz in his search for new marsupials knew about the animals solely in a practical way, and were totally unable to comprehend Lumholtz’s motive. So geologists examining stones are entirely misapprehended by savages and the semi-civilized, though these people are sufficiently acquainted with stones so far as they are a source of mineral wealth, are useful for building, etc. And from the point of view of natural selection pure science, the pursuit of knowledge solely for its own sake, without the least reference to its appreciation, is unexplainable. Nevertheless, it is a fact that at a certain point in psychism the intellectual life develops for its own sake; the inductive act is pleasurable, and the desire arises to continue it as such, that is, here is true intellectual emotion, an emotion arising about an intellectual act represented as such. This feeling about induction may rise to an absorbing passion, as with Charles Darwin. He liked nothing better than making inductions, until he finally came to like little else. If the reason is asked for induction becoming pleasurable, and an end in itself psychology at present has no answer.