Let us begin, then, with the madhouse; from this evil and fantastic inn let us set forth on our intellectual journey. Now, if we are to glance at the philosophy of sanity, the first thing to do in the matter is to blot out one big and common mistake. There is a notion adrift everywhere that imagination, especially mystical imagination, is dangerous to man’s mental balance. Poets are commonly spoken of as psychologically unreliable; and generally there is a vague association between wreathing laurels in your hair and sticking straws in it. Facts and history utterly contradict this view. Most of the very great poets have been not only sane, but extremely businesslike; and if Shakespeare ever really held horses, it was because he was much the safest man to hold them. Imagination does not breed insanity. Exactly what does breed insanity is reason. Poets do not go mad; but chess-players do. Mathematicians go mad, and cashiers; but creative artists very seldom. I am not, as will be seen, in any sense attacking logic: I only say that this danger does lie in logic, not in imagination. Artistic paternity is as wholesome as physical paternity. Moreover, it is worthy of remark that when a poet really was morbid it was commonly because he had some weak spot of rationality on his brain.