Nothing is more clear than that the enjoyment of art and letters is forbidden, in any rich or subtle degree, to the apprehension of the moralist. It is also forbidden, for quite other reasons, to the apprehension of the extravagantly vicious. The moralist is debarred from any free and passionate love of literature by the simple fact that all literature is created out of the vices of men of letters. The extravagantly vicious man is debarred from such a love by the still simpler fact that his own dominant obsession narrows down his interest to the particular writers who share his own vice. When I encounter a catholic and impassioned lover of books--of many books and many authors--I know two things about him--I know that he is the opposite of a moralist, and I know that he is free from any maniacal vice. I might go further and say that I know he has a rooted hatred of moralists and a tolerant curiosity about every other form of human aberration. When I say that literature is created out of the vices of men of letters, I use the word in a large and liberal sense. A vice is a pleasant sensation condemned by Puritans. It is an over-emphasis laid upon some normal reaction; or it is a perverse and morbid deviation from the normal path. It would not require any fantastic stretch of psychological interpretation to show how all the great men of letters are driven forward along their various paths by some demoniac urge, some dynamic impulse, that has its sensual as well as its intellectual origin. The "psychology of genius" is still in its infancy. It seems a pity that so much of the critical interpretation of the great writers of the world should be in the hands of persons who--by the reason of their academic profession--are naturally more interested in the effect of such work upon youthful minds than in its intrinsic quality. The barbaric vulgarity of our commercial age is largely responsible for the invidious slur cast upon any genuine critical psychology; upon any psychology which frankly recognises the enormous influence in literature exercised by normal or abnormal sexual impulses. Criticism of literature which has nothing to say about the particular sexual impulse--natural or vicious, as it may happen--which drives a writer forward, becomes as dull and unenlightening as theology without the Real Presence. Among the influences that obstruct such free criticism among us at present may be noted Puritan fanaticism, academic professionalism (with its cult of the "young person"), popular vulgarity, and that curious Anglo-Saxon uneasiness and reticence in these things which while in no sense a sign of purity of mind invokes an invincible prejudice against any sort of straightforward discussion.