These phenomena are of fundamental importance in the question of the sexual appetite. Here, the well-known axiom of moderation which says, "Abuse does not exclude use" finds its application. An English commentator on _Cicero_ erroneously attributes to him the following: "True moderation consists in the absolute domination of the passions and appetites, as well as all wrong desires, by reason. It exacts total abstinence from all things which are not good and which are not of an absolutely innocent character." This definition is excellent, although it is not _Cicero's_. It excludes, for example, the use of a toxic substance such as alcohol, which is not a natural food, but not the moderate satisfaction of the sexual appetite which is normally intended for the preservation of the species, for this satisfaction may be good or bad, normal or vicious, innocent or criminal, according to circumstances. In this connection, the application of the right measure, and choice of the appropriate object raise delicate and complicated questions. So-called moral sermons lead to nothing in this domain. After numerous personal observations made on very diverse individuals who have consulted me with regard to sexual questions, I think I can affirm that when a man wishes to be loyal to himself he is generally able to distinguish between natural desire and artificial excitation of the sexual appetite. To be pursued and tormented by sexual images and desires, even when striving against them, and when the legitimate and normal occasion to satisfy them is absent, is not the same thing as to pass the time in inventing means of artificial excitement to pleasure and orgy while leading an idle and egoistic life. I speak here of the normal man and not of certain pathological states in which the sexual appetite takes the character of a perpetual obsession, even against the will of the patient. By serious and persevering work and by avoiding all means of excitation, the sexual appetite can usually be kept within the bounds of moderation. We have mentioned above pornographic art as one of the means which artificially excite the sexual appetite. Along with the interested exploitation of the habit of taking alcoholic drinks, exploitation of the sexual appetite constitutes one of the largest fields of what may be called _social brigandage_. Besides pornographic pictures, the principal means employed to artificially excite the sexual weaknesses of man are the following: _Pornographic novels_ in which sexual desire is excited by all the artifice of the novelist, and in which the illustrations often rival those we have just spoken of to seduce the purchaser. _Alcohol_ which, by paralyzing the judgment and will as well as moral inhibitory sentiments, excites the sexual appetite and renders it grossly impulsive. Its first fumes make man enterprising, and he falls an easy prey to proxenetism and prostitution, although it soon weakens the sexual power.