of the sexual appetite,
civilization has transformed it into artificial enjoyment, and has
invented all possible means to increase and diversify it.

As far back as the history of civilization goes we see this state of
affairs, and in this sense we are neither better nor worse than our
ancestors. But we possess more diverse and more refined measures than
barbarian peoples, and than our direct ancestors, to satisfy our
unwholesome desires. Modern art in particular often serves to excite
eroticism, and we must frankly admit that it often descends to the
level of pornography. Hypocritical indignation against those who dare
to say this often serves only to cover in the name of art the most
indecent excitants of eroticism.

Photography and all the perfected methods of reproduction of pictures,
the increasing means of travel which facilitate clandestine sexual
relations, the industrial art which ornaments our apartments, the
increasing luxury and comfort of dwellings, beds, etc., are, at the
present day, so many factors in the science of erotic voluptuousness.
Prostitution itself has become adapted to all the pathological
excrescences of vice. In a word, the artificial culture of the human
sexual appetite has given rise to a veritable high school of
debauchery. The artistic and realistic representations of erotic
sexual scenes, so widespread at the present day, are much more capable
of exciting the sexual appetite than the crude and unnatural pictures
of former days, when, however, erotic objects of art generally
belonged to a few rich persons or to museums.

=Influence of Repeated Sexual Excitations.=--The artificial and varied
repetition of sexual excitation, by means of objects which provoke it,
increases the sexual appetite. This cannot be doubted, for the law of
exercise is a general truth in the physiology of the nervous system.
This law, which is also called the law of training, shows that every
kind of nervous activity is increased by exercise. A man becomes a
glutton by accustoming himself to eat too much, a good walker by
exercising his legs. The habit of wearing fine clothes or of washing
in cold water causes these things to become a necessity. By
continually occupying ourselves with a certain thing, we take a liking
for it and often become virtuosos. By always thinking of a disease we
are led to imagine that we suffer from it. A melody too often repeated
often becomes automatic and we whistle or hum it unconsc