the sexual
appetite is let loose like a hurricane in the brain and becomes the
despot of the whole mind. The sexual passion has often been compared
to drunkenness or to mental disease. Even in its mildest forms it
often renders the husband incapable of sexual connection with his
wife.

For example, a man may cherish, respect and even adore his wife, and
yet her presence and touch may not appeal to his senses, nor excite
his appetite or erection; while some low-minded woman will produce in
him an irresistible sensual attraction, even when he experiences
neither esteem nor love for her. In such cases sexual appetite is in
more or less radical opposition to love. Such extreme phenomena are
not rare, but hardly common. Although excited to coitus with the woman
in question, the husband would not in any case have her for wife, nor
even have children by her, for after the slightest reflection he
despises and fears her. Here, the sexual appetite represents the old
atavistic animal instinct, attracted by libidinous looks, exuberant
charms, in a word by the sensual aspect of woman.

On the contrary, in a higher domain of the human mind, the sentiments
of sympathy of true love, deeply associated with fidelity, and with
intellectual and moral intimacy, unite against the elementary power of
the animal instinct. Here we see dwelling in the same breast (or, to
speak more correctly, in the same central nervous system) two souls,
which struggle with each other.

We are not dealing here with cases in which a new passion arrives to
turn the man from his old affection. No doubt the extreme cases of
which we have spoken are not usual, but we see in most men more or
less considerable mixtures of analogous sentiments in all possible
degrees, especially when the woman loved loses her physical
attractions from age or other causes.

=The Procreative Instinct.=--The sexual appetite of man does not
consist exclusively in the desire for coitus. In many cases it is
combined, more or less strongly and more or less consciously, with the
desire to procreate children. Unfortunately, this desire is far from
being always associated with higher sentiments and with love of
children or the paternal instinct. In fact, conscious reasoning plays
a smaller part than the animal instinct of self-expansion. We shall
see later on that the procreative instinct often plays an important
role in our present civilization.

=The Sexual Appetite in Woman.=--In the