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 sexual act the role of the woman differs from that of the man not only by being passive, but also by the absence of seminal ejaculations. In spite of this the analogies are considerable. The erection of the clitoris and its voluptuous sensations, the secretion from the glands of _Bartholin_ which resembles ejaculation in the male, the venereal orgasm itself which often exceeds in intensity that of man, are phenomena which establish harmony in sexual connection.