It is needless to say that the mental qualities react powerfully on the sexual appetite. A quarrelsome temper, coldness and repulsion on the part of a woman cool the desires of the man, while an ardent sexual desire on the part of the woman, her love and tenderness, tend to increase and maintain them. We are dealing here with purely animal sexual instinct, and we may state that the sexual appetite of woman generally excites strongly that of man, and considerably increases his pleasure during coitus. There are, however, exceptions in the inverse sense, in which coldness and disgust on the part of the woman excite the passion of certain men, who have, however, no taste for libidinous women. All degrees are found in this domain. Active in the sexual act the man desires corresponding sentiments in the woman. But, on the other hand, all want of natural reserve, and delicate sentiment, and all cynical sexual provocation on the part of a woman, produce in the normal man a repulsive effect. The normal woman possesses an admirable instinct in these matters and knows how to betray her feelings in a sufficiently fine and delicate manner, so as not to hurt those of the man. A phenomenon, which we shall meet with in Chapter VIII, under the name of _psychic impotence_, shows the powerful and disturbing interference of thoughts on the automatic action of instinctive sexual activity. A momentary psychic impotence is not necessarily pathological. While voluptuous sensations alternate during coitus with desire and corresponding erotic representations, a sudden idea of the ridiculousness of the situation, signs of pain or of bad temper in the woman, the idea of impotence or of the real object of coitus; finally, anything which acts as a contrast to the sensations and impulses of coitus, may interrupt it, so that the voluptuous sensations and sexual appetite disappear and erection subsides. Voluntary efforts are often incapable of putting things right again. The charm is broken, and only new images and new sentiments associated instinctively with the sexual appetite can be reëstablished, by making the subconscious state preponderate over the reasoning consciousness.