The sense of taste is sometimes in the service of sexuality. One of the author’s patients had sexual sensations of a pleasurable character when eating liver-sausages. The sight of a beautiful specimen of the other sex, or even its picture only, may frequently excite the sexual centre. Emotional persons are often sexually excited by certain music. An exaggerated fondness for music is always suspicious of being of a sexual nature. The tactile sense is the main sense in the service of sexuality. The touch of any part of the male body by a soft female hand will cause sensual excitement. The touch of the nipple in woman often causes intense libido, a fact which plays an important part in the nursing of the young throughout all the types of mammals. The sexual sphere may also be excited by a stimulation of the gluteal region. The practice of the Flagellants was suppressed by the church when it was discovered that sensual motives played an important part in their exercises. Rousseau in his confessions describes the pleasure he felt when spanked by his nurse. Spanking often incites children to masturbation. The main irritation of the genitals is induced by touch. Erection, orgasm and ejaculation may be induced by the tactile irritation of the penis in the man and of the clitoris in a virgin, and after defloration, by the excitation of the anterior wall of the vagina. Certain zones of the skin become secondarily related to sexuality, mostly at such points where the skin turns into mucous membrane. These are the erogenous zones. [AE] The word love is, as a rule, employed very loosely and made to do duty for almost any attraction, whether purely physical or wholly sentimental. Even great philosophers and distinguished writers do rarely differentiate between animal passion and human love or between pure sensuality or the somatic part of sex, and mental attraction or the psychic phenomenon. Plato says that love between a man and a woman is mere animal passion, far inferior in nobility and importance to love for boys, friendship or filial, parental or brotherly love. According to Plato, Socrates understood nothing by love except its science, Ta Erotica. Eros Uranios incites to love youths only, the more intelligent sex, and this only at a time when their good character and high culture are beyond doubt. Plutarch says: The passion for women causes at the best the gain of sensual pleasure and the enjoyment of bodily beauty. The Greeks, therefore, applied the celestial kind of love only to friendship and boy-love, never to the love between men and women. Sergi finds the cause of love in the stimuli of the reproductive organs, and in the senses of touch and temperature.