Associated with the progress towards “love” of this sexual impulse enriched by sensory stimuli was a =preponderance=, a prevalence, of certain particular sensory stimuli. Herein are certainly to be found the beginnings of a spiritualization of purely animal instincts and impulses. The most important part in the amatory life of man is played, even at the present day, by the sense of touch, and by the two higher senses, sight and hearing, these two latter containing so many spiritual elements. The =sense of touch= is more widely extended in space than the other senses, and for this reason touch is quantitatively the most excitable of the senses. The stimulation of the sensory nerves of the skin, the enormous number of which suffices to explain the richness of sensation through the skin, experienced as touch, tickling, or slight pain, transmits very similar sensations to the voluptuous sensorium. The relationship between these various modes of sensation is confirmed by the fact that the terminals of the sensory nerves of the skin, the so-called corpuscles of Vater or Pacini, closely resemble in structure the corpuscles of Krause found on the glans penis and glans clitoridis, on the prepuce of the clitoris, the labia majora, and on the papillæ of the red margin of the lip. From this point of view, the entire skin may be regarded as a huge organ of voluptuous sensation, of which the skin of the external organs of conjugation is most strongly susceptible to stimulation. Mantegazza therefore describes sexual love as a higher form of tactile sensation. In human beings of a baser disposition love is no more than a touch. Between the chaste stroking of the hair and the violent storm of the sexual orgasm there is a quantitative, but not a qualitative difference. The sense of touch is a profoundly sexual sense, which at the present day plays much the same part as was in primitive times played by the sense of smell. “The skin,” says Wilhelm Bölsche, “became the great procurer, the dominant intermediary of love, for the multicellular animals, in which complete conjugation of the cell bodies had become impossible, so that their sexual gratification had to be obtained by distance-love, by contact-love. Thus the skin was the primitive area of voluptuous sensation, the arena of the supreme bodily triumph of this distance-love.”