If a biographical effort really endeavors to penetrate the understanding of the psychic life of its hero it must not, as happens in most biographies through discretion or prudery, pass over in silence the sexual activity or the sex peculiarity of the one examined. What we know about it in Leonardo is very little but full of significance. In a period where there was a constant struggle between riotous licentiousness and gloomy asceticism, Leonardo presented an example of cool sexual rejection which one would not expect in an artist and a portrayer of feminine beauty. Solmi[12] cites the following sentence from Leonardo showing his frigidity: "The act of procreation and everything that has any relation to it is so disgusting that human beings would soon die out if it were not a traditional custom and if there were no pretty faces and sensuous dispositions." His posthumous works which not only treat of the greatest scientific problems but also comprise the most guileless objects which to us do not seem worthy of so great a mind (an allegorical natural history, animal fables, witticisms, prophecies),[13] are chaste to a degree--one might say abstinent--that in a work of _belle lettres_ would excite wonder even to-day. They evade everything sexual so thoroughly, as if Eros alone who preserves everything living was no worthy material for the scientific impulse of the investigator.[14] It is known how frequently great artists found pleasure in giving vent to their phantasies in erotic and even grossly obscene representations; in contradistinction to this Leonardo left only some anatomical drawings of the woman's internal genitals, the position of the child in the womb, etc. It is doubtful whether Leonardo ever embraced a woman in love, nor is it known that he ever entertained an intimate spiritual relation with a woman as in the case of Michelangelo and Vittoria Colonna. While he still lived as an apprentice in the house of his master Verrocchio, he with other young men were accused of forbidden homosexual relations which ended in his acquittal. It seems that he came into this suspicion because he employed as a model a boy of evil repute.[15] When he was a master he surrounded himself with handsome boys and youths whom he took as pupils. The last of these pupils Francesco Melzi, accompanied him to France, remained with him until his death, and was named by him as his heir. Without sharing the certainty of his modern biographers, who naturally reject the possibility of a sexual relation between himself and his pupils as a baseless insult to this great man, it may be thought by far more probable that the affectionate relationships of Leonardo to the young men did not result in sexual activity. Nor should one attribute to him a high measure of sexual activity.