We however perceive that some things become immediately the cause of a great change in quality, as is evident in wine. For when it is drank abundantly, it makes men at first more cheerful, but afterwards more insane and indecorous. But men are ignorant of those things which do not exhibit a power of this kind; though every thing that is eaten is the cause of a certain peculiar disposition. Hence it requires great wisdom, to be able to know and perceive, what kind and what quantity of food ought to be used. This science, however, was at first unfolded by Apollo and Pæon; but afterwards by Esculapius and his followers. With respect to generation also, the Pythagoreans are said to have made the following observations. In the first place, they thought it necessary to guard against what is called untimely [offspring]. For neither untimely plants, nor animals, are good; but prior to their bearing fruit, it is necessary that a certain time should intervene, in order that seeds and fruit may be produced from strong and perfect bodies. It is requisite, therefore, that boys and virgins should be accustomed to labors and exercises, and appropriate endurance, and that food should be given to them adapted to a life of labor, temperance, and endurance. But there are many things of this kind in human life, which it is better to learn at a late period, and among these is the use of venery. It is necessary, therefore, that a boy should be so educated, as not to seek after such a connexion as this, within the twentieth year of his age. But when he arrives at this age, he should use venery rarely. This however will be the case, if he thinks that a good habit of body is an honorable and beautiful thing. For intemperance and a good habit of body, are not very much adapted to subsist together in the same person. It is also said, that those laws were praised by the Pythagoreans, which existed prior to their time in Grecian cities, and which prohibited the having connexion with a woman who is a mother, or a daughter, or a sister, either in a temple, or in a public place. For it is beautiful and advantageous that there should be numerous impediments to this energy. These men also apprehended, as it seems, that preternatural generations, and those which are effected in conjunction with wanton insolence, should be entirely prevented from taking place; but that those should be suffered to remain, which are according to nature, and subsist with temperance, and which take place in the chaste and legal procreation of children.