whence ariseth barrenness in women, and impotency in men?

the physicians maintain, that sterility in women can arise from the womb; for if it be after any ways thus affected, there will be a barrenness — if it be more condensed, or more thin, or more hardened, or more callous, or more carneous; or it may be from languor, or from an atrophy or vicious condition of body; or, lastly, it may arise from a twisted or distorted position. diocles holds that the sterility in men ariseth from some of these causes — either that they cannot at all ejaculate any sperm, or if they do, it is less than nature doth require, or else there is no generative faculty in the sperm, or the genital members are flagging; or from the obliquity of the yard. the stoics attribute the cause of sterility to the contrariant qualities and dispositions of those who lie with one another; but if it chance that these persons are separated, and there happen a conjunction of those who are of a suitable temperament, then there is a commixture according to nature, and by this means an infant is formed.