It is not possible to lay down a general rule with regard to the frequency of sexual intercourse, notwithstanding the earnestness with which religious zealots, physicians, and moral teachers have in all ages endeavored to determine how often it was proper for a man to cohabit with his wife. The rules that have been prescribed by the various authorities had in view, for the most part, the protection of the wife from excessive demands on the part of her husband; sometimes, however, by the establishment of a minimum period, a certain amount of sexual gratification was secured to the wife; finally, also, the generation of a healthy posterity had to be taken into consideration. _Ribbing_, however, justly observes: “Sexual intercourse results from a natural impulse, and he whose senses are unimpaired, and who has learned, at the same time, amid the tumult of his sensations, to preserve proper consideration for his wife—such a man runs little danger of making any mistake. In opposition to the opinion of many, I regard it as entirely right and reasonable that husband and wife should have intercourse whenever physically and mentally impelled to that act. Nor do I see any reason why, during the first period in which they are able to enjoy without intermission the pleasures of sexual intercourse, they should, in accordance with any theory whatever, impose on themselves further restraints than those demanded by care for their physical and mental health. The touchstone of marital hygiene is this, that on the day following intercourse both husband and wife should feel perfectly fresh, vigorous, and lively, alike in body and mind—even more so, perhaps, than on other days. In the absence of such feelings, we may feel assured of the occurrence of sexual excesses.” The same author quotes a saying of _Pomeroy’s_: “We may quaff the nectar as freely as we will—nature herself mixes the draught and holds the goblet to our lips; if, however, we drink too much, she first dilutes the draught with water, later adds gall, and ultimately perhaps deadly poison.” The occupation, trade, or profession, and the nutritive condition and physical constitution of the married pair, have an important bearing on the frequency with which, without detriment to health, cohabitation is permissible. The rules of the Hebrew Talmud already take these circumstances into account, ordering as they do that young and powerful men not engaged in any regular occupation shall have intercourse with their wives daily; manual labourers, on the other hand, once a week only; whilst brain-workers, finally, or those whose work is extremely arduous, should allow an interval of one or more months to elapse between the acts of intercourse. _Acton_ also prescribes that in the case of brain-workers and of those manual workers whose labours are exhausting, intercourse must not occur more frequently than once every week or ten days.