This difference of judgment regarding extra-conjugal sexual intercourse on the part of husband and wife respectively, depends entirely upon the perfectly sound experience that =simultaneous= cohabitation on the part of a woman with several men obscures paternity, and therewith the foundations of the family, quite apart from a not uncommon physical injury to the child. This =natural= difference between man and woman, in respect of sexual intercourse and its consequences, will always endure. A man can simultaneously cohabit with two women without thereby interfering with the formation of a family; but a woman cannot with similar impunity cohabit with two men. It is possible that the demand for the virgin intactness of the wife at the time of marriage is based upon the old experience that by sexual intercourse, and still more by the first conception, certain far-reaching specific changes are induced in the feminine organism, so that the first man impregnates the feminine being for ever in his own sense, and even transmits his influence to children of a second male progenitor. (_Cf._ in this connexion G. Lomer, “Love and Psychosis,” p. 37.) “It is not the brutality of man,” says Eberstadt, “which has imposed a higher responsibility upon woman; Nature herself has done this. Nature has endowed man and woman differently in respect of the consequences of sexual intercourse. The fruit of intercourse is entrusted to the woman alone. Now, one who has special responsibilities has also special duties. Certain breaches of conjugal responsibility are more sternly condemned when committed by the man; certain others--especially such as concern care for the offspring--are more severely judged in the wife. The relative positions in respect of sexual intercourse are different in man and in woman, for reasons which are physical and inalterable. Seduction, ill-treatment, abandonment of a wife, and adultery, are punished in the husband by law and custom. The wife, on the other hand, loses her honour =simply= on account of promiscuous and unregulated intercourse, because Nature herself forbids this intercourse if the material and spiritual tie between mother, father, and child is to persist.” In accordance with these considerations, Eberstadt holds fast to the demand for “=monandry=” on the part of the wife; he rejects on principle the idea of =sexual= equality between man and wife, and relegates the progressive development of marriage exclusively to the =spiritual= and =moral= provinces.