Under certain circumstances some Catholic theologians have permitted a married woman to masturbate. Thus, the Jesuit theologian, Gury, asserts that the wife does not sin "_quæ se ipsam tactibus excitat ad seminationem statim post copulam in quâ vir solus seminavit_." This teaching seems to have been misunderstood, since ethical and even medical writers have expended a certain amount of moral indignation on the Church whose theologians committed themselves to this statement. As a matter of fact, this qualified permission to masturbate merely rests on a false theory of procreation, which is clearly expressed in the word _seminatio_. It was believed that ejaculation in the woman is as necessary to fecundation as ejaculation in the man. Galen, Avicenna, and Aquinas recognized, indeed, that such feminine semination was not necessary; Sanchez, however, was doubtful, while Suarez and Zacchia, following Hippocrates, regarded it as necessary. As sexual intercourse without fecundation is not approved by the Catholic Church, it thus became logically necessary to permit women to masturbate whenever the ejaculation of mucus had not occurred at or before coitus. The belief that the emission of vaginal mucus, under the influence of sexual excitement in women, corresponded to spermatic emission, has led to the practice of masturbation on hygienic grounds. Garnier (_Célibat_, p. 255) mentions that Mesué, in the eighteenth century, invented a special pessary to take the place of the penis, and, as he stated, effect the due expulsion of the feminine sperm.