It is thus a result of the complexity of the sexual mechanism in women that the whole attitude of a woman toward the sexual relationship is liable to be affected disastrously by the husband's lack of skill or consideration in initiating her into this intimate mystery. Normally the stage of apparent repulsion and passivity, often associated with great sensitiveness, physical and moral, passes into one of active participation and aid in the consummation of the sexual act. But if, from whatever cause, there is partial arrest on the woman's side of this evolution in the process of courtship, if her submission is merely a mental and deliberate act of will, and not an instinctive and impulsive participation, there is a necessary failure of sexual relief and gratification. When we find that a woman displays a certain degree of indifference in sexual relationships, and a failure of complete gratification, we have to recognize that the fault may possibly lie, not in her, but in the defective skill of a lover who has not known how to play successfully the complex and subtle game of courtship. Sexual coldness due to the shock and suffering of the wedding-night is a phenomenon that is far too frequent.[172] Hence it is that many women may never experience sexual gratification and relief, through no defect on their part, but through the failure of the husband to understand the lover's part. We make a false analogy when we compare the courtship of animals exclusively with our own courtships before marriage. Courtship, properly understood, is the process whereby both the male and the female are brought into that state of sexual tumescence which is a more or less necessary condition for sexual intercourse. The play of courtship cannot, therefore, be considered to be definitely brought to an end by the ceremony of marriage; it may more properly be regarded as the natural preliminary to every act of coitus. Tumescence is not merely a more or less essential condition for proper sexual intercourse. It is probably of more fundamental significance as one of the favoring conditions of impregnation. This has, indeed, been long recognized. Van Swieten, when consulted by the childless Maria Theresa, gave the opinion "Ego vero censeo, vulvam Sacratissimæ Majestatis ante coitum diutius esse titillandam," and thereafter she had many children. "I think it very nearly certain," Matthews Duncan wrote (_Goulstonian Lectures on Sterility in Woman_, 1884, p. 96), "that desire and pleasure in due or moderate degree are very important aids to, or predisposing causes of, fecundity," as bringing into action the complicated processes of fecundation. Hirst (_Text-book of Obstetrics_, 1899, p. 67) mentions the case of a childless married woman who for six years had had no orgasm during intercourse; then it occurred at the same time as coitus, and pregnancy resulted.