Conception is nothing but an action of the womb, by which the prolific seed is received and retained, that an infant may be engendered and formed out of it. There are two sorts of conception: the one according to nature, which is followed by the generation of the infant in the womb; the other false and wholly against nature, in which the seed changes into water, and produces only false conceptions, moles, or other strange matter. Now, there are three things principally necessary in order to a true conception, so that generation may follow, viz., without diversity of sex there can be no conception; for, though some will have a woman to be an animal that can engender of herself, it is a great mistake; there can be no conception without a man discharge his seed into the womb. What they allege of pullets laying eggs without a cock's treading them is nothing to the purpose, for those eggs should they be set under a hen, will never become chickens because they never received any prolific virtue from the male, which is absolutely necessary to this purpose, and is sufficient to convince us, that diversity of the sex is necessary even to those animals, as well as to the generation of man. But diversity of sex, though it be necessary to conception, yet it will not do alone; there must also be a congression of the different sexes; for diversity of sex would profit little if copulation did not follow. I confess I have heard of subtle women, who, to cover their sin and shame, have endeavoured to persuade some peasants that they were never touched by man to get them with child; and that one in particular pretended to conceive by going into a bath where a man had washed himself a little before and spent his seed in it, which was drawn and sucked into her womb, as she pretended. But such stories as these are only for such who know no better. Now that these different sexes should be obliged to come to the touch, which we call copulation or coition, besides the natural desire of begetting their like, which stirs up men and women to it, the parts appointed for generation are endowed by nature with a delightful and mutual itch, which begets in them a desire to the action; without which, it would not be very easy for a man, born for the contemplation of divine mysteries, to join himself, by the way of coition, to a woman, in regard to the uncleanness of the part and the action. And, on the other side, if the woman did but think of those pains and inconveniences to which they are subject by their great bellies, and those hazards of life itself, besides the unavoidable pains that attend their delivery, it is reasonable to believe they would be affrighted from it. But neither sex makes these reflections till after the action is over, considering nothing beforehand but the pleasure of the enjoyment, so that it is from this voluptuous itch that nature obliges both sexes to this congression. Upon which the third thing