the structure of the human body, we shall find, that this security is very difficult to be attained on our part; and that since, in the copulation of the sexes, the principle of generation goes from the man to the woman, an error may easily take place on the side of the former, though it be utterly impossible with regard to the latter.  From this trivial and anatomical observation is derived that vast difference betwixt the education and duties of the two sexes.

Were a philosopher to examine the matter a priori, he would reason after the following manner.  Men are induced to labour for the maintenance and education of their children, by the persuasion that they are really their own; and therefore it is reasonable, and even necessary, to give them some security in this particular.  This security cannot consist entirely in the imposing of severe punishments on any transgressions of conjugal fidelity on the part of the wife; since these public punishments cannot be inflicted without legal proof, which it is difficult to meet with in this subject.  What restraint, therefore, shall we impose on women, in order to counter-balance so strong a temptation as they have to infidelity?  There seems to be no restraint possible, but in the punishment of bad fame or reputation; a punishment, which has a mighty influence on the human mind, and at the same time is inflicted by the world upon surmizes, and conjectures, and proofs, that would never be received in any court of judicature.  In order, therefore, to impose a due restraint on the female sex, we must attach a peculiar degree of shame to their infidelity, above what arises merely from its injustice, and must bestow proportionable praises on their chastity.

But though this be a very strong motive to fidelity, our philosopher would quickly discover, that it would not alone be sufficient to that purpose.  All human creatures, especially of the female sex, are apt to over-look remote motives in favour of any present temptation:  The temptation is here the strongest imaginable:  Its approaches are insensible and seducing:  And a woman easily finds, or flatters herself she shall find, certain means of securing her reputation, and preventing all the pernicious consequences of her pleasures.  It is necessary, therefore, that, beside the infamy attending such licences, there should be some preceding backwardness or dread, which may prevent their first approaches, and may give the female sex a repugnance to all expressions, and postures, and liberties, that have an immediate relation to that enjoyment.

Such would be the reasonings of our speculative philosopher:  But I am persuaded, that if he had not a perfect knowledge of human nature, he would be apt to regard them as mere chimerical speculations, and would consider the infamy attending infidelity, and backwardness to all its approaches, as principles that were rather to be wished than hoped for in the world.  For what means, would he say, of persuading mankind, that the transgressions of conjugal duty are more infamous than any other kind of injustice, when it is evident they are more excusable, upon account of the greatness of the temptation?  And what possibility of giving a backwardness to the approaches of a pleasure, to which nature has inspired so strong a propensity; and a propensity that it is absolutely necessary in the end to comply with, for the support of the species?