Should it be asked, what proportion these two species of morality bear to each other?  I would answer, that this is a question, to which we can never give any precise answer; nor is it possible to reduce to numbers the proportion, which we ought to fix betwixt them.  One may safely affirm, that this proportion finds itself, without any art or study of men; as we may observe on many other occasions.  The practice of the world goes farther in teaching us the degrees of our duty, than the most subtile philosophy, which was ever yet invented.  And this may serve as a convincing proof, that all men have an implicit notion of the foundation of those moral rules concerning natural and civil justice, and are sensible, that they arise merely from human conventions, and from the interest, which we have in the preservation of peace and order.  For otherwise the diminution of the interest would never produce a relaxation of the morality, and reconcile us more easily to any transgression of justice among princes and republics, than in the private commerce of one subject with another.

SECT.  XII OF CHASTITY AND MODESTY

If any difficulty attend this system concerning the laws of nature and nations, it will be with regard to the universal approbation or blame, which follows their observance or transgression, and which some may not think sufficiently explained from the general interests of society.  To remove, as far as possible, all scruples of this kind, I shall here consider another set of duties, viz, the modesty and chastity which belong to the fair sex:  And I doubt not but these virtues will be found to be still more conspicuous instances of the operation of those principles, which I have insisted on.

There are some philosophers, who attack the female virtues with great vehemence, and fancy they have gone very far in detecting popular errors, when they can show, that there is no foundation in nature for all that exterior modesty, which we require in the expressions, and dress, and behaviour of the fair sex.  I believe I may spare myself the trouble of insisting on so obvious a subject, and may proceed, without farther preparation, to examine after what manner such notions arise from education, from the voluntary conventions of men, and from the interest of society.

Whoever considers the length and feebleness of human infancy, with the concern which both sexes naturally have for their offspring, will easily perceive, that there must be an union of male and female for the education of the young, and that this union must be of considerable duration.  But in order to induce the men to impose on themselves this restraint, and undergo chearfully all the fatigues and expences, to which it subjects them, they must believe, that the children are their own, and that their natural instinct is not directed to a wrong object, when they give a loose to love and tenderness.  Now if we examine