I know not if your commodious scheme of philosophy has already adopted the maxims, which, it is said, are established in large towns, for the toleration of such places: but I hope, at least, you are not one of those who debase themselves so much as to put them in practice, under the pretext of I know not what chimerical necessity, that is known only to men of debauched lives; as if the two sexes were in this respect of a different constitution; and, that during absence or celibacy, a virtuous man is under a necessity of indulging himself in liberties which are denied to a modest woman. But if this error does not lead you to prostitutes, I am afraid it will continue to lead your imagination astray. Alas! if you are determined to be despicable, be so at least without pretext; and add not the vice of lying to that of drunkenness. All those pretended necessities have no foundation in nature, but in the voluntary depravation of the senses. Even the fond illusions of love are refined by a chaste mind, and pollute it only when the heart is first depraved. On the contrary, chastity is its own support; the desires constantly repressed accustom themselves to remain at rest, and temptations are only multiplied by the habit of yielding to them. Friendship has made me twice overcome the reluctance I had to write on such a subject, and this shall be the last time: for on what plea can I hope to obtain that influence over you, which you have refused to virtue, to love, and to reason? But I return to that important point, with which I began this letter; at one and twenty years of age you sent me, from the Valais, grave and judicious descriptions of men and things: at twenty-five you write me, from Paris, a pack of trifling letters, wherein good sense is sacrificed to a certain quaintness and pleasantry, very incompatible with your character. I know not how you have managed; but since you have resided among people of refined talents, yours appear to be diminished: you profited among clowns, and have lost by the wits. This is not, however, the fault of the place you are in, but of the acquaintance you have made: for nothing requires greater judgment than to make a proper choice in a mixture of the excellent and execrable. If you would study the world, keep company with men of sense, who have known it by long experience and observations made at leisure; not with giddy-headed boys, who see only the superficies of things, and laugh at what they themselves make ridiculous. Paris is full of sensible men, accustomed to reflection, and to whom every day presents a fertile field for observation. You will never make me believe that such grave and studious persons run about, as you do, from house to house, and from club to club, to divert the women and young fellows, and turn all philosophy into chit chat. They have too much dignity thus to debase their characters, prostitute their talents, and give a sanction by their example, to modes which they ought to correct. But,