[Footnote 5: It is difficult to decide on madame du Châtelet's character. With regard to the immorality of her liaison with Voltaire, we will merely refer to the clever preface of the English editor to madame du Duffand's correspondence with Horace Walpole, in which the stale of society in that age is so well described; and only remark, that such was the system, that a devoted and enduring friendship for so great a man was considered highly respectable, even though that friendship militated against our stricter notions of social duties; it not being considered the business of any one to inquire into, or concern themselves with, a question that related only to the persons immediately implicated. With regard to madame du Châtelet's general character, she was unpopular through the vehemence of her temper, and even the ardour with which she devoted herself to study. She had several of the faults attributed to literary women, which arise from their not having the physical strength to go through great intellectual labour without suffering from nervous irritation In other respects she was evidently generous and sincere. Her judgment was sound; her common sense clear and steady. She was witty and vivacious, and had as much to bear from Voltaire's petulance, whimsicalness, and vehemence, as he from her more imperious temper.] [Footnote 6: When the correspondence was renewed between Frederic and Voltaire, they could not help alluding to the past, and their expressions show that each thought himself in the right. Voltaire says, "I am unutterably surprised when you write that I have spoken harshly to you. For twenty years you were my idol, '_je l'ai dit à la terre, au ciel, à Guzman même_;' but your trade of hero, and your situation of king, do not render the disposition tender: it is a pity, for your heart was made for kindness; and were it not for heroism and a throne, you would have been the most amiable man in the world." Frederic replied, with greater force, "I well know that I adored you as long as I thought you neither mischievous nor malicious: but you have played me so many tricks, of all kinds. Let us say no more; I have pardoned you. After all, you have done me more good than ill. I am more amused by your works, than hurt by your scratches."] [Footnote 7: Lettres de Madame du Deffand à Horace Walpole, vol. II.] ROUSSEAU 1712-1778.