"The diversity in the temperament of man, is natural, the necessary source of the diversity of passions, of his taste, of his ideas of happiness, of his opinions of every kind. Thus this same diversity will be the fatal source of his disputes--of his hatreds--of his injustice--every time he shall reason upon unknown objects, but to which he shall attach the greatest importance. He will never understand either himself or others, in speaking of a spiritual soul, or of immaterial substances distinguished from nature; he will, from that moment, cease to speak the same language, and he will never attach the same ideas to the same words. What then shall be the common standard that shall decide which is the man that thinks with the greatest justice? "Propose to a man to change his religion for yours, he will believe you a madman; you will only excite his indignation, elicit his contempt; he will propose to you, in his turn, to adopt his own peculiar opinions; after much reasoning, you will treat each other as absurd beings, ridiculously opinionated, pertinaciously stubborn; and he will display the least folly who shall first yield. But if the adversaries become heated in the dispute, which always happens, when they suppose the matter important, or when they would defend the cause of their own self-love, from thence their passions sharpen, they grow angry, quarrels are provoked, they hate each other, and end by reciprocal injury. It is thus that for opinions, which no man can demonstrate, we see the Brachman despised; the Mahomedan hated; the Pagan held in contempt; that they oppress and disdain each with the most raucorous animosity: the Christian burns the Jew at what is called an _Auto-da-fe_, because he clings to the faith of his fathers; the Roman Catholic condemns the Protestant to the flames, and makes a conscience of massacreing(sp.) him in cold blood; this re-acts in his turn; sometimes the various sects of Christians league together against the incredulous Turk, and for a moment suspend their own bloody disputes that they may chastise the enemies to the true faith: then, having glutted their revenge, return with redoubied fury, to wreak over again their infuriated vengeance on each other." The thirteenth chapter argues as follows, against the doctrine of the immortality of the soul and a future state:--