From a blind idea of the usefulness of such abstract science, my father had been desirous, and even pressing, that I should devote some time to the mathematics; nor could I refuse to comply with so reasonable a wish. During two winters I attended the private lectures of Monsieur de Traytorrens, who explained the elements of algebra and geometry, as far as the conic sections of the Marquis de l'Hopital, and appeared satisfied with my diligence and improvement. But as my childish propensity for numbers and calculations was totally extinct, I was content to receive the passive impression of my Professor's lectures, without any active exercise of my own powers. As soon as I understood the principles, I relinquished for ever the pursuit of the mathematics; nor can I lament that I desisted, before my mind was hardened by the habit of rigid demonstration, so destructive of the finer feelings of moral evidence, which must, however, determine the actions and opinions of our lives. I listened with more pleasure to the proposal of studying the law of nature and nations, which was taught in the academy of Lausanne by Mr. Vicat, a professor of some learning and reputation. But instead of attending his public or private course, I preferred in my closet the lessons of his masters, and my own reason. Without being disgusted by Grotius or Puffendorf, I studied in their writings the duties of a man, the rights of a citizen, the theory of justice (it is, alas! a theory), and the laws of peace and war, which have had some influence on the practice of modern Europe. My fatigues were alleviated by the good sense of their commentator Barbeyrac. Locke's Treatise of Government instructed me in the knowledge of Whig principles, which are rather founded in reason than experience; but my delight was in the frequent perusal of Montesquieu, whose energy of style, and boldness of hypothesis, were powerful to awaken and stimulate the genius of the age. The logic of De Crousaz had prepared me to engage with his master Locke and his antagonist Bayle; of whom the former may be used as a bridle, and the latter applied as a spur, to the curiosity of a young philosopher. According to the nature of their respective works, the schools of argument and objection, I carefully went through the Essay on Human Understanding, and occasionally consulted the most interesting articles of the Philosophic Dictionary. In the infancy of my reason I turned over, as an idle amusement, the most serious and important treatise: in its maturity, the most trifling performance could exercise my taste or judgment, and more than once I have been led by a novel into a deep and instructive train of thinking. But I cannot forbear to mention three particular books, since they may have remotely contributed to form the historian of the Roman empire. 1. From the Provincial Letters of Pascal, which almost every year I have perused with new pleasure, I learned to