In Henry Home, Lord Kames, notwithstanding a temperament very different from his own, Reid found congenial companionship—a strong disposition to metaphysical speculation, a ready and accomplished if not deeply learned lawyer, and a considerable author. Kames was fourteen years his senior. Curiously, Henry Home’s closest early friendship was with David Hume. Thirty years before his friendship with Reid, he advised Hume about the _Treatise of Human Nature_, and had given the youth an introduction to Bishop Butler. ‘My opinions,’ David writes in 1737, ‘are so new, and even some terms I am obliged to make use of, that I could not propose, by any abridgment, to give my system an air of likelihood, or even to make it intelligible. I have had a greater desire of communicating to you a plan of the whole, that I believe it will not appear in public before the beginning of next winter. I am at present castrating my work, that is, cutting off its nobler parts, that is, endeavouring it shall give as little offence as possible. This is a piece of cowardice for which I blame myself. But I resolved not to be an enthusiast in philosophy while I was blaming other enthusiasms.’ It was thus that Hume wrote about the book which, even in its ‘castrated’ form, startled Reid in the manse at New Machar, and determined his whole intellectual life. In 1751 Home published _Essays on the Principles of Morality and Natural Religion_, on which Jonathan Edwards congratulated him in a letter to Dr. Erskine. Yet his speculations, and his association with the sceptic, raised a suspicion of his orthodoxy in the General Assembly.