Buckle has remarked on a contrast between Smith’s theory of morals and his theory of economics. In the first, sympathy is the premise, and he works out the principle of sympathy to its logical conclusions. In the _Wealth of Nations_, on the contrary, the word sympathy scarcely occurs. He assumes self-interest as the sole motive of the economic man, and works out all the consequences without troubling about that other-regarding principle which is the foundation and measure of morality, though he shows, it is true, that the motive of self-interest, if sufficiently enlightened, will result in the general good. Without denying that Buckle’s contention is suggestive, we may observe that Smith distinctly refuses to confine virtue to benevolence, and parts company on this very point from “the amiable system” of Hutcheson. “Regard to our own private happiness, and interest too, appear,” says he, “upon many occasions very laudable principles of action. The habits of economy, industry, discretion, attention, and application of thought are generally supposed to be cultivated from self-interested motives, and at the same time are apprehended to be very praiseworthy qualities, which deserve the esteem and approbation of everybody.”[13] Benevolence may perhaps be the sole principle of action in the Deity, but an imperfect creature like man must and ought often to act from other motives. To the third edition of the _Moral Sentiments_ (1767) was appended an essay on the formation of Languages and the different genius of original and compounded languages. It is the fruit of his philological studies, and contains no doubt the substance of lectures that he had read in Edinburgh and Glasgow. He starts with the proposition that names of objects, that is to say, nouns substantive, must have been the first steps toward the making of a language. Two savages who had never been taught to speak would naturally begin to make their mutual wants intelligible by uttering certain sounds, as cave, tree, fountain, whenever they wanted to denote particular objects. What was at first a proper name would thus be extended to similar objects, by the same law which leads us to call a great philosopher a Newton. Similarly, “a child that is just learning to speak calls every person who comes into the house its papa or its mamma.” Smith could call to mind a clown “who did not know the proper name of the river which ran by his own door.” It was “_the_ river.” This process of generalisation explains the formation of those classes and assortments called genera and species in the schools, “of which the ingenious and eloquent M. Rousseau of Geneva finds himself so much at a loss to account for the origin.”[14] In his account of the dual number, which he finds in all primitive and uncompounded languages, he says that in the rude beginnings of society, _one_, _two_, and _more_, might possibly be all the numerical distinctions which mankind would have any occasion to take notice of.