In the study of language, we perceive the same evidences of our intellectual advancement. By arranging the elements of speech according to the physical organs employed in their utterance, great light has been thrown on etymology, and in this way, affinities have been traced, first among languages, and through them among nations apparently unconnected. And as all language consists of _signs_ of our mental operations, the general principles of grammar have been sought in the laws of the mind; while language in turn, has been sometimes successfully invoked to explain those laws; and thus philology and mental philosophy have assisted in elucidating each other. This branch of philosophy (which treats of our mental faculties) has not indeed made as much progress as many others; for it admits not the discovery of new facts. But neither has _this_ been stationary. Great improvements have been made in analyzing its compound states; in separating its original from its derivative properties; in tracing many seemingly diverse operations to one simple principle. To be convinced of this improvement, we have only to regard the theory of associations as it now is, compared with the slight and vague notice of it by Locke; or advert to the opinions of the same eminent man on the foundation of morals. He maintained that there was no original propensity in mankind to approve one action as virtuous, and another as vicious; and that there was no practical principle which was approved or condemned by all nations. He even denied that parental affection, the strongest feeling in the maternal bosom, was an original feeling. He refers to the inventions of travellers in support of his theory, and was as credulous of the anomalous facts they related, as he was skeptical of innate propensities. Thus he says: "It is familiar among the Mingrelians, a people professing christianity, to bury their children alive without scruple; he asserts that the Caribbees were wont to fat and eat their own children;" and that a people of Peru who followed this practice, used, when by the course of nature they no longer had a prospect of more children to eat, "to kill and eat the mothers." A more intimate acquaintance with the people of this globe, and juster modes of reasoning, have dissipated these illusions; and if I mistake not, the laws of the mind will, in no distant day, be traced with an accuracy and precision little inferior to those which prevail in most branches of physics.