`full of industrious, honest people, and were it united would be the greatest power that ever was in the world.' He was greatly impressed with the beauties of the Rhine, though not anticipating the ecstasies of `Childe Harold.' These two expeditions were, he says, almost the only interruptions which his studies had received. He returned with increased experience, and `master of near a thousand pounds.'
His mother probably died (Burton, i. 191) during his last journey. In 1749 Hume returned to Ninewells. The essays published or written about this period completed Hume's contributions to philosophy. In April 1748 appeared his 'Philosophical Essays concerning the Human Understanding, by the Author of " Essays," &c.' This gave the first part of an intended recast of the unfortunate 'Treatise.' It included also the 'Essay upon Miracles,' which (or an early draft of which) he had thought of publishing in the `Treatise,' but had withheld from fear of giving offence. The `Philosophical Essays,' in spite of this challenge to the orthodox, attracted little notice; and Hume, upon returning from Turin, found the literary world entirely occupied with Conyers Middleton's `Free Enquiry.' His books, however, were now beginning to make a mark. A third edition of the moral and political essays appeared in the following November, to which Hume for the first time added his name, thus acknowledging also the `Philosophical Essays,' which reached a second edition in 1751. This had been kept back by his publisher, Millar, for some time `on account of the earthquakes,' which at the beginning of the year had caused a temporary fit of superstition. Besides these Hume published at the end of 1751 his `Enquiry concerning the Principles of Morals,' corresponding to the third volume of the `Treatise,' and which was, in his own opinion, `incomparably the best of all his writings.' It came, however, he adds, `unnoticed and unobserved into the world.' It was followed in 1752 by the 'Political Discourses.' This, he says, was the only work of his which succeeded upon its first publication. It attracted notice abroad as well as at home, and was translated into French by Eléazar Mauvillon in 1753, and by the Abbé Le Blanc in 1754. Le Blanc's translation passed through several editions, and Hume became an authority in France, where the rising school of economists was stimulated by his clear and original expositions. Adam Smith profited by his friend's arguments, to which he may possibly have contributed suggestions (see Haldane, Adam Smith, p. 20). Hume's rising reputation was now established in a wide circle. Besides his contributions to philosophical, political, and economical questions, he had also written some remarkable essays upon theology. His `Dialogues concerning Natural Religion' were written by 1751 (Burton, i. 331), but suppressed at the time by his friend's advice. In 1757 he published `Four Dissertations,' of which the first was his `Natural History of Religion.' From a letter to Millar previous to 1755 (ib. i. 421) it seems that he had kept this by him `for some years.' He mentions in the same letter `Some Considerations previous to Geometry and Natural Philosophy,' which may have been a recast of the corresponding part of the `Treatise' (bk. i. pt. ii.), but were suppressed, he says, on account of some defect either the logic or the perspicuity. The second dissertation, `upon the Passions,' is extracted from the `Treatise.' The third is upon tragedy, and the fourth, upon the `Standard of Taste,' replaces two upon `Suicide' and the `Immortality of the Soul' (written apparently between 1755 and 1757), which after being printed as parts of the volume were suppressed for the time (see Hume's letter to Strahan, Hill, p. 230; and Grose in Hume's Works, iii. 60-72). The book was dedicated to Home, author of 'Douglas,' the dedication being at first suppressed for fear of injuring Home's reputation as a minister but restored (in some copies) when he resigned his living. The book, says Hume, `made a rather obscure entry,' except that Hurd wrote a scurrilous pamphlet agains' it, which gave him some consolation for its `otherwise indifferent reception.' The pamphlet, as Hume suspected (Burton, ii. 35), was substantially written by Warburton, although called a letter to Warburton, and ascribed to `a gentleman of Cambridge,' in order to suggest Hurd as the author.
Hume's speculative writings (except the two suppressed essays on `Suicide' and `Immortality') were thus all written by 1751. Some surprise has been expressed that he should have now abandoned philosophy for history. Sufficient causes, however, may be easily suggested. His early disappointment at the failure of the `Treatise' developed into a sort of aversion to his unlucky offspring. In the advertisement, which seems to have been separately published before his death (see Hill, p. 302), to a posthumous edition of his 'Essays' (1777), he complained that controversialists had confined their attacks to his crude early treatise, and desires that in the future the `Essays' `may alone be regarded as containing his philosophical sentiments and principles.' In letters written in later life he