# A Critical Dictionary of English Literature/Hartley, David, M.D.

​Hartley, David, M.D., 1705-1757, a native of Armley, Yorkshire, was educated at Jesus College, Cambridge, of which he became Fellow. He settled as a physician first at Newark, afterwards at Bury-St.-Edmund’s, subsequently at London, and finally at Bath. He pub. some tracts upon Mrs. Stephens’s famous medicine for the stone,—of which he was a victim,—and some other professional treatises, but is best known by his Observations on Man, his Frame, his Duty, and his Expectations, Lon., 1749, 2 vols. 8vo. Repub. by his son, 1791, 4to, with Notes and Additions, from the German of H. A. Pistorius, Rector of Poseritz, in the Island of Rugen, and a sketch of the Life and Character of Dr. Hartley. Again, with additions, by Dr. Joseph Priestley, 1801, 3 vols. 8vo.
“This is the most valuable edition of this excellent work.”—Dr. Priestley.
In 1775, 8vo, appeared Hartley’s Theory of the Human Mind, on the Principle of the Association of Ideas; with Essays relating to the Subjects of it, by Joseph Priestley, LL.D. Again, 1790, 8vo. Hartley’s philosophical theory
“Regards the brain, the nerves, and the spinal marrow, as the direct instruments of sensation. External objects, he conceives, excite vibrations in these medullary cords, which vibrations, once communicated, are kept up by a certain elastic fluid called ether. After a sufficient repetition of these vibrations, the sensations leave behind them types and images of themselves. Frequent repetition excites association, and association in its turn imparts to any one idea the power of exciting all the related ideas,—a power which belongs likewise to the vibratiundes and their miniature images. Upon this principle and theory of association, he attempts to account for all the phenomena of the mental constitution of man.”
The hypothesis of vibrations, it is well known, has been completely overthrown by Haller’s demonstration that there can be no such thing as vibrations in the nervous system. Priestley endeavours to prove that Hartley was a materialist like himself; but Hartley “dreaded nothing so much” as this imputation, though certainly he is to be read with caution, and cannot be proposed as a sound guide in theology. As regards his obligations as a philosopher to Newton, Locke, Gay, and even to Aristotle, and how far he concurs with Hobbes, can be ascertained by an examination of the authorities referred to below. As an expositor of the “Law of Association”—we use the term Law not without scruple—Hartley is certainly entitled to some credit, and he has been fully paid. We quote some opinions respecting his philosophical speculations as displayed in the Observations on Man:
“Something was done in this field of knowledge by Descartes, very much by Mr. Locke, but most of all by Dr. Hartley, who has thrown more useful light upon the theory of the mind, than Newton did upon the theory of the natural world.”—Dr. Priestley: Remarks on Reid, Beattie, and Oswald, 1774.
“Johnson, one day, observing a friend of his packing up two volumes of Observations on Man, written by this good and great man, to take into the country, said, ‘Sir, you do right to take Dr. Hartley with you; Priestley said of him, that he had learned more from Hartley than from any book he had ever read, except the Bible.’”—Boswell's Life of Johnson.
“Hartley has investigated the principle of Association more deeply, explained it more accurately, and applied It more usefully, than even his great and venerable predecessor, Mr. Locke.”—Dr. Parr: Serm. on Education, 1774.
“The writer who has built most upon Hobbes, and may be reckoned, in a certain sense, the commentator, if he who fully explains and developes a system may deserve that name, was Hartley.”—Hallam’s Lit. Hist. of Europe, q. v.
“That there is great value to be attached to much which Hartley has drawn from the law of association, and that he has afforded an explanation of many phenomena, before very imperfectly understood, cannot be denied. The very ardour, however, with which he threw himself into his system, and the very closeness with which he analyzed the facts in the case, necessarily imparted a one-sidedness to his philosophy, and led to the neglect of some other facts equally important.”—Morell’s Hist. of Mod. Philos.
“It is the first attempt to join the study of intellectual man to that of physical man.”—Cousin’s Hist. of Mod. Philos., O. W. Wight’s Trans.
Cousin is a high authority,—but does he not forget philosophic caution when he styles Hartley’s the “first attempt”? We offer no counter-statement, but we think it exceedingly hazardous to pretend to designate “the first attempt” in any branch of human speculation. We have ventured to hint some doubts respecting the extraordinary ​merit which has been claimed for Hartley’s speculations; and, if we err here, we err with great examples:
“The capital fault of Hartley is that of a rash generalization, which may prove imperfect, and which is at least premature. All attempts to explain or instruct by this principle have hitherto been unavailing. Many of the most important processes of reasoning have not hitherto been accounted for by it.”—Sir James Mackintosh: 2d Prelim. Dissert. to Encyc. Brit.
“The intentions of both [Bonnet and Hartley] are allowed, by those who best knew them, to have been eminently pure and worthy; but it cannot be said of either, that his metaphysical writings have contributed much to the instruction or to the improvement of the public. On the contrary, they have been instrumental in spreading a set of speculative tenets very nearly allied to that sentimental and fantastical modification of Spinozism which for many years past has prevailed so much and produced such mischievous effects in some parts of Germany.”—Dugald Stewart: 1st Prelim. Dissert. to Encyc. Brit.
Bishop Watson reprinted in his Collection of Tracts one on the Truth of the Christian Religion, prefaced by the remark:
“This tract is printed from the second volume of Dr. Hartley’s Observations on Man; it is written with singular closeness of thought, and to be well understood must be read with great attention.”—Bishop Watson.
Consult authorities cited above; and see also Life by his son, prefixed to his Observations on Man, ed. 1791, 4to; Reid’s Essays on the Intellectual Powers; Blakey’s Hist. of Mod. Philos.; Dr. E. Williams’s Christian Preacher, ed. 1843, p. 337; Watson’s Hist. of Halifax; Cunningham’s Biog. Hist. of England; Chalmers’s Biog. Dict.