David Hartley 1705-57, English physician and philosopher, founder of associational psychology. In his Observations on Man (2 vol., 1749) he stated that all mental phenomena are due to sensations arising from vibrations of the white medullary substance of the brain and spinal cord. He conceived the whole mind as resulting from the association of simple sensations. See associationism .

Hartley, David (1705–57), practised as a physician. In his Observations on Man, His Frame, His Duty, and His Expectations (1749), he repudiated the view of Shaftesbury and Hutcheson that the ‘moral sense’ is instinctively innate in us, and attributed it to the association of ideas. From this association of the ideas of pain and pleasure with certain actions, he traces the evolution of the higher pleasures out of the lower, until the mind is carried to ‘the pure love of God, as our highest and ultimate perfection’. With this psychological doctrine he combined a physical theory of ‘vibrations’ or ‘vibratiuncles’ in the ‘medullary substance’ of the brain. This theory was popularized by Joseph Priestley in Lectures on Oratory and Criticism and influenced the development of critical theory up to the time of Coleridge, who named his first son Hartley in honour of the philosopher, and many of whose poems show that he took the theory of association in a touchingly literal sense; indeed, it considerably influenced the Romantic view of man's relationship with the natural world. (See Romanticism.)

David Hartley

The British physician and philosopher David Hartley (1705-1757) is often referred to as one of the fathers of physiological psychology.

David Hartley, the son of a British clergyman, was born on Aug. 30, 1705. He received a private education before attending Cambridge, where he earned a bachelor's degree in 1726 and a master's degree in 1729. Although he intended to follow his father into the clergy, Hartley's disagreement with certain speculative doctrines adhered to by the Church of England prevented him from doing so. It did not, however, prevent him from remaining a lifelong member and defender of the Church or from writing on the subjects of theology and morals, as well as medicine and psychology. Forced to seek a new profession, Hartley turned to medicine and enjoyed considerable success.

Often the major contributions of self-effacing men are known best to those who come after them. Hartley's reputation as one of the founding fathers of the science of psychology rests on his two-volume work, Observations on Man, published, almost unnoticed, in 1749. Volume 2 deals with theology, and though of great importance to its author, it is of historical significance only as an example of the conviction held by many 18th-century scientists that there was no necessary conflict between science and revealed religion. Volume 1 is a systematic description of the emergence of highly complex emotional and mental states out of simple physical sensation.

Hartley's psychology can best be summarized under the twin headings of physiological determinism and associationism. All ideas and emotions are merely the coming together, or association, of various separate ideas which in turn can be traced to individual sensations that have been transmitted along the various nerves by a process of physical vibrations.

Hartley's private life was relatively uneventful: twice married, he fathered a number of children. Though he made little impression on the contemporary world at large, he communicated with many first-rate English minds of his day. In every way a gentleman, he was a kindly and expert doctor, well versed in subjects as diverse as shorthand and poetry and mathematics, devoutly religious, well organized and methodical though neither pedantic nor coldly efficient, and loved and admired by all who knew him. Hartley died at Newark, London, where he had practiced medicine, on Aug. 28, 1757.

Further Reading

The Transactions of the Halifax Antiquarian Society (1938-1939) contains a series of letters from Hartley to John Lister. These letters include personal information and show his interest in theological matters as well as algebra and shorthand. A facsimile of the first edition of Hartley's Observations on Man, edited by Theodore L. Huguelet (1966), contains a 12-page introduction which discusses Hartley's influence and life. □