The orphaned son of an Anglican clergyman, David Hartley (1705–57) was originally destined for holy orders. Declining to subscribe to the Thirty-Nine Articles, he turned to medicine and science yet remained a religious believer. This, his most significant work, provides a rigorous analysis of human nature, blending philosophy, psychology and theology. First published in two volumes in 1749, Observations on Man is notable for being based on the doctrine of the association of ideas. It greatly influenced scientists, theologians, social reformers and Samuel Taylor Coleridge, who named his eldest son after Hartley, had his portrait painted while holding a copy. In Volume 1, Hartley utilises Newtonian science in his observations, presenting his theory of 'vibrations'. Volume 2 is particularly concerned with human morality and the duty and expectations of mankind. Hartley is keen to show that scientific observation is not necessarily in conflict with religious conviction.
The son of an Anglican clergyman, David Hartley was born in 1705 in the vicinity of Halifax, Yorkshire. His mother died three months after his birth, and his father when David was fifteen. After receiving his B.A. and M.A. from Jesus College, Cambridge, Hartley practiced medicine in Bury St. Edmunds (1730–35), London (1735–42), and Bath, where he died on 28 August 1757.
He married twice: in 1730, firstly to Alice Rowley, who died in 1731 giving birth to their son David (1731–1813); and in 1735, Elizabeth Packer (1713–78), despite the opposition of her very wealthy family. The couple had two children, Mary (1736–1803) and Wincombe Henry (1740–94). Although severely afflicted with bladder stones, Hartley lived a full and active life: he practiced medicine, engaged in mathematical research, sought a cure for “the stone,” devoted himself to intellectual and philanthropic projects, and wrote the Observations on Man.