David Hartley

David Hartley (21 June 1705 to 28 August 1757) was an English physician and philosopher, the founder of the Associationist school of psychology. Born near Halifax in Yorkshire and educated at Bradford Grammar School and Jesus College, Cambridge, he practised medicine and campaigned for smallpox inoculation. His major work, Observations on Man, His Frame, His Duty, and His Expectations (1749), proposed that a single law of association explains memory, emotion, reasoning and voluntary action. Like Locke he held that the mind begins as a blank slate, and he tied mental life to vibrations of the nerves, which he explained with a subtle ether in the manner of Newton. On the free will question he was a determinist, and he extended his account to animals, holding that they differ from humans in degree and not in kind. Joseph Priestley was his chief advocate.