English physician and philosopher. Hartley is best remembered for being the founder of associationist psychology. His Observations of Man: his Frame, his Duty, and his Expectations (1749) is a naturalistic attempt to provide an integrated theory of human nature. Hartley believed that the task of education was to bring about an association of private pleasure with the exercise of public benevolence and virtue. In the well-adjusted person there is a ‘ladder of pleasures’ with those of benevolence towards the top, because of their associations with various other kinds of pleasure. Hartley's thought significantly influenced the later generation of utilitarians such as James Mill.