THE LAWS OF THOUGHT AND THE RULES OF ACTION
IN a note, bearing the date of June 29, 1827, which has been preserved for us by his biographer Bowring, Bentham gives an abridged definition of the two principles of his doctrine: ' Association Principle. -- Hartley. The bond of connection between ideas and language: and between ideas and ideas. Greatest Happiness Principle. -- Priestley. Applied to every branch of morals in detail, by Bentham: a part of the way previously by Helvetius'.1 The linking up of the two principles that was thus brought about reveals with what matters Bentham and his friends were preoccupied at this period. They felt that their social system would be incomplete so long as it was not based on a psychology and was not completed by a system of ethics.
The Philosophical Radicals wished to make social science a rational science; they held that all social phenomena are reducible to laws, and that all the laws of the social world are in their turn explicable by the 'laws of human nature'. But the laws of human nature are themselves of two kinds: physical laws, the definition of which the economist and the jurist borrow from the physician, from the geologist and from the biologist, and psychological laws, whose very existence is still open to question. For many people question even the possibility of a scientific psychology, constituted on the pattern of the sciences of nature. The procedure which James Mill used to show that a scientific psychology is possible consisted in showing that it either existed already, or had begun to exist. According to him, Hartley had been the founder of it in the eighteenth century. Then the theories of Hartley had been completed by new discoveries. The part played by James Mill in the history of the new psychology is analogous, at all points, to the part played by Ricardo in the history____________________