This ideogenetic question was long ago put forward in Greek philosophy (Stoicism, Epicureanism) and further developed to the full by the British Sensualists (John Locke, David Hume) and the British Associationists (Thomas Brown, David Hartley, Joseph Priestley). In the 19th century it was very much taken up by the Positivists (Auguste Comte, Herbert Spencer, Hippolyte Taine, Émile Littré)[2][3]