ually effective in philosophy, and ever since
Locke, philosophy had meant psychology. The 'philosophy of the mind'
and the philosophy of the body may be treated as co-ordinate and
investigated by similar methods. In the physical sciences we come
ultimately to the laws of movement of their constituent atoms. In the
moral sciences we come in the same way to the study of 'ideas.' The
questions, How do ideas originate? and how are they combined so as to
form the actual state of consciousness? are therefore the general
problems to be solved. Hume had definitely proposed the problem.
Hartley had worked out the theory of association of ideas which Hume
had already compared[508] to the universal principle of gravitation in
the physical world; and had endeavoured to show how this might be
connected with physiological principles. Hartley's followers had been
content to dwell upon the power of association. Abraham Tucker,
Priestley, Erasmus Darwin, and Belsham represented this tendency, and
were the normal antagonists of Reid and Stewart. In France the
'ideologists' mainly followed Condillac, and apparently knew nothing
of Hartley. Mill, as his son testifies, had been profoundly influenced
by Hartley's treatise--the 'really master-production,' as he esteemed
it, 'in the philosophy of mind.'[509] Hartley's work, as the younger
Mill thought, and the elder apparently agreed, was very superior to
the 'merely verbal generalisation of Condillac.' James Mill, however,
admired Condillac and his successors. In his article upon education,
Mill traces the association theory to Hobbes, Locke, and Hume, the
last of whom, he says, was succeeded by the two 'more sober-minded'
philosophers, Condillac and Hartley; while he especially praises
Erasmus Darwin, Helvetius, and Cabanis. Mill, therefore, may be
regarded as an independent ally of the ideologists whose influence
upon Brown has been already noticed. Mill had not read Brown's
_Lectures_ when he began his _Analysis_, and after reading them
thought Brown 'but poorly read in the doctrine of association.'[510]
He had, however, read the essay upon causation, which he rather oddly
describes as 'one of the most valuable contributions to science for
which we are indebted to the last generation.'[511] He accepted
Brown's view _minus_ the 'intuition.'

The pith of Mill's book is thus determined. His aim is to give a
complete analysis of mental phenomena, and therefore to resolve those
phenomena into