g to Mill, can we ever calculate with
security what undiscoverable conditions may suddenly bring about an
unexpected event contrary to previous experience. The uniformity of
Nature, as Mr. Stephen remarks, is thus made exceedingly precarious;
and to the practical intelligence, which looks for some basis that
cannot be argued about, there is still something to be said for
Intuition. And when Mill, still in search of some precise formula,
undertook to interpret persistent sequences by his theory of Real
Kinds possessing an indeterminate number of coherent properties--so
that our belief in the invariable blackness of crows is justified as a
collocation of these visible properties--he merely throws the problem
of Causation farther backward. We have to be content with direct
observation of phenomena that can be classified as co-existent; we can
perceive that things accompany each other, but we can never be sure
that they follow each other, as they appear to do.

It may be doubted whether Mill's treatment of these problems has
materially affected subsequent psychological speculation, which has
since taken different and deeper courses. His main objective was
social and political.

'The notion,' he has written, 'that truths external to the mind may be
known by intuition, or consciousness, independently of observation and
experience, is, I am persuaded, in these times the great intellectual
support of false doctrines and bad institutions.' In confounding the
metaphysicians, and eliminating all mysterious assumptions or axioms,
he aimed at clearing the ground for a demonstrable science of
character, and to establish the great principle that character can be
indefinitely modified. The way is thus opened to questions of conduct,
to positive remedies for social and political evils which, as they
have been generated and fostered by external circumstances, can be
removed by a change of those circumstances.

'The greatest problems of the time were either economical or
closely connected with economical principles. Mill had followed the
political struggles with the keenest interest; he saw clearly their
connection with underlying social movements; and he had thoroughly
studied the science--or what he took to be the science--which must
afford guidance for a satisfactory working out of the great
problems. The Philosophical Radicals were deserting the old cause,
and becoming insignificant as a part