human
mind. We speak of the laws of association, but this is an expression
which is confusing, for the phenomenon itself is of the most capricious
and uncertain sort. It may be briefly described as follows. The simplest
case of association is that of sense. When we see or hear separately
one of two things, which we have previously seen or heard together, the
occurrence of the one has a tendency to suggest the other. So the sight
or name of a house may recall to our minds the memory of those who once
lived there. Like may recall like and everything its opposite. The parts
of a whole, the terms of a series, objects lying near, words having
a customary order stick together in the mind. A word may bring back a
passage of poetry or a whole system of philosophy; from one end of the
world or from one pole of knowledge we may travel to the other in an
indivisible instant. The long train of association by which we pass from
one point to the other, involving every sort of complex relation, so
sudden, so accidental, is one of the greatest wonders of mind...This
process however is not always continuous, but often intermittent: we can
think of things in isolation as well as in association; we do not mean
that they must all hang from one another. We can begin again after an
interval of rest or vacancy, as a new train of thought suddenly arises,
as, for example, when we wake of a morning or after violent exercise.
Time, place, the same colour or sound or smell or taste, will often
call up some thought or recollection either accidentally or naturally
associated with them. But it is equally noticeable that the new thought
may occur to us, we cannot tell how or why, by the spontaneous action of
the mind itself or by the latent influence of the body. Both science and
poetry are made up of associations or recollections, but we must observe
also that the mind is not wholly dependent on them, having also the
power of origination.

There are other processes of the mind which it is good for us to study
when we are at home and by ourselves,--the manner in which thought
passes into act, the conflict of passion and reason in many stages, the
transition from sensuality to love or sentiment and from earthly love to
heavenly, the slow and silent influence of habit, which little by little
changes the nature of men, the sudden change of the old nature of man
into a new one, wrought by shame or by some other overwhelming impulse.
These are the greater