mage of his savage appearance over the auditory-visual fibers. It is
clear, however, that, given any one of the elements of the entire
situation back, the rest are potentially possible to us, and any one may
serve as a "cue" to call up all the rest. Whether, given the starting
point, we get them all, depends solely on whether the paths are
sufficiently open between them for the current to discharge between
them, granting that the first experience made sufficient impression to
be retained.

Since this simple illustration may be made infinitely complex by means
of the millions of fibers which connect every center in the cortex with
every other center, and since, in passing from one experience to another
in the round of our daily activities, these various areas are all
involved in an endless chain of activities so intimately related that
each one can finally lead to all the others, we have here the machinery
both of retention and of recall--the mechanism by which our past may be
made to serve the present through being reproduced in the form of memory
images or ideas. Through this machinery we are unable to escape our
past, whether it be good or bad; for both the good and the bad alike are
brought back to us through its operations.

When the repetition of a series of acts has rendered habit secure, the
association is relatively certain. If I recite to you A-B-C-D, your
thought at once runs on to E, F, G. If I repeat, "Tell me not in
mournful numbers," association leads you to follow with "Life is but an
empty dream." Your neurone groups are accustomed to act in this way, so
the sequence follows. Memorizing anything from the multiplication table
to the most beautiful gems of poetic fervor consists, therefore, in the
setting up of the right associative connections in the brain.

ASSOCIATION IN THINKING.--All thinking proceeds by the discovery or
recognition of relations between the terms or objects of our thought.
The science of mathematics rests on the relations found to exist between
numbers and quantities. The principles and laws of natural science are
based on the relations established among the different forms of matter
and the energy that operates in this field. So also in the realm of
history, art, ethics, or any other field of human experience. Each fact
or event must be linked to other facts or events before it possesses
significance. Association therefore lies at the foundation of all
thinking, whether that of the