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 original thinker who is creating our sciences,
planning and executing the events of history, evolving a system of ethics, or
whether one is only learning these fields as they already exist by means of study.
Other things being equal, he is the best thinker who has his knowledge related
part to part so that the whole forms a unified and usable system.
Association and Action.—Association plays an equally important part in all our
motor responses, the acts by which we carry on our daily lives, do our work and
our play, or whatever else may be necessary in meeting and adapting ourselves
to our environment. Some sensations are often repeated, and demand practically