that it is not being used up to its maximum capacity. Change in these
conditions, then, will enable a person to make use of all the native
retentiveness his nervous system has. One of the most important of these
conditions is good health. To the extent that good blood, sleep,
exercise, etc., put the nervous system in better tone, to that extent
the retentive power present is put in better working order. Every one
knows how lack of sleep and illness is often accompanied by loss in
memory. Repetition, attention, interest, vividness of impression, all
appeal primarily to this so-called "brute memory," or retentive power.
Pleasurable results seem not to be quite so important, and repetition to
be more so when the connections are between mental states instead of
between mental states and motor responses. An emphasis on, or an
improvement in, the use of any one of these factors may call into play
to a greater extent than before the native retentive power of a given
child.

The power to recall a fact or an event depends not only upon this
quality of retentiveness, but also upon the number of other facts or
events connected with it. Each one of these connections serves as an
avenue of approach, a clew by means of which the recall may operate. Any
single blockade therefore may not hinder the recall, provided there are
many associates. This is true, no matter how strong the retentive power
may be. It is doubly important if the retentive power is weak. Suppose a
given fact to be held rather weakly because of comparatively poor
retentive power, then the operation of one chain of associates may not
be energetic enough to recall it. But if this same fact may be
approached from several different angles by means of several chains of
associations, the combined power of the activity in the several neurone
chains will likely be enough to lift it above the threshold of recall.
Other things being equal, the likelihood that a needed fact will be