nervous current. Your task is to deepen the new path so that the nervous
current will flow into it instead of the old. Now suppose you make an
exception on some occasion and allow the nervous current to travel over
the old path. This unfortunate exception breaks down the bridge which
you had constructed at _X_ from _A_ to _C_. But this is not the only
result. The nervous current, as it revisits the old path, deepens it
more than it was before, so the next time a similar situation arises,
the current seeks the old path with much greater readiness than before,
and vastly more effort is required to overcome it. Some one has likened
the effect of these exceptions to that produced when one drops a ball
of string that is partially wound. By a single slip, more is undone
than can be accomplished in a dozen windings.

The fourth maxim is, _seize every opportunity to act upon your
resolution_. The reason for this will be understood better if you keep
in mind the fact, stated before, that nervous currents once started,
whether from a sense-organ or from a brain-center, always tend to seek
egress in movement. These outgoing nervous currents leave an imprint
upon the modifiable nerve tissues as inevitably as do incoming
impressions. Therefore, if you wish your resolves to be firmly fixed,
you should act upon them speedily and often. "It is not in the moment
of their forming, but in the moment of their producing _motor effects_,
that resolves and aspirations communicate the new 'set' to the brain."
"No matter how full a reservoir of _maxims_ one may possess, and no
matter how good one's _sentiments_ may be, if one has not taken
advantage of every concrete opportunity to _act_, one's character may
remain entirely unaffected for the better." Particularly at time of
emotional excitement one makes resolves that are very good, and a glow
of fine feeling is present. Beware that these resolves do not evaporate
in mere feeling. They should be crystallized in some form of action as
soon as possible. "Let the expression be the least thing in the
world--speaking genially to one's grandmother, or giving up one's seat
in a ... car, if nothing more heroic offers--but let it not fail to take
place." Strictly speaking you have not really completed a resolve until
you have acted upon it. You may determine to go without lunch, but you
have not consummated that resolve until you have permitted it to
express itself by carrying you past the door of the