idea, which gives merely a vague, general outline, devoid of details;
and the details are just the real part of it. We can be only
indirectly affected by an abstract idea, and yet it is the abstract
idea alone which will do as much as it promises; and it is the
function of education to teach us to put our trust in it. Of course
the abstract idea must be occasionally explained--paraphrased, as it
were--by the aid of pictures; but discreetly, _cum grano salis_.

SECTION 19. The preceding rule may be taken as a special case of the
more general maxim, that a man should never let himself be mastered
by the impressions of the moment, or indeed by outward appearances at
all, which are incomparably more powerful in their effects than the
mere play of thought or a train of ideas; not because these momentary
impressions are rich in virtue of the data they supply,--it is often
just the contrary,--but because they are something palpable to the
senses and direct in their working; they forcibly invade our mind,
disturbing our repose and shattering our resolutions.

It is easy to understand that the thing which lies before our very
eyes will produce the whole of its effect at once, but that time and
leisure are necessary for the working of thought and the appreciation
of argument, as it is impossible to think of everything at one and the
same moment. This is why we are so allured by pleasure, in spite of
all our determination to resist it; or so much annoyed by a criticism,
even though we know that its author it totally incompetent to
judge; or so irritated by an insult, though it comes from some very
contemptible quarter. In the same way, to mention no other instances,
ten reasons for thinking that there is no danger may be outweighed by
one mistaken notion that it is actually at hand. All this shows the
radical unreason of human nature. Women frequently succumb altogether
to this predominating influence of present impressions, and there are
few men so overweighted with reason as to escape suffering from a
similar cause.

If it is impossible to resist the effects of some external influence
by the mere play of thought, the best thing to do is to neutralize it
by some contrary influence; for example, the effect of an insult may
be overcome by seeking the society of those who have a good opinion of
us; and the unpleasant sensation of imminent danger may be avoided by
fixing our attention on the means of warding it off.

Leibnitz[1]