will lead to others similar to those we have already mentioned.

"We have merely sketched rapidly the scale of sensations which follow
each other, in order to reach the explanation of how foresight is formed,
this faculty of which we are now speaking.

"By assimilating these present facts with those of the past, we are
permitted to draw a conclusion, relating to the same group of results,
because of the conformity of those past facts to the present questions.

"Foresight is passive; between it and precaution there is the same
difference as between theory and practise.

"Precaution is preeminently active, and it marks its first appearance by
means of foresight, but does not stop in this effort until it has
rendered foresight productive.

"It is well to foresee, but it is precious to preclude.

"The second part of the act of precaution can, however, only be
accomplished after having permitted the brain to register the thoughts
which determine the first part of this act."

In order to understand this very subtle difference, but very important
one, which classifies these two sentiments, the old sage gives us the
following example:

"Let us suppose," he says, "that, on a beautiful day in spring, a man
starts out for an excursion which will last until the dawn of the
following day.