ty, till at last there is a serious danger of putting
an end to it altogether.

I know two men, about fifty-five years old both of them, and both of
them admirably active. They tell me that their bodily activity has been
preserved by an effort of the will; that if they had not resolutely kept
up the habit of using legs and arms in daily work or amusement their
limbs would have stiffened into uselessness, and their constitutions
would have been unable to bear the call of any sudden emergency. One of
them has four residences in different parts of the same county, and yet
he will not keep a carriage, but is a pedestrian terrible to his
friends; the other is at the head of a great business, and gives an
example of physical activity to his workpeople. Both have an absolute
faith in habitual exercise; and both affirm that if the habit were once
broken they could never afterwards resume it.

We need this faith in exercise--this firm conviction of its
necessity--the sort of conviction that makes a man go out in all
weathers, and leave the most urgent intellectual labor for the mere
discipline and hardening of the body. Few students possess this faith in
its purity. It is hard to believe that we shall get any good from
exercise proportionate to the sacrifice of time.

The incompatibility between the physical and the intellectual lives is
often very marked if you look at small spaces of time only; but if you
consider broader spaces, such as a lifetime, then the incompatibility is
not so marked, and gives place to a manifest conciliation. The brain is
clearer in vigorous health than it can be in the gloom and misery of
sickness; and although health may last for a while without renewal from
exercise, so that if you are working under pressure for a month the time
given to exercise is so much deducted from the result, it is not so for
the life's performance. Health sustained for many years is so useful to
the realization of all considerable intellectual undertakings, that the
sacrifice to the bodily well-being is the best of all possible
investments.

Franklin's theory about concentrating his exercise for the economy of
time was founded upon a mistake. Violent exertion for minutes is _not_
equivalent to moderate exercise for hours. The desire to concentrate
good of various kinds into the smallest possible space is one of the
commonest of _human_ wishes, but it is not encouraged by the broader
economy of nature. In the exercise of