Another reason why limitation makes for happiness is that the second
half of life proves even more dreary that the first. As the years wear
on, the horizon of our aims and our points of contact with the world
become more extended. In childhood our horizon is limited to
the narrowest sphere about us; in youth there is already a very
considerable widening of our view; in manhood it comprises the whole
range of our activity, often stretching out over a very distant
sphere,--the care, for instance, of a State or a nation; in old age it
embraces posterity.

But even in the affairs of the intellect, limitation is necessary if
we are to be happy. For the less the will is excited, the less we
suffer. We have seen that suffering is something positive, and that
happiness is only a negative condition. To limit the sphere of outward
activity is to relieve the will of external stimulus: to limit the
sphere of our intellectual efforts is to relieve the will of internal
sources of excitement. This latter kind of limitation is attended by
the disadvantage that it opens the door to boredom, which is a direct
source of countless sufferings; for to banish boredom, a man will
have recourse to any means that may be handy--dissipation, society,
extravagance, gaming, and drinking, and the like, which in their turn
bring mischief, ruin and misery in their train. _Difficiles in otio
quies_--it is difficult to keep quiet if you have nothing to do. That
limitation in the sphere of outward activity is conducive, nay, even
necessary to human happiness, such as it is, may be seen in the fact
that the only kind of poetry which depicts men in a happy state of
life--Idyllic poetry, I mean,--always aims, as an intrinsic part of
its treatment, at representing them in very simple and restricted
circumstances. It is this feeling, too, which is at the bottom of the
pleasure we take in what are called _genre_ pictures.