a saying said two thousand years ago cannot be practical.

You remark sagely to your child: 'No, my child, you cannot have that
moon, and you will accomplish nothing by crying for it. Now, here is
this beautiful box of bricks, by means of which you may amuse yourself
while learning many wonderful matters and improving your mind. You must
try to be content with what you have, and to make the best of it. If you
had the moon you wouldn't be any happier.' Then you lie awake half the
night repining because the last post has brought a letter to the effect
that 'the Board cannot entertain your application for,' etc. You say the
two cases are not alike. They are not. Your child has never heard of
Epictetus. On the other hand, justice _is_ the moon. At your age you
surely know that. 'But the Directors _ought_ to have granted my
application,' you insist. Exactly! I agree. But we are not in a universe
of _oughts_. You have a special apparatus within you for dealing with a
universe where _oughts_ are flagrantly disregarded. And you are not
using it. You are lying awake, keeping your wife awake, injuring your
health, injuring hers, losing your dignity and your cheerfulness. Why?
Because you think that these antics and performances will influence the
Board? Because you think that they will put you into a better condition
for dealing with your environment to-morrow? Not a bit. Simply because
the machine is at fault.

In certain cases we do make use of our machines (as well as their sad
condition of neglect will allow), but in other cases we behave in an
extraordinarily irrational manner. Thus if we sally out and get caught
in a heavy shower we do not, unless very far gone in foolishness, sit
down and curse the weather. We put up our umbrella, if we have one, and
if not we hurry home. We may grumble, but it is not serious grumbling;
we accept the shower as a fact of the universe, and control ourselves.