But because I believe that the reward of discipline is greater than its immediate objective, I would not have you think that discipline is without objective is possible: in its nature discipline involves the subjection of the soul to some perhaps minor end; and that end must be real, if the discipline is not to be factitious. Therefore I think that all things which evoke discipline: study, and our duties to men and to the commonwealth, war, and personal hardship, and even the need for subsistence, ought to be greeted by us with profound gratitude, for only through them can we attain to the least detachment; and only so can we know peace.

J. Robert Oppenheimer, in Richard Rhodes, The Making of the Atomic Bomb