The-Conquest-of-Happiness-by-Bertrand-Russell

his thoughts and hopes upon something
transcending self can find a certain peace in the
ordinary troubles of life which is impossible to the
pure egoist.
What might be called hygiene of the nerves has
been much too little studied. Industrial psychology,
it is true, has made elaborate investigations into
fatigue, and has proved by careful statistics that if
you go on doing something for a sufficiently long
time you will ultimately get rather tired - a result
which might have been guessed without so much
parade of science. The study of fatigue by
psychologists is mainly concerned with muscular
fatigue, although there are also a certain number of
studies of fatigue in school-children. None of
these, however, touch upon the important problem.
The important kind of fatigue is always emotional
in modern life; purely intellectual fatigue, like
purely muscular fatigue, produces its own remedy
in sleep. Any person who has a great deal of
intellectual work, devoid of emotion, to do - say,