Chesterton

All the fundamental functions of a healthy man ought emphatically
to be performed with pleasure and for pleasure; they emphatically
ought not to be performed with precaution or for precaution.
A man ought to eat because he has a good appetite to satisfy,
and emphatically not because he has a body to sustain. A man ought
to take exercise not because he is too fat, but because he loves foils
or horses or high mountains, and loves them for their own sake.
And a man ought to marry because he has fallen in love,
and emphatically not because the world requires to be populated.
The food will really renovate his tissues as long as he is not thinking
about his tissues. The exercise will really get him into training
so long as he is thinking about something else. And the marriage will
really stand some chance of producing a generous-blooded generation
if it had its origin in its own natural and generous excitement.

Chesterton