By this and this only...

...blood shaking my heart
The awful daring of a moment's surrender
Which an age of prudence can never retract,
By this, and this only, we have existed,
Which is not to be found in our obituaries
Or in memories draped by the beneficent spider
Or under seals broken by the lean solicitor
In our empty rooms.

- Thomas Stearns Eliot (The Wasteland)