Full Idea
Let man consider what he is in comparison with what exists; let him regard himself as lost, and from this little dungeon the universe, let him learn to take the earth and himself at their proper value. Anyone considering this will be terrified at himself.
Gist of Idea
If man considers himself as lost and imprisoned in the universe, he will be terrified
Source
Blaise Pascal (Pensées [1662], p.199), quoted by Kevin Aho - Existentialism: an introduction Pref 'What?
Book Reference
Aho,Kevin: 'Existentialism: an introduction' [Polity 2014], p.-9
A Reaction
[p.199 of Penguin edn] Cited by Aho as a forerunner of existentialism. Montaigne probably influenced Pascal. Interesting that this is to be a self-inflicted existential crisis (for some purpose, probably Christian).