"How close men, despite all their knowledge, usually live to madness? What is truth but to live for an idea? When all is said and done, everything is based on a postulate; but not until it no longer stands on the outside, not until one lives in it, does it cease to be a postulate. (Dialectic - Dispute)"
January 1, 1970
https://en.wikiquote.org/wiki/S%C3%B8ren_Kierkegaard