Tom Paine on lying to onself I've always considered self-delusion to be the most dangerous mental state possible. How can you profitably (or even safely) interact with the world when you are deliberately choosing to see things as they are not? So it was nice to come across this bit from Paine.

The Age Of Reason: "[I]t is necessary to the happiness of man, that he be mentally faithful to himself. Infidelity does not consist in believing, or in disbelieving; it consists in professing to believe what he does not believe.

"It is impossible to calculate the moral mischief, if I may so express it, that mental lying has produced in society. When a man has so far corrupted and prostituted the chastity of his mind, as to subscribe his professional belief to things he does not believe, he has prepared himself for the commission of every other crime."  ¶ 2:45 PM