When you have eliminated all other possible explanations, the one that remains, however unlikely, must be that you missed something.
Erring
Error is boundless.
Nor hope nor doubt,
Though both be groundless,
Will average out.
—Cunningham
The heretic is not punished for error: he is punished for heresy.
Few would deny that the earth was flat if it were a small inconvenience to maintain that it is round.
Belief is an equilibrium, and that is just the trouble.
We invent metrics partly to dignify arguments, but mostly to disguise them.
Untried beliefs are the most firmly held.
There are entire fields, like psychiatry and philosophy, devoted chiefly to exploding the errors that they create.
A man should be pleased to make subtle errors; it means he has avoided the obvious ones.
The inability to fathom a design without a designer leads to hostility to markets in half of the world, and hostility to Darwin in the other half.
To make a grave error clearly and follow it through consistently will place a man among the greatest of philosophers.