We pay too little regard to surfaces and too much to depths.
Error is boundless.
Nor hope nor doubt,
Though both be groundless,
Will average out.
Every contemporary freethinker would believe in Christianity if born in medieval England, and slavery if born in ancient Rome.
Those who believe that what you cannot quantify does not exist also believe that what you can quantify, does.
When someone says that an argument has been discredited he means only that it has gone out of style.