“If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty.”

“Questioning anything within doubt, will just bring mind to no certainty.”

“You used to give yourself over to endless sessions of doubt. You would claim to be an expert on the subject. But doubting would tire you so much that you would end up doubting doubt itself. I saw you one day at the end of an afternoon of solitary speculation. You were unmoving and petrified. Running several kilometers in a deep forest full of ravines and pitfalls would have exhausted you less.”

“If a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts, he shall end in certainties.”

“We must doubt the certainty of everything which passes through the senses, but how much more ought we to doubt things contrary to the senses, such as the existence of God and the soul.”

“The opposite of faith is not doubt, it’s certainty.”