"For I hold that it is only when we can prove everything we assert that we understand perfectly the thing under consideration."

"He who hasn't tasted bitter things hasn't earned sweet things."

"I am not one of those people whose minds are so limited that they are unable to conceive of more than one kind of substance."

"For the glory of God is the ultimate end of all things."

"It is a bad thing to be a heretic, but it is worse to be a schismatic."