Everyone who observes himself doubting observes a truth, and about that which he observes he is certain; therefore he is certain about a truth. Everyone therefore who doubts whether truth exists has in himself a truth on which not to doubt.... Hence one who can doubt at all ought not to doubt the existence of truth.
The majority of mankind is lazyminded, incurious, absorbed in vanities, and tepid in emotion, and is therefore incapable of either much doubt or much faith.
Don't imagine that you'll discover {the truth} by accumulating more knowledge. Knowledge creates doubt, and doubt makes you ravenous for more knowledge. You can't get full eating this way.
We cannot know what faith is if we have never had it, and we cannot obtain it as long as we deny it. Faith and doubt cannot exist in the same mind at the same time, for one will dispel the other.
The materialist is sure that history has been simply and solely a chain of causation, just as the [lunatic] is quite sure that he is simply and solely a chicken. Materialists and madmen never have doubts.
This was charming, no doubt; but they shortly found out That the Captain they trusted so well Had only one notion for crossing the ocean, And that was to tingle his bell.