Instead I ought to be grateful to Him who never owed me anything for having been so generous to me, rather than think that He deprived me of those things or has taken away from me whatever He did not give me.

Divide each difficulty at hand into as many pieces as possible and as could be required to better solve them.

If I found any new truths in the sciences, I can say that they follow from, or depend on, five or six principal problems which I succeeded in solving and which I regard as so many battles where the fortunes of war were on my side.

Be that as it may, there is fixed in my mind a certain opinion of long standing, namely that there exists a God who is able to do anything and by whom I, such as I am, have been created. How do I know that he did not bring it about that there is no earth at all, no heavens, no extended thing, no shape, no size, no place, and yet bringing it about that all these things appear to me to exist precisely as they do now?

... moral certainty is certainty which is sufficient to regulate our behaviour, or which measures up to the certainty we have on matters relating to the conduct of life which we never normally doubt, though we know that it is possible, absolutely speaking, that they may be false.

Even if I were to suppose that I was dreaming and whatever I saw or imagined was false, yet I could not deny that ideas were truly in my mind.

Few look for truth; many prowl about for a reputation of profundity by arrogantly challenging whichever arguments are the best.