Clarity of mind means clarity of passion, too.

Love has reasons which reason cannot understand.

And is it not obvious that, just as it is a crime to disturb the peace when truth reigns, it is also a crime to remain at peace when the truth is being destroyed?

When we do not know the truth of a thing, it is good that there should exist a common error which determines the mind of man, as, for example, the moon, to which is attributed the change of seasons, the progress of diseases, etc. For the chief malady of man is a restless curiosity about things which he cannot understand; and it is not so bad for him to be in error as to be curious to no purpose.

Lord, help me to do great things as though they were little, since I do them with your power; And little things as though they were great, since I do them in your name!

All I know is that I must soon die, but what I know least is this very death which I cannot escape.

Man's greatness lies in his power of thought.