A learned man is not learned in all things; but a sufficient man is sufficient throughout, even to ignorance itself.
And obstinacy is the sister of constancy, at least in vigour and stability.
The most certain sign of wisdom is cheerfulness.
Speech belongs half to the speaker, half to the listener. The latter must prepare to receive it according to the motion it takes.
What fear has once made me will, I am bound still to will when without fear.
This notion [skepticism] is more clearly understood by asking "What do I know?"