Your joy is your sorrow unmasked. And the self-same well from which your laughter rises was often-times filled with your tears.

Good sense is the most equitably distributed of all things because no matter how much or little a person has, everyone feels so abundantly provided with good sense that he feels no desire for more than he already possesses.

The greatest minds are capable of the greatest vices as well as of the greatest virtues.

Archimedes, that he might transport the entire globe ... demanded only a point that was firm and immovable; so also, I shall be entitled to entertain the highest expectations, if I am fortunate enough to discover only one thing that is certain and indubitable.

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

The only secure knowledge is that I exist.

Let whoever can do so deceive me, he will never bring it about that I am nothing, so long as I continue to think I am something.