One cannot conceive anything so strange and so implausible that it has not already been said by one philosopher or another.

I think; therefore I am.

Illusory joy is often worth more than genuine sorrow.

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

Common sense is the most fairly distributed thing in the world, for each one thinks he is so well-endowed with it that even those who are hardest to satisfy in all other matters are not in the habit of desiring more of it than they already have.

The reading of all good books is like a conversation with the finest minds of past centuries.