The most necessary learning is that which unlearns evil.

The most useful piece of learning for the uses of life is to unlearn what is untrue.

To all my friends without distinction I am ready to display my opulence: come one, come all; and whosoever likes to take a share is welcome to the wealth that lies within my soul.

We must not contradict, but instruct him that contradicts us; for a madman is not cured by another running mad also.

I am sadly afraid that I must have done some wicked thing.

As iron is eaten away by rust, so the envious are consumed by their own passion.

The advantages of philosophy? That I am able to hold converse with myself.