All things will be produced in superior quantity and quality, and with greater ease, when each man works at a single occupation, in accordance with his natural gifts, and at the right moment, without meddling with anything else.

I would fain grow old learning many things.

Life should be lived as play.

Wisest is he who knows what he does not know.

The ludicrous state of solid geometry made me pass over this branch.

That which is apprehended by intelligence and reason is always in the same state; but that which is conceived by opinion with the help of sensation and without reason, is always in a process of becoming and perishing and never really is.

To suffer the penalty of too much haste, which is too little speed.