The great trick of regarding small departures from the truth as the truth itself - on which is founded the entire integral calculus - is also the basis of our witty speculations, where the whole thing would often collapse if we considered the departures with philosophical rigour.

God creates the animals, man creates himself.

Many are less fortunate than you' may not be a roof to live under, but it will serve to retire beneath in the event of a shower.

Above all things expand the frontiers of science: without this the rest counts for nothing.

Some people read only because they are too lazy to think.

A man of spirit must not think of the word difficulty as so much as existing. Away with it!

It is a question whether, when we break a murderer on the wheel, we do not fall into the error a child makes when it hits the chair it has bumped into.