Our life is made by the death of others.

I have from an early age abjured the use of meat, and the time will come when men such as I will look upon the murder of animals as they now look upon the murder of men.

The human being, creature of eyes, needs the image.

Men wrongly lament the flight of time, blaming it for being too swift; they do not perceive that its passage is sufficiently long, but a good memory, which nature has given to us, causes things long past to seem present.

I shall do down in history as the man who opened a door!

A bird is an instrument working according to mathematical law, which instrument it is within the capacity of man to reproduce with all its movements.

He who walks straight rarely falls.