The Book of the science of Mechanics must precede the Book of useful inventions.

Though I may not . . . be able to quote other authors, I shall rely on that which is much greater and more worthy - on experience.

Everything proceeds from everything else and everything becomes everything, and everything can be turned into everything else.

Medicine is the restoration of discordant elements; sickness is the discord of the elements infused into the living body.

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, but not with a corresponding degree of strength, though it is deficient only in the power of maintaining equilibrium. We may therefore say that such an instrument constructed by man is lacking in nothing except the life of the bird, and this life must needs be supplied from that of man.

once you have tasted the taste of sky, you will forever look up

The function of muscle is to pull and not to push, except in the case of the genitals and the tongue.