Leonardo da Vinci

The architect must be a good arithmetician, geometrician, and know how to draw.

The 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 in nothing else.

The movement of the air against the wing, and the wing against the air, is the cause of the bird's flight.

The power of the wind is such that it can carry a ship across the sea.

The force of the water is such that it can turn a mill.

The machine is a means to an end.

The more complex the machine, the more perfect it is.

The engineer must be a man of universal knowledge.

The study of engineering is the study of nature.

The true engineer is one who understands the laws of nature.

Once you have tasted flight, you will forever walk the earth with your eyes turned skyward.

Nature is the source of all true knowledge. She has her own logic, her own laws.

I have been impressed with the urgency of doing. Knowing is not enough; we must apply. Being willing is not enough; we must do.

The knowledge of past errors binds us to the future.

He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast.

The painter who draws by formula will never give his work the life and vitality that it requires.

In the sciences, the authority of thousands of books is not worth as much as one tiny spark of genius in an ignorant man.

Our body is dependent on heaven and earth, and although it resembles them, it is incomparably more perfect.

Obstacles cannot crush me. Every obstacle yields to stern resolve.

While I thought that I was learning how to live, I have been learning how to die.