Leonardo da Vinci

I have offended God and mankind because my work did not reach the quality it should have.

A well-spent day brings happy sleep.

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.

Let no man who is not a mathematician read my principles.

The earth without wood is like a man without his beard.

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.

The function of the human body is to serve the mind.

Medicine is the restoration of the soul to the body.

The eye sees a thing more clearly in dreams than the imagination awake.

Time stays, we go.

Nothing can be loved or hated unless it is first known.

The soul cannot think without a picture.

As a well-spent day brings happy sleep, so life well-used brings happy death.

The five senses are the ministers of the soul.

He who does not punish evil commands it to be done.

The truth of things is the chief nutriment of superior intellects.

I wish to work miracles.

The bridge over the river is like the leg of a man.

Machines will make war without men.

The air attracts the clouds, as the magnet attracts iron.