Simplicity is the ultimate sophistication.

Learning never exhausts the mind.

Tears come from the heart and not from the brain.

I love those who can smile in trouble, who can gather strength from distress, and grow brave by reflection. 'Tis the business of little minds to shrink, but they whose heart is firm, and whose conscience approves their conduct, will pursue their principles unto death.

Where the spirit does not work with the hand, there is no art.

Nothing strengthens authority so much as silence.

Why does the eye see a thing more clearly in dreams than the imagination when awake?

Water is the driving force of all nature.

It had long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things.

The greatest deception men suffer is from their own opinions.

Blinding ignorance does mislead us. Oh! Wretched mortals, open your eyes!

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

I have found that, in the composition of the human body as compared with the bodies of animals, the organs of sense are duller and coarser. Thus, it is composed of less ingenious instruments, and of spaces less capacious for receiving the faculties of sense.

Painting is concerned with all the 10 attributes of sight; which are: Darkness, Light, Solidity and Colour, Form and Position, Distance and Propinquity, Motion and Rest.

Beyond a doubt truth bears the same relation to falsehood as light to darkness.

Experience never errs; it is only your judgments that err by promising themselves effects such as are not caused by your experiments.

It had long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things.

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

Men of lofty genius when they are doing the least work are most active.

Knowledge of the past and of the places of the earth is the ornament and food of the mind of man.

How by means of a certain machine many people may stay some time under water. How and why I do not describe my method of remaining under water, or how long I can stay without eating; and I do not publish nor divulge these by reason of the evil nature of men who would use them as means of destruction at the bottom of the sea, by sending ships to the bottom, and sinking them together with the men in them. And although I will impart others, there is no danger in them; because the mouth of the tube, by which you breathe, is above the water supported on bags of corks.

Leonardo da Vinci discussing his concerns over the impact of his inventions