Supreme happiness will be the greatest cause of misery, and the perfection of wisdom the occassion of folly.

I roamed the countryside searching for the answers to things I did not understand. Why shells existed on the tops of mountains along with the imprints of coral and plant and seaweed usually found in the sea. Why the thunder lasts a longer time than that which causes it and why immediately on its creation the lightening becomes visible to the eye while thunder requires time to travel. How the various circles of water form around the spot which has been struck by a stone and why a bird sustains itself in the air. These questions and other strange phenomena engaged my thought throughout my life.

The greatest geniuses sometimes accomplish more when they work less.

Putting your hand into a river, you simultaneously touch the last of what is passing and the first of what is coming.

Those who are enamoured of practice without science are like a pilot who goes into a ship without rudder or compass and never has any certainty of where he is going. Practice should always be based upon a sound knowledge of theory.

I have discovered that a screw-shaped device such as this, if it is well made from starched linen, will rise in the air if turned quickly.

Perspective is nothing more than a rational demonstration applied to the consideration of how objects in front of the eye transmit their image to it, by means of a pyramid of lines. The Pyramid is the name I apply to the lines which, starting from the surface and edges of each object, converge from a distance and meet in a single point.