One painter ought never to imitate the manner of any other; because in that case he cannot be called the child of nature, but the grandchild. It is always best to have recourse to nature, which is replete with such abundance of objects, than to the productions of other masters, who learnt everything from her.
Leonardo da VinciPerspective 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.
Leonardo da VinciWe must doubt the certainty of everything which passes through the senses, but how much more ought we to doubt things contrary to the senses, such as the existence of God and the soul.
Leonardo da VinciI have from an early age abjured the use of meat, and the time will come when men such as I will look upon the murder of animals as they now look upon the murder of men.
Leonardo da Vinci