He who in reasoning cites authority is making use of his memory rather than of his intellect. — Leonardo da Vinci Copy Share Image
He who does not understand the supreme certainty of mathematics is wallowing in confusion. — Leonardo da Vinci Copy Share Image
Avoid the precepts of those thinkers whose reasoning is not confirmed by experience. — Leonardo da Vinci Copy Share Image
If you find from your own experience that something is a fact and it contradicts what some authority has written down, then… — Leonardo da Vinci Copy Share Image
No human investigation can claim to be scientific if it doesn't pass the test of mathematical proof. — Leonardo da Vinci Copy Share Image
The evil which does me no harm is like the good which in no wise avails me. — Leonardo da Vinci Copy Share Image
A painter should begin every canvas with a wash of black, because all things in nature are dark except where exposed by the light. — Leonardo da Vinci Copy Share Image
An arch consists of two weaknesses which, leaning one against the other, make a strength. — Leonardo da Vinci Copy Share Image
But to me all sciences seem vain and full of error that are not born of experience, mother of all certainty, and do not… — Leonardo da Vinci Copy Share Image
It is ordained that to the ambitious, who derive no satisfaction from the gifts of life and the beauty of the world, life shall… — Leonardo da Vinci Copy Share Image
Be a mirror, absorb everything around you and still remain the same — Leonardo da Vinci Copy Share Image
Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking,… — Leonardo da Vinci Copy Share Image
People reveal themselves completely only when they are thrown out of the customary conditions of their life. — Leonardo da Vinci Copy Share Image
To be a winner you must want to win but must know of the chance of losing and must not fear of it. — Leonardo da Vinci Copy Share Image
Nature is so delightful and abundant in its variations that among trees of the same kind there would not be found one which nearly… — Leonardo da Vinci Copy Share Image
