Avoid the precepts of those thinkers whose reasoning is not confirmed by experience.
All our knowledge originates in opinion.
I shall do down in history as the man who opened a door!
The painter who draws by practise and judgment of the eye without the use of reason is like the mirror which reproduces within itself all the objects which are set opposite to it without knowledge of the same.
Love, Fear, and Esteem, - Write these on three stones.
Those who become enamoured of the art, without having previously applied to the diligent study of the scientific part of it, may be compared to mariners who put to the sea in a ship without rudder or compass and therefore cannot be certain of arriving at the wished for port.