I've had photographs taken for portraits because I very much prefer working from the photographs than from models... I couldn't attempt to do a portrait from photographs of somebody I didn't know.

Such philosophy as shall not vanish in the fume of subtile, sublime, or delectable speculation but shall be operative to the endowment and betterment of man's life.

Velazquez found the perfect balance between the ideal illustration which he was required to produce, and the overwhelming emotion he aroused in the spectator.

Everybody has his own interpretation of a painting he sees.

...those experiments be not only esteemed which have an immediate and present use, but those principally which are of most universal consequence for invention of other experiments, and those which give more light to the invention of causes; for the invention of the mariner's needle, which giveth the direction, is of no less benefit for navigation than the invention of the sails, which give the motion.

If a man will begin with certainties, he shall end in doubts, but if he will content to begin with doubts, he shall end in certainties.

Riches are for spending, and spending for honor and good actions; therefore extraordinary expense must be limited by the worth of the occasion.