Leonardo da Vinci
"Seeing that I can find no subject specially useful or pleasing - since the men who have come before me have taken for their own every useful or necessary theme - I must do like one who, being poor, comes last to the fair, and can find no other way of providing himself than by taking all the things already seen by other buyers, and not taken but refused by reason of their lesser value. I, then, will load my humble pack with this despised and rejected merchandise, the refuse of so many buyers, and will go about to distribute it, not indeed in great cities, but in the poorer towns, taking such a price as the wares I offer may be worth."

"I know that many will call this useless work, and they will be those of whom Demetrius declared that he took no more account of the wind that came out of their mouth in words, than of that that they expelled from their lower parts: men who desire nothing but material riches and are absolutely devoid of that of wisdom, which is the food and the only true riches of the mind. For so much more worthy is the soul than the body. And often, when I see one of these men take this work in his hand, I wonder that he does not put it to his nose, like a monkey, or asking me if it is something good to eat."