This laborious investigation, I am aware, must appear superfluous to those who think everything is to be done by felicity and the powers of native genius. Even the great Bacon treats with ridicule the idea of confining proportion to rules, or of producing beauty by selection. "A man cannot tell," says he, "whether Apelles or Albert Durer were the more trifler: whereof the one would make a personage by geometrical proportions; the other, by taking the best parts out of divers faces, to make one excellent. . . The painter," he adds, "must do it by a kind of felicity . . . and not by rule."[2] It is not safe to question any opinion of so great a writer, and so profound a thinker, as undoubtedly Bacon was. But he studies brevity to excess; and therefore his meaning is sometimes doubtful. If he means that beauty has nothing to do with rule, he is mistaken. There is a rule, obtained out of general Nature, to contradict which is to fall into deformity. Whenever anything is done beyond this rule, it is in virtue of some other rule which is followed along with it, but which does not contradict it. Everything which is wrought with certainty, it is wrought upon some principle. If is not, it cannot be repeated. If by felicity is meant anything of chance or hazard, or something born with a man, and not earned, I cannot agree with this great philosopher. Every object which pleases must give us pleasure upon some certain principles: but as the objects of pleasure are almost infinite, so their principles vary without end, and every man finds them out, not by felicity or successful hazard, but by care and sagacity. To the principle I have laid down, that the idea of beauty in each species of beings is an invariable one, it may be objected, that in every particular species there are various central forms, which are separate and distinct from each other, and yet are undeniably beautiful; that in the human figure, for instance, the beauty of Hercules is one, of the Gladiator another, of the Apollo another; which makes so many different ideas of beauty.