The principal and most important part of painting is, to know what is most beautiful in nature, and most proper for that art. That which is the most beautiful is the most noble subject: so in poetry, tragedy is more beautiful than comedy; because, as I said, the persons are greater whom the poet instructs, and consequently the instructions of more benefit to mankind: the action is likewise greater and more noble, and thence is derived the greater and more noble pleasure. To imitate nature well in whatsoever subject, is the perfection of both arts; and that picture, and that poem, which comes nearest to the resemblance of nature, is the best. But it follows not, that what pleases most in either kind is therefore good, but what ought to please. Our depraved appetites, and ignorance of the arts, mislead our judgments, and cause us often to take that for true imitation of nature, which has no resemblance of nature in it. To inform our judgments, and to reform our tastes, rules were invented, that by them we might discern—when nature was imitated, and how nearly. I have been forced to recapitulate these things, because mankind is not more liable to deceit, than it is willing to continue in a pleasing error, strengthened by a long habitude. The imitation of nature is therefore justly constituted as the general, and indeed the only, rule of pleasing, both in poetry and painting. Aristotle tells us, that imitation pleases, because it affords matter for a reasoner to inquire into the truth or falsehood of imitation,[125] by comparing its likeness, or unlikeness, with the original; but by this rule, every speculation in nature, whose truth falls under the inquiry of a philosopher, must produce the same delight, which is not true. I should rather assign another reason. Truth is the object of our understanding, as good is of our will; and the understanding can no more be delighted with a lie, than the will can choose an apparent evil. As truth is the end of all our speculations, so the discovery of it is the pleasure of them; and since a true knowledge of nature gives us pleasure, a lively imitation of it, either in poetry or painting, must of necessity produce a much greater: for both these arts, as I said before, are not only true imitations of nature, but of the best nature, of that which is wrought up to a nobler pitch. They present us with images more perfect than the life in any individual; and we have the pleasure to see all the scattered beauties of nature united by a happy chemistry, without its deformities or faults. They are imitations of the passions, which always move, and therefore consequently please; for without motion there can be no delight, which cannot be considered but as an active passion. When we view these elevated ideas of nature, the result of that view is admiration, which is always the cause of pleasure.