Among all the beautiful and delightful arts, that of painting has always found the most lovers; the number of them almost including all mankind. Of whom great multitudes are daily found, who value themselves on the knowledge of it: either because they keep company with painters, or that they have seen good pieces; or, lastly, because their gusto is naturally good. Which notwithstanding, that knowledge of theirs (if we may so call it) is so very superficial, and so ill grounded, that it is impossible for them to describe in what consists the beauty of those works, which they admire; or the faults, which are in the greatest part of those which they condemn. And truly it is not hard to find, that this proceeds from no other cause, than that they are not furnished with rules by which to judge; nor have any solid foundations, which are as so many lights set up to clear their understanding, and lead them to an entire and certain knowledge. I think it superfluous to prove, that this is necessary to the knowledge of painting. It is sufficient, that painting be acknowledged for an art; for that being granted, it follows, without dispute, that no arts are without their precepts. I shall satisfy myself with telling you, that this little treatise will furnish you with infallible rules of judging truly; since they are not only founded upon right reason, but upon the best pieces of the best masters, which our author hath carefully examined, during the space of more than thirty years; and on which he has made all the reflections which are necessary, to render this treatise worthy of posterity; which, though little in bulk, yet contains most judicious remarks; and suffers nothing to escape, that is essential to the subject which it handles. If you will please to read it with attention, you will find it capable of giving the most nice and delicate sort of knowledge, not only to the lovers, but even to the professors of that art.