If a preface was ever necessary, it may very likely be thought so to the following work; the title of which (in the proposals publishd some time since) hath much amused, and raised the expectation of the curious, though not without a mixture of doubt, that its purport could ever be satisfactorily answered. For though beauty is seen and confessed by all, yet, from the many fruitless attempts to account for the cause of its being so, enquiries on this head have almost been given up; and the subject generally thought to be a matter of too high and too delicate a nature to admit of any true or intelligible discussion. Something therefore introductory ought to be said at the presenting a work with a face so entirely new; especially as it will naturally encounter with, and perhaps may overthrow, several long received and thorough establishd opinions: and since controversies may arise how far, and after what manner this subject hath hitherto been considerd and treated, it will also be proper to lay before the reader, what may be gathered concerning it, from the works of the ancient and modern writers and painters.
It is no wonder this subject should have so long been thought inexplicable, since the nature of many parts of it cannot possibly come within the reach of mere men of letters; otherwise those ingenious gentlemen who have lately published treatises upon it (and who have written much more learnedly than can be expected from one who never took up the pen before) would not so soon have been bewilderd in their accounts of it, and obliged so suddenly to turn into the broad, and more beaten path of moral beauty; in order to extricate themselves out of the difficulties they seem to have met with in this: and withal forced for the same reasons to amuse their readers with amazing (but often misapplied) encomiums on deceased painters and their performances; wherein they are continually discoursing of effects instead of developing causes; and after many prettinesses, in very pleasing language, do fairly set you down just where they first took you up; honestly confessing that as to grace, the main point in question, they do not even pretend to know any thing of the matter. And indeed how should they? when it actually requires a practical knowledge of the whole art of painting (sculpture alone not being sufficient) and that too to some degree of eminence, in order to enable any one to pursue the chain of this enquiry through all its parts: which I hope will be made to appear in the following work.