Alexander Pope's Essay on Criticism (1711) is one of the most important statements about literature in the Augustan Age, also characterized by the term Neoclassicism because its supporters, including Pope, advocated a return to the type of literature created during the Greek classical period.
One of Pope's major arguments in the Essay is that writers, especially poets, should follow Nature, by which he meant the guiding principle of the universe--the highly-ordered, rational, reasonable mind of God:
First follow NATURE, and your Judgment frame/By her just STANDARD, which is still the same:/Unerring Nature,still divinely bright,/One clear, unchang'd and Universal Light. . . . (ll. 69-71)
Pope's goal in these and the following lines is to convince writers that if they follow Nature's unchanging guidelines their writing will always remain true to the guiding principles of the universe, which readers will understand because they, too, desire universal truth.
Following Nature, according to Pope, is the only way for writers to achieve the ultimate goal of good writing:
Life, Force, and Beauty, must to all impart,/At once the SOURCE, and END, and TEST of ART. (ll. 72-73)
Here, Pope makes explicit that the proper goal of any art--and here he would include both literature and visual arts--is to reflect the beauty and truth of Nature and Nature's God rather than to create art that deviates in any degree from Nature's "Standard." Pope is taking a very conservative stance here because he is essentially arguing that there is only one kind of acceptable art--that which reflects Nature--and any art that fails to accomplish these goals is not worth producing.
In lines 74-83, Pope furthers his initial argument by pointing out that proper art achieves its goals "without Show, and without Pomp," that is, by reflecting Nature and truth, art doesn't draw attention to itself as art. And he argues further that those writers who are especially gifted with wit ("to whom Heav'n in Wit has been profuse") are tempted to exercise their wit, which, in Pope's view, is artificial and therefore not a proper component of art:
For Wit and Judgment often are at strife . . . 'Tis more to guide than spur the Muse's Steed. . . . (ll. 82-84)
In other words, poets who are gifted with wit often use that wit rather than appropriate judgment, and the two attributes are often incompatible during the creative process. Instead, according to Pope, wit should be used sparingly and always be tempered by good judgment (and good judgment is guided by Nature).
The poet's goal, as Pope argues in the last four lines of this section, is to tame his wit because his writing is most true to nature when "you check his Course." In other words, wit has a role in the creative process but must be subject to Nature's principles and the poet's judgment.
In essence, one of the principal goals of writers in the Augustan Age or Neoclassical Period (the early 18thC to about mid century) is to model literature and art on the principals of Nature and what they often referred to as "Nature's God," and, equally important, to exercise moderation in all things, especially literature and the visual arts. The "Test of Art" is, then, how closely art reflects Nature.