Ik denk dat je eigenlijk moet lezen:

True wit is nature to advantage dressed,
[true with is] what oft was thought, but ne'er so well expressed,

De volgende tekst legt uit het je het citaat moet intertpreteren:

The excerpt taken from Pope's essay on criticism presents a highly academic conception of wit and its proper function in literature. Simply and clearly stated, Pope's wit is that which immediately captures the exact essence of a subject more precisely and cleverly than any have before. His very definition captures, in its directness of expression, the nature of the subject described. In combination with the even rhythm and masculine rhyme of the neoclassical couplets, the preference for perfect clarity of statement reflects the rational bent instigated to a large degree by such major and recent scientific advances as those represented by Newton's Principia (published 1687) and the invention of the microscope. Furthermore, the demystification of the natural world which lead to the spread of Deism can also be seen to contribute to Pope's explanation of that wit which he strives for as a poet. This factor is especially significant when one considers that he himself was a Deist, and partook of the belief that the relationship of man to God can be understood through reason.