Rules are very important for Pope, as they were for neoclassicists in general. In An Essay on Criticism he is anxious to argue quite strongly that following the appropriate rules is conducive to good writing. The target audience of the Essay was very small, consisting of a tiny, well-bred readership drawn largely from the upper classes. If one wished to communicate something of lasting significance to this self-selecting literary elite, then it was thought necessary to speak to them in a language they could understand. There was no place in the world of the eighteenth-century English salon or literary coterie for anything that smacked of eccentricity or overt individuality; to ignore this basic prohibition was considered incredibly rude and ill-mannered.
In part 1 of the Essay, Pope further stresses the importance of following human nature not just in writing, but in any kind of creative endeavor. In common with most people at the time, Pope tended to look upon human nature as fixed. Accordingly, writers must endeavor to express human nature in all its universality. Among other things, this approach would ensure that creative works such as poems and novels would endure long after they were written. As they were concerned with the universal and the general, rather than the particular and the specific, they were able to speak clearly to each successive generation.
If writers wish to convey universal truths in their work, they could do a lot worse, says Pope, than to follow the shining example set by their great forebearers of antiquity such as Cicero, Quintilian, and "The Stagirite," namely, Aristotle. These men have spoken to successive generations, and continue to do so, precisely because they dealt so skillfully with human nature. Therein lies their contemporary relevance.
As a highly skilled poet himself, Pope understands that the poetic temperament often instinctively rebels against specific rules and the formal constraint they impose. This, he feels, is a mistake. The great poets of the past understood the necessity of buckling under the rules bequeathed to them by their predecessors. Indeed, if they had not, then Pope would not be in a position to enjoin the current generation of writers to follow their example.