Background (from Pfau's introduction): Most scholars have heretofore thought Wordsworth's text (his Preface, that is) as "marked by internal tensions, inconsistencies, discontinuous argument, and a confused sense of purpose" (125). This is because most of them are based on Coleridge's original criticism of the Preface, which judges Wordsworth's poetry theory contradictory and the Preface incompatible with the poems in the collection. Essentially, Coleridge thought the Preface confused the audience further.
It's important to understand that Wordsworth seemed fully aware that reality is correlated to how one defines it--not in how one perceives it (126). The difference is that definition of reality depends upon use of language, which is dependent upon one's community (probably because language and ideas are dependent upon one another while perception can be free of both).
Pfau contends that Wordsworth focuses on the centrality (importance) of feeling, figurative language, and the rustic which is part of his (original) romantic cultural and social theory. Here, he advances (perhaps for the first time) an "intrinsically political theory of culture" as "a theory of discourse" (127). He thus argues that discourse, poetry, and culture are fundamentally connected (127).
So...on with section 1:
At the end of the Preface, Wordsworth says that poetic style and cultural theory are interrelated. (Wordsworth's quote on page 127 in this section points out the three things he's combining that are original to him: he uses poetry to deal with common subjects using common language. It is crucial to understand that this is essentially what he's defending in his Preface. Poetry, up to this point, used highly affected language to praise the aristocracy and talk about high-falootin' ideas; Wordsworth brought it down to earth in Lyrical Ballads. Pfau argues that through this collection and in his Preface, Wordsworth thus transforms poetry into a medium for cultural and political commentary and change.)
The point of Part I is to address what Wordsworth means by "general interest" in this quote:
...having thus explained a few of my reasons for writing in verse, and why I have chosen subjects from common life, and endeavoured to bring my language near to the real language of men, if I have been too minute in pleading my cause, I have at the same time been treating a subject of general interest. (qtd. on 127).
When Pfau uses the word "pragmatics," he refers to the cultural applications of Wordsworth's Preface. Wordsworth's Preface intents to construct a "unified theory of value" (128).
When Wordsworth talks about restoring consistency and sincerity to poetry, he also hopes to restore his culture's homogeneity. He insists that "good poetry" must "transcend history" (128). Wordsworth's technique in promoting the authenticity of humans is to approach his subjects--at least in the poetry itself--with humility. When Wordsworth talks about this in his Preface, he limits the application of his humility to poetry (128). As per Wordsworth, a fully-developed theory of poetry would require us to examine the overlap between the writer's ability to understand and translate ideas with how well his intended audience understands them. Pfau asserts that Wordsworth understates the political and metaphysical impact of any discourse, since he professes to focus on poetic diction, which erodes "the poet's spiritual authority and poetry's cultural efficiency" (129).
* Am I the only one who finds unimaginable irony in the fact that scholarly writing about Wordsworth's "common language about common subjects" approach is itself so obtuse as to require a "common language" translation? (When you have time, you may find this article most enlightening and amusing.)
Discourse--how we use language--determines how history itself plays out. Wordsworth recognizes that discourse both influences history and is influenced by social change, and is thus inseparable from it. So: Poetry--famously "the spontaneous overflow of feeling..."--is where the struggle between self-identity and the forces of communication (linked with social change) take place.
Pfau concludes this section with the observation that because "the subject" is important (as Wordsworth asserts), and the depiction of the threat posed by historical contingency is necessarily male (or was at the time), so the figure of poetic redemption is also male. "Authentic poetic speech" is therefore masculine. The poet, therefore, is a man speaking to other men (132).
I think that is about the gist of it.
(Incidentally...I think I'm being reasonably clear in my translation, but that may be because it seems that way in comparison to Pfau's writing.)
Wordsworth is interested not just in "taste" in discourse, but in how it communicates the variation of society itself (including shifts in class and political etc. changes in history) (129). Wordsworth wants to talk about all of these ideas specifically in his poetry. Up to that point, all of these ideas had been discussed (in poetry) in the general overarching sense, but not in specific, concrete language, since poetry was supposed to use "proper poetic" language--that is, language that we would consider deliberately obtuse, as did Wordsworth. In using common language to talk about common people and ideas, Wordsworth hopes his audience will see history and community in a new (political) way. Poetry, to him, is (or should be) a political statement (something we now take for granted). And because language is so linked to the ideas we are able to have, his contemporaries' understanding of history had ravaged "the 'human mind'" itself (130).
Wordsworth thinks that poetry should be aimed at "the primary laws of our nature," but it isn't fair to be critical of his ideas because his Preface is itself so general. Instead, we should examine how he uses the rhetoric of the Preface to provide an example of how one can identify "stylistic and poetic values with social and communal ones" (130). Thus, he uses the "oppressive" aesthetics in contemporary poetry as proof of how his own society was trapped in "a multitude of causes...acting with a combined force to blunt the discriminating powers of the mind...to reduce it to a state of almost savage torpor" (qtd. in Pfau 130). In essence, if Wordsworth could change poetry to be more clear and deal specifically with common, important subjects, he can simultaneously reduce the confusion of his own society regarding the historical change it was in the midst of. The confusion that historical change causes creates confusion of expression. Pfau argues that Wordsworth asserts that the human essence transcends historical time and place (131).