To begin, poetic diction must be defined. Poetic diction refers to the style of writing used in poetry (the linguistic style, vocabulary, and use of figurative language--normally metaphors). Up until Wordsworth's writing of the 1802 preface to Lyrical Ballads, the adherence to the poetic diction had yet to be seriously challenged.
Wordsworth's issue, essentially, with the use and adherence to poetic diction was the fact that it tended to alienate the common man. Given that the common man did not speak using elevated vocabulary and figurative language, Wordsworth believed, given he wanted poetry to speak to all, that complete adherence to poetic diction needed to be dropped.
Perhaps the best way to illustrate Wordsworth's point on the elimination of poetic diction is to examine the 1802 preface of Lyrical Ballads:
There will also be found in these volumes little of what is usually called poetic diction; I have taken as much pains to avoid it as others ordinarily take to produce it; this I have done for the reason already alleged, to bring my language near to the language of men, and further, because the pleasure which I have proposed to myself to impart is of a kind very different from that which is supposed by many persons to be the proper object of poetry.
The term diction refers to the kinds of words, phrases and sentence structures, and sometimes figurative language that constitute any work of literature. In the theory of poetry, the issue of diction tends to become primary because the feelings of the poet are most readily conceived to overflow into words, unlike into plot or characters. The poets in all ages have used a distinctive language, a “poetic diction” which is not correct in ordinary discourse.
The neo-classical poetic diction was mainly derived from the classical poets such as Virgil, Spenser, Milton and was based on the principal of decorum. Moreover, prominent features of the eighteenth century poetic diction where archaism, preference for resounding words derived from Latin, a personification of inanimate objects and to avoid what were regarded as low, technical or common place terms by means of substitute phrase that was dignity and decorum.
In William Wordsworth’s famed attack on the neo-classical doctrine of a special language for poetry,in his preface to 1800 Lyrical Ballads, he claimed: “There is no difference between language of poetry and language of prose.” He states that the poetic diction of eighteenth century writers as artificial and unnatural.
Wordsworth’s prime concern is not only with the single word or the grammatical order of discourse, but with figurative departures from literary discourse. Wordsworth’s chief aim is to show that such deviations are reasonable in poetry only when they match with the imagery and idea which the poet wishes to universalize and that they have in the speech of everyday life. It is obvious that Wordsworth is contradicting Pope’s theory, who claims, “True wit is nature to advantage dressed and true expression consists in giving thoughts their just and appropriate ‘dress’ and ornament. To Wordsworth all such wit is fake, forced adjustment of words and phrase and rhetorical ornament to them stop ‘genuine’ poetry.
Wordsworth rejects the idea of language as artificial and metres and figures of speech as embellishments of the language. He justifies its use only when they are naturally suggested by passion unlike ‘supposed ornaments.’In a nutshell, so the natural expression of feeling can not be communicated with the help of a version of the upper class speech, but with the actual speech of “humble and rustic life.”
The Neo-classical poets insisted on the perfection of language rather than subject matter. They adopted the method of revising their writing till it is said in the fewest possible as well as the best possible words. The poets avoided writing the words which were coarse, vulgar and unsuitable in their work. Their aim was not only to make language lofty and grandeur but also its style. In result, they introduced artificial poetic diction and style that made the language different from every day and rustic life. William Wordsworth followed very simple language or the language of country side. He used simple and attractive diction coming out spontaneously. His language looked to be natural. He used conceits, images, symbols, metaphors similes, alliterations etc. All added great beauty to the work, and his style became very lofty to all the common people as Longinus has depicted in his work "On the Sublime".His using such language and style is wonderful.