In the preface to the Lyrical ballads Wordsworth says that principally the subject matter of his poetry was the life, manners, interests and occupations of the rustics and common men of rural background because they were a part of nature. Consequently, he tried to write his poetry in the language really used by them. So Wordsworth writes in the preface: "The principal object proposed in these poems was to choose incidents and situations from common life, and to relate or describe them as far as possible in a selection of language really used by men." The language of these men had been adopted because such men hourly communicate with the best objects from which the best part of language is originally derived. Such a language, he holds "is a more permanent and a far more philosophical language".
However, as a precautionary measure Wordsworth says that the language of the common men would, of course, be "purified from what appear to be its real defects, from all lasting and rational causes of dislike or disgust". Wordsworth totally rejected the use of "poetic diction". He believes that the best of poems can be written in the normal language of a common man. He says, "Except for the difference of metre, the language of poetry would in no respect differ from that of good prose". On the contrary, "some of the most interesting parts of the best poems will be found to be strictly in the language of prose when prose is well written". A large portion of the language of every good poem can in no respect differ from that of a good prose. So Wordsworth concludes, "it may be safely affirmed that there neither is, nor can be, any essential difference between the language of prose and that of metrical composition."