Though it is a prose work, Coleridge's Biographia Literaria is similar to Wordsworth's magnum opus The Prelude, in that both are a kind of transcript of a poet's inner thoughts and feelings. Coleridge's writing can also be seen as a summation of the Romantic age that had thus far transpired—its first two decades, since his and Wordsworth's publication of Lyrical Ballads in 1798.

In this work, Coleridge is concerned with his own personal development, describing his days at school, his formative academic and literary influences, and his mature life as a poet and as a man involved in the contemporary literary scene. The impression one gets from the book as a whole is that Coleridge was a brilliant and an enormously well-read person. He refers to a plethora of authors, philosophers, and cultural figures, many of whom are little known today, but also many who are among the indispensable thinkers in the history of civilization. He extensively quotes Latin and Greek works in the original languages. Though he does not present a systematic literary or philosophical theory of his own, he draws important conclusions about aesthetics, which have become a central part of literary theory and, indirectly, literary practice in the two hundred years since Biographia Literaria was published.

Among those conclusions is the distinction he draws between imagination and fancy. Imagination is, put simply, creative power; fancy, as Coleridge defines it, is

no other than a mode of Memory emancipated from the order of time and space, and blended with, and modified by, that empirical phenomenon of the will which we express by the word CHOICE.

Another major concern of the work is the language appropriate to poetry, and on this point, Coleridge takes issue with his friend Wordsworth. Though he and Wordsworth had collaborated on Lyrical Ballads nearly twenty years earlier, Coleridge does not fully agree with Wordsworth's condemnation of "poetic diction" and his dictum that such special word usages should be excluded from poetry.

This particular section of Biographia Literaria is emblematic of the general thrust of the book and of the underlying purpose Coleridge had in writing it. Poets were, of course, aware that a seismic change in Western culture was occurring during the late eighteenth and early nineteenth century. The Romantic movement in art was a corollary of the political and religious transformation of Europe and America that had begun with the Enlightenment and reached a climax during the upheavals of the French Revolution and the Napoleonic wars.

Biographia Literaria is Coleridge's attempt at employing a kind of picture of his own mind to represent the entire zeitgeist. Even before he has begun his more extensive ruminations on literary and philosophical concepts, he summarizes his poetic ideal through the use of a negative example, regarding his early reaction to the poetry of Pope. Coleridge sees neoclassical poetry as the use of poetic language to deal with non-poetic subjects. We can understand this point in conjunction with Wordsworth's statement that poetry is the expression of powerful feelings. In Coleridge's view of Pope—and in Wordsworth's summary of the opposite, positive ideal—the difference between the classical aesthetic and the Romantic one is made clear. The latter triumphed two hundred years ago and, in many ways, is an ideal which is still pervasive today. The same is true of most of the thoughts expressed in the Biographia. The work is an exuberant outpouring of opinions, deeply held feelings, and personal reactions. It is not only Coleridge's self-portrait but also an attempt to paint a picture of the modern mind, of the collective psyche dominant in Western civilization over the past two centuries.