The earliest major work of literary criticism, in the west at least, is "Poetics" by the philosopher Aristotle, dating from the fourth century B.C. Poetry was not sharply distinguished from performance art in ancient times and the main subject of Aristotle's work is the art of tragedy, although he does examine distinctive characteristics of poetic language, such as rhythm, harmony and meter. Aristotle's influence dominated literary criticism for centuries.
Criticism emerged as a professional calling the eighteenth century. The English author Dr. Samuel Johnson used his extensive biographical survey, "Lives of of the Most Eminent English Poets" (1779--81), as an opportunity to assess the work of the poets discussed. Johnson's contemporary, Alexander Pope, was the author of a savagely critical epic, "The Dunciad," which mercilessly ridiculed his poetic contemporaries. The Romantic movement in England and Germany produced a number of major critics in the early nineteenth century; the poet Coleridge attempted to develop principles of poetic criticism in "Biographia Literaria." By the end of the century, literary criticism was established as an academic discipline through figures like Matthew Arnold, a poet who became Oxford Professor of Poetry in 1857.
The modern period is characterized by questions about critical method. T.S. Eliot emphasized tradition over individual talent, proposing that poets "...must inevitably be judged by the standards of the past." The critical school which dominated the reading of poetry in the United States and England in the mid-twentieth century, the New Criticism, rejected the study of historical and biographical contexts, and insisted readers focus on the self-contained text of the poem. Poetry, for the New Critics,was not about the poet's feelings and experiences, but about the words on the page and their metaphorical and symbolic functions. William Wimsatt called the belief that the poet's personal intentions were basic to the meaning of a poem "the intentional fallacy."
Academic criticism of poetry became increasingly technical in the wake of the New Criticism. Schools such as formalism, structuralism and deconstruction sought to bring precise critical tools to bear on the question of how poetic language produces its effects. Some critics have held out against this trend towards scientistic objectivism, arguing that the personal experience of writing or reading poetry is supremely important. A notable exponent of this view has been Yale professor Harold Bloom. Others, such as Frank Lentricchia, have urged that poetry, like any other creative writing, can only be understood in the historical and political context of the times in which it emerged.
Poetry itself is shaped by the work of contemporary critics. The intense focus on self-contained poems which has dominated criticism for almost a hundred years has coincided with a decline of the long epic poem in favor of more concentrated lyric verse. The trend towards theoretical study of how poetic language itself works, in preference to an examination of the poet's motives, has coincided with experimental verse in which an interest in language seems to take precedence over telling a story or conveying emotions.