Critical opinion on Pound's The Cantos is more divided than is the critical opinion on any other important modernist work, and the epic's critical fortunes have risen and fallen with time. Even during the half-century during which the work appeared in installments, readers and critics were widely divided on the poem's merits. As the critical literature on The Cantos is vast, here we will look only at how some of the most prominent writers and critics have felt about Pound's epic.

As the poem was being composed, even Pound's close friends and admirers were unsure about the structure of the poem—how it fit together and what it would look like as a whole. The Irish poet William Butler Yeats wrote in 1936 that "the relation of all the elements to one another, repeated or unrepeated, is to become apparent when the whole is finished... Like other readers I discover at present merely exquisite or grotesque fragments." Yeats felt that the poem had "more style than form; at moments more style, more deliberate nobility and the means to convey it than in any contemporary poet known to me, but it is constantly interrupted, broken, twisted into nothing by its direct opposite, nervous obsession, nightmare, stammering confusion."

T. S. Eliot echoed Yeats' criticisms, writing in 1946 that in '‘The Cantos there is an increasing defect of communication, not apparent when he is concerned with Sigismondo Malatesta, or Chinese dynasties, but, for instance, whenever he mentions Martin Van Buren. Such passages are very opaque: they read as if the author was so irritated with his readers for not knowing all about anybody so important as Van Buren." Eliot praised Pound's influence in the highest terms, but was less enthusiastic about his most important poem.

In 1950, the prominent English critic F. R. Leavis responded to Eliot's opinions on Pound. Like Eliot and Yeats, Leavis felt that Pound did not use the historical sources well. "Pound's various addictions,’’ he wrote, "speak the amateur: one cannot doubt his enthusiasm, but something else, surely, was needed to impel significant innovations in poetry." But where Eliot felt that Pound's importance as an influence was immeasurable, even if the meaning of his poem was opaque, Leavis felt that this "limited very drastically the kind of importance that can be attributed to The Cantos."

Pound's greatest defender among literary critics has been the Canadian Hugh Kenner, who wrote the first book-length study of Pound's work, The Poetry of Ezra Pound, in 1951, and who contributed the single greatest work of Pound scholarship, The Pound Era, twenty-one years later. In The Poetry of Ezra Pound, Kenner forcefully answered Pound's critics. After the appearance of the Pisan section of cantos in 1948, he wrote, "it is no longer easy... to dismiss The Cantos as either formless or irrelevant. Pound impinges upon the citizen of A.D. 1950 or whenever, not via his psychological tensions... but through a rational amalgam of morals and politics." Kenner's book was the first to argue that the epic was in fact an epic with form; Kenner made it possible for a large group of scholars to write on Pound without having to defend the poet on charges of formlessness or sloppiness. For Kenner, "Pound's structural unit in The Cantos is not unlike the Joycean epiphany: a highly concentrated manifestation of a moral, cultural, or political quiddity [the essential quality of a thing, its 'suchness']."

Although The Cantos were constantly criticized for being formless—and Kenner's work only provided a means of defense, it did not dispel all of the objections to Pound's poem—few...