He is, in fact, an important, even unique, poet, even if the value of his work has for long been treated as like his life, badly flawed or at best inadequate. Even commentators who professed to ignore biographical speculation were leery of making extravagant claims for the poetry. Hence, the commonly-accepted argument according to which Cowper, born too late to belong with the great Augustans, came too early to be identified with the Romantic movement. The best that could be said for him was that he discovered the foothills from which Coleridge and Wordsworth set out to conquer new, hitherto unattempted heights. Where he pointed they followed, but he was soon lost to sight in the mists of time. To be sure, there were The Olney Hymns, there were a number of individual poems such as “Lines Written During a Period of Insanity” and “The Castaway,” both of which confront his breakdowns, there were such domestic pieces as “On the Receipt of My Mother’s Picture Out of Norfolk” and “My Mary,” there was the comic “John Gilpin,” the songlike “The Poplar Field“, the meditation on “Yardley Oak”, and there was The Task; but somehow or other, though these poems found their way into anthologies, they were not enough to guarantee Cowper the status of major poet. And despite a number of recent attempts to rescue him from the heaviest charges brought against him, there remains a feeling that he is more interesting as a case study than as a poet of the first rank.He zooms in on Cowper's best poem:
Where Cowper does put blank verse to good use is in “Yardley Oak”, which seems to me not merely a great poem, but, in its ruminative manner, a work which anticipates much that can be found in, say, Coleridge’s “Frost at Midnight,” and Wordsworth’s The Prelude. “Yardley Oak” is a truly original poem. There had been nothing like it before. Its brooding, reflective tone, its wondering concern with the “shattered veteran, sixty-three years old” (at once tree and man), provides for the first time in English poetry a registering of mental process, of the fluctuating, unstable psyche from which much that is essential to later English poetry takes its cue. Only Hamlet’s soliloquies anticipate what Cowper does here and it may be that both Shakespeare and Cowper owe a debt to Montaigne and, in Cowper’s case, later French essayists.
To say that is, however, contentious. It ought not to be contentious to claim that “Yardley Oak” is a great poem. Yet how few readers recognise its originality. But then how few readers, perhaps, it has attracted. And perhaps, too, the comparatively few who have come across it have made the mistake of regarding it as a mere exercise in the kind of nostalgia which runs sweetly through “The Poplar Field”, with its lament for the “perishing pleasures of man.” “The Poplar Field” is a lovely poem, whose fluent anapaestic tetrameters are taken up by Wordsworth in “The Reverie of Poor Susan”, one of the Lyrical Ballads. But “Yardley Oak” is on an entirely different level.