Like many aphorisms, the line by William Blake which gives Christopher Ricks the title of his new book, "Opposition is true Friendship", is more easily quoted than thought through, and more easily thought through than put into practice. With poets – and it is a small circle of five poets who stand here at the centre of Ricks's attention – "friendship" can sometimes look more like true opposition. One poet can know himself indebted to another without feeling himself to be so, still less acknowledging an obligation to express gratitude; and gratitude, as Ricks remarks, "is a nub", for while "the English language recognizes that there are such people as ingrates," we are also obliged to "face the fact that there is not a corresponding noun for someone who is truly grateful." Ricks is (as a critic can be) a master in the role of that impossible thing, "a grate, a great grate", but the evidence of so much of the poetry with which he deals must leave him in no doubt as to the solid foundation in fact of that other person, the ingrate.

The ingrate: ay, there's the nub. The two poets whose work presides over Ricks's study, Ezra Pound and T.S. Eliot, have each occasioned gratitude and dislike from other artists. Not, of course, that dislike is really the opposite of gratitude; but those who do not feel gratitude might point out that they do not therefore feel ingratitude for legacies which, they might profess, were never theirs to accept. The three poets read by Ricks "under the sign" of Pound and Eliot are Geoffrey Hill, Anthony Hecht, and Robert Lowell, and the argument of True Friendship is that these writers' expressions of complex gratitude to their elders illuminate something fundamental in the relationship, and the artistic achievements, of Pound and Eliot themselves. It is an intricate alignment which Ricks makes here, and one which involves (as he acknowledges) a certain amount of difficulty: not everybody is grateful to everybody else in this particular quincunx, and there are points of tension. But Ricks succeeds in bringing the three younger poets to bear on each other, and on Eliot and Pound, in ways that expose common concerns and preoccupations. Most notably, Ricks follows a thread of allusion and imitation that leads to Dante, whose example lights up – or perhaps casts a shadow across – the originality of the Modernist achievement in poetry.

Why Dante? For Ricks, the primacy of the poet of the Divina Commedia is made certain by the place given to him by Eliot, as the key poetic master and the greatest, most abiding influence on his own poetry. As so often in Ricks's work, Eliot is at the top of the pyramid: so, Pound partly inherits Dante from Eliot, while Lowell, Hecht, and Hill relate to Dante through Pound and ultimately Eliot again. Ricks does not say so, but his work makes it clear that for these poets Dante is essentially the Dante of T.S. Eliot. A climax is reached once Ricks can bring together Ezra Pound's late audio recording of Robert Lowell's Dante translation with Pound's own eventual assessment of Eliot's as 'the true Dantescan voice', after canvassing Hill's and Hecht's variously conflicted relations to both Eliot and Pound. Gratitude and ingratitude are both involved when, to adapt a line from the greatest drama of ingratitude in the language, the wheel is come full circle; Eliot is here.

The prime ingrate in this whole process – its Goneril or Regan, perhaps – is Geoffrey Hill, whose critical strictures on Eliot have become increasingly stern over the years. Ricks's task is a delicate one here, and his long chapter on Hill is as scrupulous as it is critically brilliant, asking us to compare the kinds of creative indebtedness to Eliot exhibited in Hill's poetry with the critical attacks made on Eliot in his prose. Undoubtedly, Ricks identifies places in Hill's poetry where Eliot is in earshot, and for which he is an essential stimulus: the criticism comes close, in fact, to suggesting that even Hill's more raucous recent verse, in spitting-distance of popular culture, is itself dependent on Eliot's example. Ricks reads all creative indebtedness as a species of gratitude, so that the gratitude is there in the poetry, whatever the poet himself might like to think, or however he might address his relations with Eliot in his own prose criticism. Here, Ricks has to declare interests of his own, and honourably does so in full, explaining how Hill has included him in the number of those misled by the later Eliot's "tone". The defence mounted here is a spirited and intelligent one, and remains a self-defence for as short a time as possible, but it still fails quite to defuse some of Hill's objections to the manners of Eliot's Four Quartets verse; and even Ricks's intense and sympathetic teasing out of the Eliot influence in Hill's poetry does not put those objections conclusively aside.

With Hecht, Ricks is on safer ground, for the American poet was usefully explicit both in his poetic uses of Eliot and in his critical thoughts about him. The exposition of Hecht's work here is masterfully done, and Ricks's eye for a good poem allows him to bring it under the very best kind of critical scrutiny: alert, sympathetic, and conceptually broad. British readers are seldom well-acquainted with Hecht (who died in 2004), but Ricks's close engagement might bring this elegant, subtle, and rhetorically poised writer more admirers. Hecht's sense of gratitude to Eliot was not straightforward, but Ricks follows the ins and outs of its expression with an extraordinary sureness. When Lowell's turn comes, Ricks is able to approach the Eliot relation by way of Pound, and he examines with beautiful precision and economy Lowell's poems about Pound incarcerated in St. Elizabeth's Hospital, and about Eliot himself. Lowell's gratitude to his elders, however, comes to seem almost indiscriminate; since it is gratitude, it is guaranteed Ricks's approving attention, but the extent of what it achieves artistically for Lowell is not so clear. Perhaps Lowell's verse incorporates too much of what his artistic life professed at length in the way of gratitude and affection: all "true Friendship", and a disabling of "Opposition". In that sense, maybe Hillian sourness achieves more than Lowellian blandishment.

These are, in the end (but not only in the end), questions of "tone", that term in Hill's criticism of Eliot which, like its counter-value of "pitch", Ricks claims not to understand. Eliot, too, would occasionally confess to not understanding things – the implication being that they were not, in fact, capable of being understood. Yet Ricks is supremely gifted in registering the "pitch" of literary language (a gift Hill has acknowledged). Such things have to be tested repeatedly, and the ground chosen by Ricks is that of the long second section of Eliot's Little Gidding, where a "compound ghost", modelled on one of Dante's spirits, addresses the poet in the aftermath of an air-raid. Ricks rightly sees this as a central piece of writing for Eliot's inheritors, and his detection of Pound within the ghost is persuasive and important. Yet the whole episode is also being offered as an exemplary scene of gratitude – more exemplary, indeed, than the Dante which lies behind it – and Eliot comes out of Ricks's interpretation as something of an ethical, as well as a poetic, hero. In the process, Ricks downplays the importance of the "compound" nature of the ghost's identity, and in particular he slights the significance of W.B. Yeats there. But then, Yeats is the element needed to make sense of Hill's relations to Eliot and Dante as well; of Pound's too, and perhaps (insofar as this can be ascertained) of Lowell's. Eliot's track-record as an ingrate with regard to Yeats might serve to complicate usefully the slightly too simple pattern of poetic hierarchy which Ricks now implies. Yet Ricks may well think (and if he thinks it, it would be as well for him to say so plainly) that Eliot had really nothing much for which to be grateful to Yeats.

For all this, True Friendship is a truly illuminating book. Better, it is a book of criticism which radiates not just intelligence and wit, but warmth, sympathy, and disinterested celebration. Ricks's criticism – unrivalled in quality now for decades, and palpably as strong as ever – remains that of "a great grate", who gives to poetry as much as he has received from it, and more.

© Peter McDonald

Christopher Ricks, True Friendship: Geoffrey Hill, Anthony Hecht, and Robert Lowell  Under the sign of Eliot and Pound, Yale University Press, 2010. £16.99 ISBN 978 0 30 0134292

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