Klein's best poetry did, evidently, get into his [earlier] books. The lesser work [also included in The Collected Poems of A. M. Klein] is interesting, especially the "Radical Poems, 1932–1938", for the light it throws on Klein's growth. But most readers will return to Hath Not a Jew … (1940) and Poems (1944), and will agree with [the editor] Miriam Waddington that in his last volume, The Rocking Chair (1948), Klein "finally found his true tongue and voice." It is in the late poems that the elaborate rhetoric, personifications, archaisms and stylized ejaculations enter into a more vital tension with the energy of ordinary speech: and Klein's unique poetic style comes into its own.

There is disappointment in store for those who want more understanding of the legendary twenty years' oblivion which set in and stifled Klein's genius just when it had reached its maturity in the early 1950's. Would those unpublished poems, after all, give us the key? "I lift my visor. Know me who I am," say the only words from the manuscripts Miriam Waddington allows us. Certainly the published work lifts no visor. Klein's is characteristically public poetry…. Klein seems never to have discovered a way of dealing poetically with the depths of his own inwardness. The confessional hints he gives are startling, dismaying, like accidental rifts in the substantial if polluted surfaces of society and history, through which are glimpsed bottomless abysses of private horror or nothingness. To go there is to plunge out of human reach…. [The] best of Abraham Klein's poetry surely deserves to stand with the best Canadian poetry: intelligent, witty, compassionate, eloquent, comprehensive, exuberant, though unfashionably decent, the poetry of a good Jew (a phrase Klein could use both warmly and bitterly) and a good man. But it has its place on the other side of a great divide: no longer modern, no help to self-obsessed writers (younger or older than he) for whom the dilemma is how to find forms and words which will hold together private and public realities that have stretched too far apart and racked so many to the breaking point. In the heart of Klein's poetry there seems to be a blank, a silence, as if he saw more than—out of fear and for love of his fellow men—he cared to tell us.

F. W. Watt, "Fruits of Stifled Genius," in The Canadian Forum, Vol. LIV, No. 646, November-December, 1974, p. 18.