A poet who avoids 'literature'; Collected Poems, 1943-1983, by C.H. Sisson. Manchester, England: Carcanet New Press, Ltd. 383 pp. $21.

C.H. Sisson didn't become a poet until he was nearly 30 and wasn't recognized as one until he was in his 60s. He is 70 now. A complete issue of the British periodical PN Review has borne witness to his standing in that country. A civil servant by profession, he is also a translator of prodigious energies (Catullus, Lucretius, Horace, Virgil, Ovid; du Bellay; ''The Song of Roland''; Dante), and the author of literary essays and a significant ''assessment'' titled ''English Poetry 1900-1950.''

It is nonetheless clear that, at least in the United States, C.H. Sisson could be better known.

His ''Collected Poems,'' recently published by Carcanet (which publishes almost all his books), provides our occasion.

The book is a hefty one and, we are glad to discover, built to last. It's contents span 40 years. Yes, there is some unevenness, as critics say; who among us has never bored a friend? But what Sisson calls (in writing of someone else) ''durable chat'' is to be found everywhere here. It can get pretty outrageous:

''Pliny, Horace, Cicero, talk to me;/ I am a dead language also./ The poetry owners cannot make me out.... Nor I them.''

No, Sisson's language is very much alive; he has one of the best ears in the business, as the last clause quoted suggests.

Sisson once wrote that ''the avoidance of literature is indispensable for the man who wants to tell the truth.'' Note well: the avoidance of literature. Put another way, ''it needs a poet rather than a mathematician to realize vividly the shadowy and elusive connection between word and fact.'' Today in the US the word ''life'' has become a political football: With all the scientific experts available for comment, there is still no consensus. Democracy is powerless in this regard. Furthermore, Sisson's duty to the shadowy realm takes him beyond the public realm into that of the self. This makes people uneasy. In one lovely passage he writes, ''The mind that hovers/ Over me like a hawk, is mine....'' Think on these things.

Sisson's assessment of English poetry in his century is opinionated but arguably correct. He has judged Yeats, Hardy, Eliot, and lesser fish by the measures of word, fact, and truth, and found too much literature. In his discussion of Yeats, he quotes a late poem and concludes, ''We learn nothing of the real old man, who took to reading detective stories and, if he ignored the death of his friends, did so not because he had a full-fashioned soul but out of selfishness, like the rest of us, and particularly the old.'' Judging Yeats by ''the daylight of natural speech'' may seem ingenuous to some, but Sisson earns his points, and teaches us, by placing art in the context of life.

Certainly Sisson knows the temptations of dour narcissism. If he writes out of nonbelief (four of his poems were included by Donald Davie in ''The New Oxford Book of Christian Verse''), he has only followed Isaiah: ''Cease ye from man, whose breath is in his nostrils: for wherein is he to be accounted of?'' Wherein? In Sisson's poetry! In ''Ham Hill,'' for example. Sisson's sense of place is acute. Compared to the scene-setting in Thomas Hardy, there is a desperation in Sisson's love for his neck of the woods. ''It is enough to be here,/ Not too much, enough;/ The equal of any love;/ That is why I am here.'' The writer of those lines has also written that ''my unrecognized style was made by sorrow.''

That style - and that sorrow (carefulness) - have helped Sisson avoid literature for over 30 years. That style is one of the chief ornaments of our language at the present time.

The black bulk of Sisson's poems stands as a witness and a challenge: a witness to the consolations of poetry, a challenge to all of us who claim to care for our fellow man. Goodwill without strict honesty is another con game. Reading Sisson is good for what ails us, left and right. He is a great purifying force.

Excerpt from 'Pocket-size Poems'

When I thought what I could do

Fifty years ago, I knew

There must be something I'd do well,

What it was I could not tell;

I had not done it, that was clear.

Nor have I now. How can there be

Ignorance enough left to me

For hope to feed on, when there isn't

Enough delusion for ambition?

''Collected Poems of C.H. Sisson''