Heaney has plenty of magic in his poetry: that moving on from the first unusual word, the right placing of which is probably in the gift of every poet, to a second one which clinches the insight, and thence to the confirming vision which makes the poem memorable.

You can see this in the first poem in [Field Work], entitled 'Oysters.' Clearly, such a mundane subject is going to be made to yield dividends in seriousness, even solemnity. He says his tongue was 'a filling estuary' and that he tasted 'the salty Pleiades.' In the next stanza the sigh of ocean is given the adjective 'philandering'; the poem moves to celebrate friendship in oyster-eating and a further stanza recalls the privileged Romans who carried oysters over the Alps 'packed deep in hay and snow.' The final stanza picks up that touch of philandering, and turns...