How many poets are responsible for as many perfectly formed poems as Michael Longley? Of all of them, one of my very favourites is “Northern Lights”, an extraordinary combination of lightness of touch, harmony and grace with vastness and imaginative depth, all in a mere six lines.

In this poem, Longley remembers how when someone (“you”) woke him to show him the shimmering of the aurora through the window,

the northern lights became our own magnetic field –
your hand on my shoulder, your tobacco-y breath
and the solar wind that ruffled your thinning hair.

It isn’t stated but seems obvious that the person addressed is the speaker’s father. The placing of the hand on the shoulder is a paternal gesture. Longley associates tobacco with his father in a number of poems. Above all, as printed in Gorse Fires, “Northern Lights” faces “Laertes”, which describes Odysseus’s reunion with his father after his long wanderings. The electric spark of connection between the two poems adds to their huge imaginative power.

Looking at “Northern Lights” in isolation first, the three lines I’ve quoted take us through a series of giant imaginative strides. In one, we step from the beautiful sense of the charged closeness of the father and son as they stand in the window looking at the aurora to the idea of how the aurora effect itself is produced by the action of earth’s magnetic field on the particles from the sun forming the solar wind. Of course, the moment of special closeness between the two people is partly a response to the beauty of what they are seeing, but the way they are sharing their feelings also enhances the beauty for both of them, just as earth’s magnetic field creates the shimmering of the aurora. Then the physical intimacy of the hand’s warmth and weight on the shoulder and the tobacco-y breath are mirrored on a cosmic scale by the solar wind (reflecting the breath) and the way it ruffles the father’s hair (like a hand ruffling the hair of a child). With these ideas we step out from the close moment in the window to the vastness of space and of the physical processes that the window looks out on. However, because this vastness is seen in the humanising light of the solar wind’s mirroring the father’s breath and of the ruffling gesture, the vastness of the universe is not felt as chilling and diminishing human hopes and feelings but as supporting them. There’s nothing sentimental about this. After all, the physical universe is not only what sustains our physical life but also the occasion of all our feelings – like our awe at the beauty of the northern lights themselves.

The last of the imaginative steps that I want to focus on comes when we take “Northern Lights” and “Laertes” together. At the end of “Laertes” the old man falls weeping into the arms of his heroic middleaged son, who, Longley writes, “cradled like driftwood the bones of his dwindling father.” Behind the simile lies the idea of Odysseus’s voyaging, of the ships he’s lost, and the destruction of his raft by Poseidon. Peeping within the word “dwindling” is the image of a ship shrinking as it moves towards the horizon. Looming behind these ideas, and reinvigorated by them, is the old comparison of life to a journey. Odysseus’s wanderings on the way back from Troy are only an episode in this larger journey we all take and which, for Laertes, is almost over, to leave only driftwood and bones.

This idea of the larger journey seems to me to reflect back on “Northern Lights”. Flashing from “the solar wind that ruffled your thinning hair” is the idea of someone standing in the prow of a boat with the wind in his hair, but the boat is no longer Odysseus’s eyed ship; it is the whole planet earth as it moves through the wonders of space. And of course the two poems together show different and complementary phases of life: the time when the father is still in his strength although worn by his experiences (Longley associates his father’s smoking with his experiences in the trenches of the First World War) while the child is small and dependent, and the time when the father is old and weak, in need of the protection of the son, someone to be “cradled” himself, as if he’d become a child again.

Clearly there’s a great deal more that could be said about these poems both separately and together, simply on the levels of meaning and suggestion. What seems to me quite remarkable about them is how modestly these meanings emerge. There’s no sense of puzzlement before understanding, only a sense of the understanding deepening as one reflects, as if one were looking further and further through clear water. The other point I want to make is how much the wider reaches of meaning in the poem depend on allusion. There’s nothing particularly arcane about the allusion – all you need is to have been thrilled by the story of the Odyssey as a child – but it does make me fear for a future in which perhaps fewer and fewer children will have a basic imaginative exposure to the great tales of the past.

I would also say that while some years ago I was excited by the startling leaps of imagination in Muldoon’s poems, I now find myself much more profoundly satisfied by this kind of writing in which the strides, immense as they are, work as grounded enlargements of feeling and vision, not like whimsical sidesteps as they so often seem to be in Muldoon.