Shortly into Swithering you intuit you're in grown-up hands, and that the poet is writing from a set of concerns thought hard about before the poems were even begun. To "swither" means to fret or worry—what, exactly, is Robertson in a swither about? About the human fitin nature, is one answer; about the soul's fit in the body, is another. Behind both of these lies a parent agitation about the mutual insufficiency of spirit and matter. In maintaining an inconclusive pseudo-animism, the book is a powerful exercise of a variety of negative capability—only Robertson does not so much resist reaching after fact as lunge at it enraged, which both abases it and exalts it with attention. Animals and ruins, where human qualities are present but dilute, are the natural symbols of his poetry, and there are lots of each: creatures hunting and hunted, overgrown tool sheds, abandoned crofts, the deserted batteries at a seaside priory. Robertson flaunts the pathetic fallacy in the usual sense—the sea "sleeps," stones "dance," the wind "loots," and so on—but the poems are further filled with more active and charged transactions between the human and natural worlds, like a poorly-trained hawk, a selkie, and indeed Proteus himself.

Robertson's retelling of "The Death of Actaeon" is the first time in a decade I have cared about a Greek myth (Actaeon the hunter happens on Artemis naked, she turns him into a stag, and his own dogs run him down). If Robertson has a divinity, it is the dying Actaeon, an ephemeral compound of reflection and natural force, a mind expiring in comprehension of an immensity in which it has no part:

Drowning now,
his horned head reared, streaming, from the ruck,
as if a god was being born
—not a mortal soul transformed and torn apart.
The huntsmen looked around for Actaeon: calling
—each louder than the one before—for Actaeon,
as if he weren't there.
Should he not share this unexpected gift?

Heart trouble as a young man seems to have brought mortality home to Robertson (he writes about his operation for a replacement valve in "A Seagull Murmur," which will make you clutch your chest). He shows a sensitivity born of experiencing bodily fragility and a savagery born of rage at that fragility. These interact effectively throughout the poems, in part because the savagery does not let the sensitivity settle into a serene contemplation of the durable; they are not the same thing. His sense of human relationships is thereby harrowed, and in "Leavings" and "Donegal" he has written the best poems of fatherhood I have ever read.

Robertson shares with many Scottish poets the tendency to write at the same altitude, no matter the subject—cursing your neighbor and cursing god are essentially the same activity. This tendency has a salutary moderating effect, and weaves a poem about the death of Actaeon and (for instance) a poem about asparagus into a fabric of sensibility, where they might otherwise have drifted towards the overblown and the trivial. Hounded, and in a state of extreme self-alienation, Robertson has nevertheless found a way to write levelly, with concentration and without dissipation, coming away poem after poem with forceful answers for his predicament. Swithering is at root a book of existential weariness, but there is intense vitality in its endurance.

— D. H. Tracy