Charles Tomlinson's poetry has benefited, perhaps perversely, from his frustrated interest in a career in cinema and his often frustrating progress as an artist, and almost fulfils that vexatious Horatian dictum, ut pictura poesis. Firmly categorized now as a poet of landscape, Tomlinson has for over forty years produced his careful, Impressionist pieces, combining a painter's precision and sensitivity with the cinematic facility for recording the passage of time. Whether in the free verse which formerly suited him so well for Mexican and American vistas, or in the more formal metres which he handles with extraordinary fluency, Tomlinson continues, in The Door in the Wall, to concentrate on the minute details of change and flux in landscape, which are played out against the more reliable constancies of seasonal iteration and immutable landmarks.

There is a reverence in his work which has always been close to religiosity—one poem, "Blaubeuren", breaks startlingly into something like prayer—but his are resolutely secular devotions, closer to Gaia than theism or even humanism. From his earliest mature work Tomlinson sought a sublimation of his own ego, "putting aside some of the more violent claims of personality". Having eliminated himself from his enquiries, Tomlinson invests his poems with a sensibility rather than a presence, refusing to privilege the relationship between man and environment over the myriad relationships within that environment: the poet as component rather than colonist.

The Door in the Wall, as the title implies, maintains a focus on the unstable thresholds of a world in motion, delighting in the tension between boundary and passage, often drawn in terms of forces such as light or snow, which disregard or even recast landscapes and thoroughfares. "The Operation", a description of a forest clearance, elevates the labour to an artistic process of honing and alteration, elsewhere an elegantly rendered Neoplatonism tests the potential and limitations of Tomlinson's poetic metamorphoses, aspiring to a vision beyond the empirical: "we live in a place always just out of reach." His suitably leaky stanzas, bounded by gentle enjambments, carry the filtered light and sound which washes through buildings, streets and unfenced spaces; Tomlinson is quietly intoxicated by the luminous and material traffic which paradoxically confirms "the integrity of the planet." His Eden is an attitude of undamaging appreciation, not a place, and he cites Octavio Paz as saying "there are no gardens … except / for those we carry with us."

This husbandry, which carries a tacit political or philosophical correlative, earns respect through the weight of Tomlinson's own regard for the subjects he presents with such dignified and attentive detail. It is a stance which has led to accusations of coldness, because Tomlinson's passion is communicated in an anti-Romantic spirit, which equates extremity of faith or feeling with arrogant violence. The Door in the Wall retains traces of this concern—poems recalling Paris in 1969, Siena in 1968—but without the vigour with which Tomlinson used to employ assassination as a motif for senseless homicide in the name of Utopia. When he does refer to Trotsky, in support of his distinctly personal credo that colour might determine one's choice of homeland, the passage sounds faintly batty read outside the context of his previous work: "I think when Mercader killed Trotsky, / the colours of that garden in Coyoacan / counted for little …"

These lines are taken from a letter to Paz which discusses their reasons for remaining in their own countries. Tomlinson's decision not to emigrate to the United States is couched in pedagogic terms; "I thought that I could teach my countrymen to see / The changing English light, like water / That drips off a gunwale". The tense of the sentence perhaps implies the thwarting of that particular desire. There is an otherworldly quality about Tomlinson's Zen aestheticism which has sometimes made him seem almost uninterested in people and history; and his latest work does nothing to dispel this impression of unease. His "Ode to San Francisco" remarks "It is strange to live in a city where one third of the males may die of the same disease," in an infelicitously curious tone, not helped by the doubtlessly well-meant fogeyism of "I used to think it gay / (that damaged word)."

Perhaps it is apt that so self-effacing a writer is most obtrusive in his parentheses; the occasional pettifogging footnote or disruptive qualification can only partly be attributed to a nervous regard for precision. The volume contains more of these tics and clumsinesses than one is used to from Tomlinson. "At Hanratty's" heavy-handedly extends his interest in mutability to a New York of immigrants learning the roles of a new nationality after an unusually prolix and rambling disquisition, and "Crossing Aguadilla" is no less programmatic in its final juxtapositions of McDonald's and a "Jesus is coming" sign. These are relatively trifling points, and to quibble over Tomlinson's treatment of human beings is not unlike criticizing Turner for not painting portraits. The majority of these poems, as always, command the reciprocation of their own painstaking contemplation, the beauty of their visions more than matched by the skill of their execution.