There's something of the shadow puppeteer in Don Paterson - reading his poems, you don't know what's real and what's illusion; they play with the reader's perceptions and sense of perspective, so that you aren't quite sure whether what you're looking at are the moving figures themselves or the backlit projection screen.

At their best, this gives them a curiously disorienting quality, like looking at a photographic negative, in which the world - or its representation - has been turned inside out. "The Swing" is seemingly a poem of loss. The tone is unmistakably one of absence and regret, though precisely what is lost is initially unclear. The poet describes putting up a swing for his children - "for the boys, / for the here-and-here-to-stay" - but, having finished the job, sees upon it only "the child that would not come". The sense of aloneness is clear in the way the world of the poem coalesces tenderly around the shape of the missing child, reconfiguring her absence as a sharply felt presence: "I gave the empty seat a push / and nothing made a sound / and swung between two skies to brush / her feet upon the ground".

The paradox behind that simple-seeming phrase, "nothing made a sound", which can be read two ways - is there no sound, or is there a sound that is made by "nothing"? - is typical Paterson. In "Parallax" (one of two poems here in memory of his friend Michael Donaghy) he again turns common-sense notions of perception upside down. The poet stands, "like a man in his own book", looking at the moon and is "encircled by / the blindspot of its look"; the viewer is no passive recipient of sense impressions, but rather "the long pole of my gaze / was all that made it turn". The moon is "rolling out and rolling out / its white path to the self".

That awareness of the viewing, thinking self is evident throughout Rain, Paterson's first collection since 2003's multi-awardwinning Landing Light. Where that book focused mainly on the poetic self and its various relationships with others - parents, lovers, children - here Paterson is more concerned with a kind of Platonic inquiry into the self and its relation to the physical world. "When you lift your hand or tongue", he asks in "Motive", "what is it moves to make you move?" The answer, in this poem, is a half-glimpsed deistic force, something transcendent but impersonal and quite indifferent to the petty concerns of humankind. We may be, each of us, trapped inside our own consciousness, yet there is something that "hurries on its course / outside every human head".

The poem that follows, "The Day", takes this further, with two speakers debating their existential aloneness: "'We're each of us a separate universe. // We talk, make love, we sleep in the same bed - / but no matter what we do, you can't be me.' [...] 'You're saying that because / the bed's a light-year wide, or might as well be, / I'm even lonelier than I thought I was?'" Here Paterson has no truck with "this crap / of souls and gods and ghosts and afterlives". But the one thing that can bridge that vast gap between two people - or seem to - is love, though it's always contingent, a matter of chance: "even in this nothingness I found you; / I was lucky in the timing of my birth."

Elsewhere, however, even that bare consolation is wanting. "We come from nothing and return to it," he writes in "Phantom", a longish elegy for Donaghy that is Zen-like in its bleakness. But, as in "The Swing", that nothingness doesn't exist out there, beyond ourselves; it is a something - albeit impersonal - that can be defined in terms of human consciousness: "We are ourselves the void in contemplation. / We are its only nerve and hand and eye."

The humour that so strongly marked Paterson's earlier collections appears to be in short supply here, but in the midst of these sharp and sparely lyrical miniatures there's a long and very funny poem that takes the form of a fan letter to one Natalie Beridze (aka TBA), an electropop singer/songwriter from Georgia. Paterson, himself a skilled musician, is clearly well up on the language of techno-geekery, and in this piece he seems determined to match William McGonagall (a fellow Dundonian) for absurdity of line-length and dogged prosiness: "I have also deduced from your staggeringly ingenious employment of some pretty basic wavetables / that unlike many of your East European counterparts, all your VST plug-ins, while not perhaps the best available / probably all have a legitimate upgrade path / [...] which makes me love you more, demonstrating as it does an excess of virtue given your country's well-known talent for software piracy ..."

Amusing as it is, the poem threatens to unbalance the book, which otherwise deals with more elemental concerns. However, some excellent loose translations from Robert Desnos, Antonio Machado, César Vallejo and others, along with the Donaghy elegy and the title poem that round off the collection, restore the disconsolate equilibrium: "forget the ink, the milk, the blood - / all was washed clean with the flood / we rose up from the falling waters / the fallen rain's own sons and daughters // and none of this, none of this matters." The master of shadowplay demonstrates again that he remains clear-eyed about the representations he so artfully contrives.

 To order Rain for £11.99 with free UK p&p call Guardian book service on 0330 333 6846. Listen to the podcast of an interview with Don Paterson at guardian.co.uk/audio