[Gemini] is the work of a mind expanding under the apparent beneficence of praise, performing with both an obligation to grandeur and a licence to self-indulgence. The grandeur is frequently impressive, the project kept up with remarkable stamina: but the self-indulgence, as well as weakening the structure, also undermines the confidence of the reader. Tournier is not a man to make a point once if he can make it a dozen times, or to use one word if he can use a thousand. Subjected to this immense performance of reiterative loquacity the reader increasingly responds with both 'I know …' and 'What, really, does it mean?'

The novel's meaning emerges from its study of twinship, Jean and Paul Surin are twins so identical that even their father cannot tell them apart; their physical similarity is coupled with an emotional and psychological identification, not of sympathetic reactions but of a shared geminate intuition—a phrase always printed … in italics.

Tournier's technique is to refract this geminate experience through the lives of others who are striving for its perfect reciprocity without the advantage of twinship. Jean and Paul are outsiders in the quality of their sensitivity and they celebrate themselves in a number of fantastic theories—for instance, about their congential innocence, all single children having murdered their notional twin in a prenatal enactment of Cain's fratricide. The novel's form, in which several different persons expound their theories, creates the semblance of a free expression of autonomous personalities, though we rapidly come to see that the novelistic circumstance is a mere pretext for an orchestration of ideas in which all the speakers … sound exactly the same. The novel is about identity without being about, or even much bothering with, the fictional machinery of character. Certainly, the people represent different intellectual positions, but subjected to the figurative counterpoint of the structure, none of them has access to our sympathies. The more the separation of Jean-Paul becomes the excuse of an abstract or pseudophilosophical argument, the less the dogmatic geminate intuition and the alienating light of a non-twin's reaction can register at a human level…. Whatever its fantasy, and however amusing (or unamusing) its laborious jokes, its aim is a serious and psychological one. But there is something unsettling and unconvincing in its mode of asseveration, for where Proust reveals his verities through a playing of the imagination on society, Tournier strives for his in a hypnotic reiteration of premises and positions unsupported by naturalism or even common sense: hence the wearisome feeling of familiarity with the ideas, and a lack of transmitted conviction in their meaning. The most rationally convincing parts are those closest to social history, the descriptions of the twins' father and his search for heroism in the Resistance; this realism is identified with the morality and normality of the world which the principal narrators leave behind them—the twins in their odyssey and Alexandre in his life among the great rubbish-tips of France and Morocco and his pursuit of boys. In the twins self-interest has an inevitable ambiguity, but Alexandre is a tyrannical egoist who, for Tournier, poses the problem of the interesting presentation of an irremediable bore. His twinship theories about same-sex love are as unimpressive as his eulogies of rubbish and Genet-like rejection of the 'heterosexual desert' are monotonous; his philosophy and sociology of homosexuality dissipate their wayward and essentially epigrammatic cleverness in Tournier's besetting overkill.

The novel works by massive rhymes and juxtapositions, and the later wanderings bring into play the metaphorical attributes of a multitude of places, sometimes …, no more than the sum of their clichés. It is here that character is least relevant and that the opportunism of a kind of symbolic picaresque dominates: its climax comes as Paul tunnels under the Berlin Wall to join Jean, and is badly injured. The new Berlin becomes a symbol of the new existence of Paul, his legs amputated, his own person split in two. His earlier physical ubiquity is replaced by free-ranging imagination and minute perception: in his immobility he contemplates life as if it were a miniature Zen garden in which only the eyes may walk. Like Cain and Romulus founding cities after their fratricides, Paul's eventual achievement of singleness is accompanied by the sublimation of his physical self into a new state of identification with the natural world, with the meteors—manifestations of a sublime logic independent of humanity. Whether all this means anything, or is simply an overblown caprice, may depend on the susceptibilities of the reader.