[Gemini reveals] Tournier's astonishing gift for the exact, comprehensive, and economical description of complicated processes and objects….

Tournier exploits his details ceaselessly and explicitly for their symbolic potentialities….

But Tournier also has problems with detail. Vendredi…. reads in places like a repository of more or less bizarre descriptive tours de force. included despite the requirements of narrative cogency. The attempts to tie them in do not convince. The same is true of Gemini. It is arguably too long by a third. There are ingenious things in the last 150 pages, as Paul, seeking to restore the "geminate cell," pursues Jean, who seeks to destroy it, round the world. But the dominant impression, quite apart from the uncomfortable guide-book facts and figures on Venice, Iceland and Japan, is of heterogeneous material resisting integration into the main body of the book, Tournier is a master of the massively ramified conceit, but the conceit concerning meteors … set afoot in the last third of Gemini is one of his least successful.

Like Vendredi, Gemini is a novel of ideas, in that it is a novel devoted primarily to the elaborate and divagatory mise en scène of a particular idea, to the triangulation, at once whimsical and meticulous, of a particular conceptual locality. The two books overlap in their concerns, and Gemini contains several references to Robinson Crusoe, the (pointedly non-eponymous) hero of Vendredi. The principal subject of Vendredi is solitude and, obliquely, the nature of our need for others, for human otherness. Gemini, constructed like Virginia Woolf's The Waves as an irregular cycle of inner discourses by the various characters, develops directly the theme of the Other; of our search and desire, especially in sexual relations, for sameness of difference in others.

But Gemini is a novel of ideas not only because it is fiction in the service of speculation, but also because ideas are themselves the true protagonists. They are so because the human protagonists live through ideas. Tournier's exact flights of fancy are not narratorial interventions; they are his characters' reflections upon their own and each other's lives. And the real drama of their lives lies not in what befalls them—though this is dramatic enough—but in their compulsive theorizing about what befalls them. Time and again Tournier italicizes a phrase like geminate intuition and sets one of his characters to develop a whole series of cross-stitched reflections out of it.

It is the elaboration of these series of reflections that Tournier shows his greatest skill…. Apparent absurdity turns out upon inspection to be functional in some respect, to have a point; disparate oddments are assembled into sense…. [Tournier's constructions] work—or almost always. He has the French love of paradox, but he is rare among Frenchmen in making his paradoxes fertile, training them up with care and erudition, animating their initial awkwardness with the logic of common sense, making them concrete in the events of his characters' lives….

Sameness and difference, attachment, separation and loss. Tournier offers no general survey of this vast area, but develops highly idiosyncratic positions—those of his characters—deep within it, where complicated insights jostle with sententious prejudices. The genre is doubtless not to everyone's taste, but Tournier at his best is master at it…. [Tournier's distinction] is the ability to draw ideas and abstractions out of the concrete and particular….

In so doing he attains at times to the epic; and in a unique fashion. He gives a sense that the realm of ideas is indeed a realm, a place with an objective geography; a geography of epic proportions, rich in fictional possibility; not a place that is created, but one that is already, there, to be visited and travelled, and in which what happens is not of one's own choosing.