Scan the non-fiction shelves of any bookshop and you will find yourself invited to follow in the footsteps of Flaubert, Tolstoy, Alexander the Great, exhorted to cast aside the daily grind and depart à la recherche de Robert Louis Stevenson, Ovid, Wordsworth. The itineraries speak enticingly of the harems of Persia, the wastes of Siberia and temples of the Orient; yet while we may be seduced by such exotic locales, they are little more than an elaborate sleight of hand that conceals the real journey being attempted: not an exploration of foreign lands at all, but the crossing of that most alien of terrains which lies between inspiration and insight, actualities and ideals - the unplottable space between author and text.

Arabesques: A Tale of Double Lives (Picador, 320pp; $50) sees Robert Dessaix venturing into this territory in pursuit of the Nobel-winning twentieth-century French author André Gide, tracing his life and works through the cityscapes of Morocco and Algeria, and in the countryside of northern and southern France. As in his earlier Twilight of Love: Travels with Turgenev, Dessaix proclaims himself uninterested in producing a straightforward scenic biography or literary tour guide. Arabesques is a distinctly more ambitious and wide-ranging project in which Gide serves as a "prism" to illuminate Dessaix's own philosophies, a work whose intricate conceptual and structural patterning owes (as the book's title suggests) much to geometric Islamic art.

Dessaix's interest in Gide the writer is evident throughout but - as with Turgenev - it seems to be the man who commands the real fascination. Dessaix undertakes a series of meditations that yield, and occasionally answer, their own questions: the significance of travel and the reasons we undertake it, issues of faith and religion, old age and love - all these rise successively to the surface, embellishing it with new textures and strands. Throughout these philosophical journeys Dessaix is less a guide than a fellow wanderer, and by the end we are left in little doubt of the book's function: to map, geographically and conceptually, not only the fractured figure of Gide but of Dessaix himself.

Arabesques is a book about travel, but it is not a travel book. It explores the life and works of André Gide yet is not a biography, and it tells us much about its author while not being an autobiography. Instead, the book is described as a travel memoir, and memoir is a slippery designation, with none of the rigid specificity of the biography or autobiography; it is simply the sum of things remembered, whether true or false. This is an ambiguity Dessaix revels in, the space in which his playfully self-aware narrative takes shape.

In a recent article, Dessaix argued that "Civilisation, after all, is memory ..." His list continued, but memory is foremost, a signpost to the belief that lies at the heart of his fascination with travel. Arabesques is a sustained working-out of the Nietzschean view that in travelling the individual exists in a privileged and reciprocal relationship with the past. Whether it is Gide or Dessaix seated on the carpeted floor of the kasbah, they acquire in that experience a sense of continuity, a communion with the past, that goes beyond merely informing themselves.

Any writing about André Gide - including his own - begins and ends with contradiction. A Protestant in a Catholic country, a homosexual who was devoted to his wife, and a wealthy socialist, Gide - in his work, and even more so in his life - attempted to reconcile his values and achieve a state of moral coherence. It is that inner tension which forms the basis of this tale of double lives, with Dessaix joining in the "game of hide-and-seek" as he elegantly characterises Gide's life and reflexive relationship with himself. What seems to interest Dessaix above all are the fault lines of a personality - the moments at which the core elements of education and instinct, desire and duty come into conflict, yielding an unstable duality and a shadowy other self. Dessaix explores these conflicts in geographical terms, setting the coldly formal beauty of the chateau at Cuverville that Gide shared in chaste companionship with his wife against the bustling intimacy of the kasbah, with its temptingly ripe young musicians.

Throughout Arabesques, though, the act of travel is always subordinate - or at least in the service of - inner peregrinations. A trip such as the young Gide's to Tunis, in 1893, or the young Dessaix's own pilgrimage to Rabat, in 1966, is significant not in itself, but in the "vantage point" that it offers on the mental and social rituals of home. While this is an argument as old as the urge for travel itself, Dessaix pushes it to new extremes, flirting with his notion that "Unless you have a double life to stop leading ... I don't see much point in leaving home in the first place." He explores the extent to which it is possible to give yourself over completely to the embrace of the Orient, to live directly in a state of "unmediated being". While such questions might hold good for Gide and his age, when deployed in the present they risk sliding into reductive polarity: the East, where "Life could be lived with a kind of immediacy impossible at home," sitting in direct opposition to the repressions of Northern Europe.

"It's all very well to cast off your European trappings and stand naked in the Tunisian sun, but what do you do with your newly naked self?" A pertinent question indeed after the ecstatic freedoms of "unmediated being", and one that Dessaix - with no domineering and devout mother to assist his choice - approaches with rather less certainty than Gide. Writing recently in the Age, he expressed his belief that "for the artist, art is in itself a redemptive act." Coming from one who describes himself as a Protestant atheist, "redemptive" seems a curious and charged term. It recurs in Arabesques in a more straightforwardly devotional context (the emphasis is Dessaix's own):

Every last loose thread of these six women's lives has already been lovingly gathered up and woven into the sacred tapestry of the Church. Their lives had been redeemed ... by being gathered up into the Church. For me ... there was no sacred tapestry to weave myself into, "sacred" being a word I had long since emptied of any meaning.

It is this craving for a tapestry, for a context into which to base both self and art, that seems to provide the answer for Dessaix. For him, the stuff of civilisation is "memory ... foundations ... language, learning", and the point at which society and culture collapse into decadence - "the engulfing blackness" - is not the forgetting of God or morality, but the forgetting of tradition. By following in the footsteps of his shadowy historical double and weaving his own narrative into the larger tapestry of literary tradition, Dessaix enacts a process of personal redemption, a philosophical pilgrimage that culminates in that most unequivocal symbol of affirmation for any wanderer: arrival. "I wake up. I know why I'm here."