The Book of Atheist Spirituality rejects all claims of the supernatural. Spirituality of every variety is entirely contained within nature; he believes that the "mysteries of the universe" are not evidence of the existence of God or gods, but of the inevitable limits of our knowledge.
The English edition of this book is subtitled "an Elegant Argument for Spirituality Without God"...Comte-Sponville, uniquely for a fashionable French philosopher (his A Small Treatise on the Great Virtues has been translated into 25 languages), comes across as a modest bloke, anxious not to offend believers.
His demolition of the traditional "proofs" of the existence of God is indeed elegant. So is his alternative to supernatural belief, in which the Buddha (who, it is easy to forget, was an atheist) shakes hands with Spinoza, Wittgenstein and, less predictably, Jesus and St Augustine.
At the heart of Comte-Sponville's argument lies a redefinition of spirituality: we are spiritual animals, he says, by virtue of our ability to reflect on the infinity of nature and to act on those reflections with love. Love will remain when faith and hope have passed away, he says, which has a familiar ring to it.
According to Augustine, one of the reasons love is greater than faith and hope is that neither of the latter two will be necessary when God reveals himself. Comte-Sponville's reasoning is different, and less easy to follow, but he cites Augustine with admiration and gratitude. And that in itself is important.
The Book of Atheist Spirituality will do more good than harm. Christians are unlikely to read it or, if they do, lose their faith as a result. Its target market is the fast-growing constituency of young, middle-class atheists or agnostics who have absorbed from Richard Dawkins and Philip Pullman a patronising disregard for the Christian heritage of the West.
Comte-Sponville tells them to uncurl their lips. He sees "a degree of stupidity" in contempt for religion.
Since it is both man-made and ineradicable, in his opinion, it is silly to detect in it some unique wickedness - and even sillier to try to turn the sins of the Inquisition (it's always the sins of the Inquisition, never those of Muslim Spain) into an argument against the existence of God.
He adds: "Humanity is far too weak and life far too difficult for people to go round spitting on each other's faiths."