Biological reflections by the distinguished French evolutionist on the past and future of that astounding piece of protoplasm, Man. Now in his seventies, Rostand -- son of Edmond, the poet-playwright -- confronts his own qualms and wonderment at the ""biological adulteration of the person."" Is Paul, whose life has been extended with Peter's transplanted kidney, now ""Peterized""? As homografts become commonplace and cybernetics imitates human organisms are we doomed to a loss of singularity, to ""thingification""? And what are a scientist's or a doctor's responsibilities toward the congenital idiot, the malformed embryo, the ""decerebrated"" living dead? Can we delineate the ""limits of the human"" and establish criteria for ""biological unworthiness""? Rostand wrestles with the morality of science, the social ethics of medicine and the ancient dualism of mind and body from the vantage point of DNA molecules, genetic engineering and brain surgery. Ontologically, where do we stand now that a human is ""capable of being divided, taken apart, fragmented, and partially replaced, manufactured and imitated""? -- even the great Pascal would have been perplexed. Au fond a materialist who rejects the transcendent soul and the comforting illusion, Rostand nevertheless believes ardently (""to the point of fetishism"") in the sanctity of human life -- ""the closest thing to an absolute in our civilization."" But as we learn to efface pain, sickness and death will we be plus ou moins homme? Rostand revels in the paradoxes of science and philosophy, pondering the imponderables with considerable avuncular wisdom.