Since antiquity, two formulations of the basic nature of man have coexisted in most major cultures. One is the conception of man as one fact of nature—in no fundamental way outstanding among the myriad varied facts of the natural world. This conception, in recent times articulated within the framework of the historical account of big-bang cosmology and archaeological anthropology, has the theoretical underpinning of thermodynamics and Darwinian-Mendelian biology. Currently, its limits are being stretched by the attempts of some sociobiologists to reformulate hitherto sacrosanct notions about man.