In the Booknotes to this journal's Volume 5 (1990), at page 259, M. Ruse says of the Design Argument that, after Darwin, it was "stone dead -attempts to resuscitate it by biology-ignorant physicists under the guise of the anthropic principle notwithstanding (Barrow and Tipler 1986)". This strikes me as unfair to Barrow and Tipler, and to the Anthropic Principle, and to the Design Argument.
The Anthropic Principle was enunciated by B. Carter (1974) who made clear that it was not specifically concerned with anthropos, humankind. When Carter wrote, "the anthropic principle to the effect that what we can expect to observe must be restricted by the conditions necessary to our presence as observers", it was the prerequisites of observership, and not of lovable two-eyed human observership, that he had in mind. Further, his idea that observations must be restricted by conditions in which observers are possible, is not the controversial notion that observers -let alone human ones -were somehow forced to occur. And though Barrow and Tipler do at times emphasize human observership, while at other times they suggest even that observers of one sort or another were forced to occur, they never defend the bizarre theory that human observers evolved with biological inevitability. They point to how very difficult it may be for observers of any sort to evolve even on ideally suitable planets. They calculate (p. 566) that one might have to travel ten to the power of eight hundred light years, if indeed the cosmos stretches that far, before finding other beings recognizable as homo sapiens. Contrast this with the mere circa ten to the power of ten light years which is the distance light can have travelled towards us since the Big Bang.
Barrow and Tipler have three reasons for thinking that observers are rare. First: they note, citing "Dobzhansky, Simpson, Francois, Ayala et al. and Mayr", a "general consensus among evolutionists that the evolution of intelligent life is so improbable that it is unlikely to have occurred on any other planet in the entire visible universe" (p. 133) -i.e., in the cosmos out as far as the horizon, at circa 1010 light years, to all that is now visible from Earth. Intelligence, they comment, may bring few evolutionary benefits. A sophisti-