Anthropic reasoning is controversial among both theistic and atheistic scientists, and raises a host of difficult questions for both camps.
Anthropic reasoning within science has the potential to upset these entrenched positions, in that anthropic reasoning accepts that some attributes of our universe appear to be highly improbable, and that science should try to explain this.
Thus, I argue here that whoever takes anthropic reasoning to be scientific will have difficulty maintaining the claim that design, or at least apparent design, is nonscientific.
Anthropic reasoning brings the design argument not only back into physics and cosmology, but even back into biology.
Of course, since we have little idea what these probability functions actually are, we can draw only the conclusions that (1) anthropic reasoning entails the potential that intelligent life might be extremely improbable in a typical "observable" universe such as ours, and that (2) this probability is entangled with the probability distribution for the constants of the universe.
"In the broader perspective of a 'multiverse,'" he explains, "anthropic reasoning
acquires genuine explanatory force." Rees's book is an important addition not only to the popular cosmology literature but also to the history and philosophy of science itself.