The first category is scientific knowledge -- the kind achieved through testing, weighing and probing. And within its competence, according to Collins, science is supreme. He is, for example, a strong defender of Darwinian evolution, a theory he calls "absolutely incontrovertible." Collins is particularly compelling when talking about the genetic evidence for the common ancestry of all living things -- the precise similarities between our DNA and that of other species, and the precisely located mutations that can only be explained by common origins. Religious texts, in his view, must be interpreted in light of these scientific facts.
But Collins argues that there is a second way of knowing -- a realm of morality and metaphysics that involves not physical proof but probability based on evidence. Some scientists assert that anything beyond the possibility of touching and testing is equally mythological -- from unicorns to God to morality to hope to meaning to love. Collins calls this kind of reductionism a "logical fallacy." By definition, science only yields information about the physical world, which does nothing to prove that the physical world is all there is. As human beings, we still seek to know why things exist and how we should live. Science is silent on these matters; we need not be. Collins contends that the moral law within us, and the fine- tuning of physical constants in the universe, provides "signposts" (not proofs) that lead toward God. (See Collins' book "The Language of God: A Scientist Presents Evidence for Belief" for his full and informed explanation.)
For Collins, modern science and Christianity are not competing answers to the same question; they are ways of thinking about two very different sets of questions, both of which should be taken seriously.
Collins' appointment says something good about the maturity of modern evangelicalism, which is starting to abandon some of its least productive debates with modernity. Criticisms of evolution, rooted in 19th-century controversies, have done little more than set up religious young people for entirely unnecessary crises of faith as they encounter scientific knowledge. In the running conflict of modern biology and evangelicalism, Collins is a peacemaker.
And Collins' appointment says something good about the maturity of President Obama. This move has invited criticism from the secular left. It is unlikely to appease religious conservatives who assume cynicism from Obama. But this seems to be a case where the president simply picked the best person for the job. In the process, Obama has affirmed something important: that anti-supernaturalism is not a litmus test at the highest levels of science.