In a recent New York Times op-ed, evolutionary biologist David Barash recounts telling the undergraduates in his animal behavior class that evolutionary science has "demolished two previously potent pillars of religious faith and undermined belief in an omnipotent and omni-benevolent God." While I concur that there is a tension, a conflict, even, between evolutionary science and some religious beliefs, Barash's claims of demolition are more "op" than "ed," I'm afraid. I will deal with two of his claims in this essay and a third in a followup essay.
Barash claims that science has undermined the argument from complexity (the claim the existence of complex organisms requires a supernatural creator) and belief in human centrality (the belief "that human beings were distinct from other life-forms, chips off the old divine block"). Let's take them one at a time.
Evolutionary science, Barash claims, is an "entirely natural and undirected process," involving "random variation plus natural selection." Random variation and natural selection combine "to generate extraordinary levels of non-randomness." Here I think he's mostly right. Random variation and natural selection are indeed natural processes, ones that have produced every living thing, including human beings. This alone would create a problem for certain kinds of religious belief -- beliefs about a special, divine creation of each species about 6,000 to 10,000 years ago. On this, Barash and I concur.
Here's where we part company. Science, as science, says nothing whatsoever about whether or not this process is directed. Any claim to direction (or not) is metaphysical, one that goes beyond what can or cannot be known about the physical world. (Such claims are part of metaphysics, not physics.) Rejecting such guidance requires philosophical speculation about processes and/or entities that operate (or don't) beyond the natural realm.
Barash should have stopped and told his young and impressionable students that he was no longer doing science and was beginning to speculate philosophically. He should have confessed that he was now opining as a philosopher not teaching as a scientist. He should have conceded that his pronouncements were philosophical, not scientific. He should have stopped, cleared his throat, and said something like this: "Before I was using accepted and acceptable scientific methodology, but now I'm just guessing. My guess is that the process is unguided."
Science is, by its very nature, methodologically natural. That is, it looks for the natural processes that are operative within nature, eschewing anything that smacks of the supernatural. And rightly so: In setting aside supernatural entities and forces in its enquiries into the natural world, science has achieved a remarkably deep understanding of the natural processes involved in nature. But in setting the supernatural aside at the beginning, it cannot reasonably assert that, in the end, it has disproved the supernatural.
Suppose a group of brilliant mathematicians had decided to leave out the odd numbers in all their calculations. And suppose, after years and years of remarkably fruitful mathematical advancements, one of the even-numbered mathematicians informed a group of young and impressionable undergraduates that mathematics has demolished the odd numbers. Such a pronouncement would and should be treated with guffaws. If, as a matter of mathematical methodology, you leave the odd numbers out, you are not going to end up with odd numbers.
Given that Barash's very methodology precludes from the outset speculation about what lies (or doesn't) beyond or outside nature, one shouldn't put much stock in his religious pronouncements.
What about the so-called "illusion of centrality," the claim that humans are somehow unique and special, perhaps even godlike ("chips off the old divine block")? Again, evolutionary science simply has nothing to say about this. We are, for sure, animal-like, having descended from animals and all that. Barash's course in animal behavior is likely to reveal that, as Darwin put it, "Man bears in his bodily structure clear traces of his descent from some lower form." But are we more than animals? Were we created in the image of God? Are we chips off the old divine block? Again, the biologist, as biologist, is simply in no position to answer these metaphysical questions one way or the other. He can offer his personal opinions about supernatural reality, but as a biologist he lacks the tools one might need to make such a judgment (as a scientist).
Once again, he should have stopped after offering well-established science, science based on widely accepted methodological principles, and then informed his students that he was now just guessing.
Barash leaps into philosophy under the guise of scientific authority. But make no mistake: His religious pronouncements carry none of the authority of hard-earned science. Barash ventured outside the domain of science when making imperialistic claims about unguided processes and illusions of centrality. He, like Richard Dawkins and Lawrence Krauss, slips from the scientific mode, where he is an authority, to the philosophical mode, where he is not.
Biologists, being methodological naturalists, can make few scientific pronouncements bearing on religion. (As mentioned in the previous paragraphs, they can make legitimate claims about the age of the Earth, the natural processes involved in the "creation" of species, and the animal ancestors of human beings -- where those conflict with religious claims, religions have a serious problem.) Philosophers, sadly, aren't much better equipped for settling metaphysical questions. Philosophers, unlike biologists, have no agreed-upon methodology or set of data; thus, philosophers have not achieved the rational consensus one finds in the sciences. Philosophers cannot rightly claim to have demolished supernatural beliefs (though some do). Moreover, one finds among philosophers a very wide range of beliefs about what exists beyond or outside nature. Some say God, some say the Good, some say Beauty, and some say Numbers (and some reject one or all of the above).
Philosophers have no privileged access to what lies beyond nature. There is no such thing as philosophical consensus. There is a great deal of spirited and sometimes acrimonious disagreement but little to no consensus.
As a philosopher, I lament our philosophical situation (which is, I believe, part and parcel of the human condition). I wish that we had a method, as scientists do, one that would settle once and for all the nature of ultimate reality. But we don't.
Hence, assured pronouncements about the nature of ultimate reality are little more than bluster on the part of the pronouncer -- even if the pronouncer is a scientist.
As with most philosophical pronouncements, Barash's opinions, then, should be taken with a grain of salt, not as the confident deliverance of science. My suggestion: Barash should share his hard-earned scientific knowledge and keep his metaphysical guesses to himself.
Finally -- and this should not pass unremarked -- when making condemnatory religious pronouncements in a science class, Barash is an academic bully. He is a highly trained and seasoned scientist, and his young students are new to the field; they are weak, but he is strong. As such, they are unlikely to be able to tell when Barash is teaching science and when he is just gassing. The power imbalance is astounding. U.S. universities should not abide such blatant intellectual bullying in their classrooms.