This post is partly a reaction to two recent blog posts that are related to the role of chance, particularly in evolution. The two blog posts are “Confessions of a Design Heretic” by nullasalus (at the Uncommon Descent site) and “Could God Have Set Up Darwinian Accidents?” by John Wilkins (at his Evolving Thoughts site).
I believe that both nullasalus and Wilkins are from Australia. Perhaps their posts are reactions to the southern hemisphere winter. Evolution is usually said as partly a result of chance, particularly as it shows up in random mutation. In his post, nullasalus says “I question the very existence of Chance.” In arguing that, nullasalus is supporting the idea sometimes expressed by theistic evolutionists, that God is at work behind the scenes, tweaking things so as to get the results that He desires. Wilkins is not proposing that theistic evolution is correct, but he is suggesting that it is “a coherent position to hold.”
The title of this post suggests that I want to relate the issue to metaphysics. So I should start by admitting that I don’t know what metaphysics actually is. And, from what reading I have done on it, I am not sure than anybody knows. For the purposes of this post, I shall take “metaphysics” to refer to a God’s eye view of our universe, or to how our universe would appear to an omniscient observer outside of the universe (if such an observer is even possible). It is sometime suggested that our universe could exist as a simulation on some sort of computer. If that is the case, then the computer program could be considered to be metaphysical laws that govern our universe (i.e. the simulation). By contrast, epistemic laws would be laws that we use from inside our universe, in order for us to describe our universe as well as possible. Similarly, one might distinguish between metaphysical chance (something that looks random to an omniscient observer outside our universe, and epistemic chance (something that we find it useful to call “random” in our descriptions of the world).
Personally, I am skeptical of any possibility of doing metaphysics. I see scientific laws as epistemic and I try to avoid suggesting that they are laws that actually govern the universe. Likewise I see our ordinary use of the word “chance” as a reference to epistemic chance and not to anything metaphysical.
With that prelude, I want to look at the post by nullasalus. When he says that he questions “the very existence of Chance”, I take him as questioning whether there is metaphysical chance. As I see it, there is no doubt that there is epistemic chance. And here I use “epistemic chance” for that which we find can be usefully modeled by the mathematical theory of probability. Personally, I have no position on whether there is metaphysical chance. Existing, as we do, within the universe, I see no possibility that we could ever find evidence to bear on the question of whether there is metaphysical chance. John Wilkins, in his post, seems to agree that the view of theistic evolution is coherent. I take that as agreeing that we have no way of proving that there is metaphysical chance.
Science works by trying to find ways of describing the universe that allow us to make useful predictions. When we say that a scientist has discovered a law, we could not mean that he has discovered a metaphysical law. For, as best I can tell, if there are such things as metaphysical laws then we could not have access to them and could not discover them. Whatever laws we do discover can only be epistemic laws, or methodological rules for us to follow when describing the universe. Scientists build new laws on top of accepted laws, in order to improve how well they can describe and predict. And when they reach the point where they can find no further way of expanding their repertoire of epistemic laws, they describe any variation (or unpredictability) that remains as chance (which I count as epistemic chance).
There are some in religious communities who want to say that some events have supernatural causes. By “supernatural” they seem to mean that the events are not predictable by epistemic laws. If science works about as I have described, then anything not predictable by epistemic laws will be considered by scientists to be due to chance. That is, it will be considered as due to epistemic chance. Scientists will still consider this natural. I commend nullasalus for understanding this, and for recognizing that those who want to make a case for divine intervention should look to what scientists consider to be chance as a possible place where that intervention might occur. However, I do wonder whether he has thought about how metaphysical free will could be possible without metaphysical chance.