In his recent post “The four tiers of Intelligent Design – an ecumenical proposal” at the Uncommon Descent blog, vjtorley has attempted to define “natural” and “supernatural.” In a comment, I pointed out what I saw as some problems with his definition. And vjtorley has since asked how I would define them. So this post is intended as a reply. It is a bit too long to post as a comment on UD.
“Naturalism” is sometimes defined as the thesis that nature is all that exists. Or, alternatively, everthing that exists is part of nature. As a mathematician, I have problems with that definition. I do not see mathematics and mathematical entities as part of nature. We might try a broader definition such as “everything that exists is either part of nature or arises out of nature.” And that would presumably include mathematics as arising out of nature, even if not part of nature.
That broader definition is far better, though I still do not subscribe to it. The remaining problem, is that for naturalism to make sense under that definition, we would have to know what nature is. However, it seems to me that we are still discovering what nature is.
It seems to me that in practice, if we ever observe anything at all, we will say that what was observed is part of nature. And if naturalism just means that, then it doesn’t really say anything much at all.
When I look at vjtorley’s definition of supernatural, I have the sense that he wants to say that the supernatural shows up as violations of scientific laws. Many, but not all theists seem to want that kind of view of the supernatural. But there’s a problem with that approach. It is not realistic when we look at how science actually works. Let me illustrate with Ohm’s law as an example.
Ohm’s law, which applies to electrical circuits, says that V=IR, or voltage is current times resistance. Let’s look at two possible interpretations of Ohm’s law:
Interpretation (a): The voltage of an electrical circuit is directly proportional to the current flowing in that circuit, with the resistance being the constant of proportionality.
Interpretation (b): The resistance of an electrical circuit is defined to be the voltage divided by the current.
The trouble with interpretation (a), is that there are many circuits for which it is false. My suspicion is that it is false for all circuits with the possible exception of where superconductivity is occurring. Say that a circuit is linear if the voltage is proportional to the current. Most ordinary circuits, such as your house wiring, are at least approximately linear. Other circuits are non-linear in very pronounced ways. Our modern digital electronics is highly dependent on non-linear circuit components. If we go with interpretation (a), and if we use vjtorley’s definition of “supernatural”, then our digital computers would be supernatural.
Interpretation (b) is better. Ohm’s law is very important in electronics, with interpretation (b). In practice, resistance is defined as the derivative dV/dI. The difficulty that interpretation (b) poses for vjtorley, is that not even God could violate Ohm’s law, because it is a logically necessary truth. There might be circuits for which it is useless, but there could not be circuits for which it is false.
If we go by interpretation (a), then Ohm’s law is false, is well known to be false, but is a useful idealization. It cannot be refuted, because idealizations are not refutable. On the other hand, if we follow interpretation (b), then Ohm’s law is a logical truth. And again, it cannot be refuted. It seems to be true of most scientific laws, perhaps all of them, that they are either useful idealizations or they are logically necessary truths. Either way, they cannot be refuted. This is, I am sure, quite frustrating to the critics of evolution. They keep coming up with what they think are refutations of neo-Darwinism, but that theory is able to accommodate their evidence and is not refuted.
And now let’s look at the supernatural. From what I have argued thus far, it looks as if it would be unworkable to attempt define supernatural in terms of violation of scientific laws. The natural seems all encompassing, and that does not leave much room for the supernatural. My personal opinion is that theists make a mistake when they try to rely on the supernatural. They would have been wiser to define God to be nature itself.
If you still want a supernatural, then it seems to me that the only possibility is to have a supernatural realm which is distinct from and separate from the natural realm, and which could influence the natural realm only by natural means, though perhaps unpredictable natural means. This is, I think, similar to the view taken by theistic evolutionists. And they take that view because they know their science well and they know that such a view of the supernatural is the only one that could be consistent with science.
After defining naturalism and supernaturalism, vjtorley went on to discuss miracles. He attempted to characterize miracles as supernatural in the sense of violating scientific laws. However, as I have argued above, such is impossible. Nothing supernatural could ever be observed. I don’t think that there could be any easy way to define miracle. The closest you are likely to get, is the occurrence of events which some people see as miracles while others see as entirely natural. And that’s pretty much what happens today when somebody announces a miracle.
A few months ago, a commenter at one of the blogs (probably Jerry Coyne’s blog) said that science refutes the resurrection. Well, no, it doesn’t. At most science could say that whatever happened, it was entirely natural. Science may make the resurrection look extremely implausible, but it does not refute it.