Wednesday, March 23, 2011

The Possibility of Historical Evidence for Miracles (Part 3)

This post is part of my series on miracles. For an index, see here.

I am currently working my way through the following article:

In this article, Morgan Luck assesses Richard Swinburne’s argument claiming that there can be strong historical evidence for miracles. Luck notes that Swinburne’s argument relies on three key assertions. We have evaluated the first two of these assertions already. Now we turn our attention to the third:

  • Assertion 3: There are conditions under which it is reasonable to assume a violation of a law of nature was caused by God

For the purposes of this evaluation, we are going to assume that we actually do have strong evidence for the occurrence of some kind of miracle. The question we now face is whether we can rightly infer that God is the cause of that miracle.

Swinburne concedes that we would never see God directly causing some miraculous effect. So we would have to make some kind of plausible inference from the effect to the existence of God. He thinks there are two methods for doing this.

1. Argument from Analogy
The first method is to make some kind of analogy between human intentional action and divine intentional action. In other words, we could say that a given miraculous effect seems to be the kind of thing that an agent would bring about (because it is similar to other things that agents like to bring about), but since it involves a violation of a law of nature it cannot be attributed to a human agent; therefore, it must be attributable to a supernatural agent.

To give an example, Swinburne asks us to imagine that 50-foot high fiery lettering appears in the sky reading “I caused these words to appear and I am a rational agent.” He then argues that we would be warranted in inferring that a rational agent caused the lettering to be.

That may be true, but does it warrant us in inferring that God caused it to be? Luck thinks not. He argues that the occurrence of such a violation of a law of nature, that is nonetheless typical of rational agency, is consistent with two other hypotheses: (i) a natural rational agent causing the event by natural means and (ii) a natural rational agent causing the event by means of an intermediary non-natural event.

The first of these hypotheses may elicit a raised eyebrow or two from the reader, but it is perfectly consistent given the definition of a law of nature with which Swinburne is working. As you no doubt recall from part one, for Swinburne a law of nature is a generalised axiom that achieves the best combination of simplicity and strength when applied to the available data.

Under that definition, it is perfectly possible for a natural rational agent to cause a violation of a law of nature by natural means. Presumably, this would just involve the rational agent making use of some as-yet-unknown natural process. Arthur C. Clarke’s famous comment that future technology would be indistinguishable from magic seems apposite here.

So it’s back to the drawing board for Swinburne. On his return, he may stipulate that when making inference to the existence of God, he is assuming that we have evidence that the miraculous event was caused by non-natural means.

One wonders what this evidence would look like, but let’s grant Swinburne the possibility. Even then, Luck argues, he would not be warranted in inferring God. It is, once again, perfectly possible for a natural rational agent to cause the event through a non-natural intermediary process. The possibility being invoked here is logical, not physical or metaphysical, but it is still enough to defeat Swinburne’s argument.

2. The Argument from Prior Belief
Swinburne can bounce back from this defeat. He can argue that we have prior evidence for the existence of God, and that this prior evidence gives us some indication of the kinds of things God would like to bring about. Combining this evidence with the prima facie occurrence of a miracle, might allow us to infer the existence of God.

This is certainly true, but it weakens the apologetic importance of the argument from miracles. No longer are we using the occurrence of a miracle to support the existence of God. Instead, we are using the existence of God to shape our interpretation of a prima facie miracle.

Even if we are willing to tolerate this approach to miracles, problems remain for Swinburne. Two are of particular importance.

First, it is still possible for the event to be attributable to a natural rational agent. Why so? Well, it all comes from the problem of deception. A natural agent, knowing the character of God, could try to mimic him by causing some apparently miraculous effect. (I covered this kind of objection previously in relation to a non-natural event).

Second, go back to part two and look at the discussion of the principle of causal closure (PCC). As noted there, even if we have good prima facie evidence for the occurrence of a miracle, the violation of the PCC makes it virtually impossible to know which particular miracle occurred. This makes it very difficult to know what kind of character is being revealed by a miraculous event.

3. Conclusion
That completes Luck’s evaluation of Swinburne’s case for historical evidence of miracles. We can summarise as follows:

  • Assertion One - "A violation of a law of nature is possible": Luck agrees with this assertion. Adopting Lewis’s Systematic theory, a law of nature is a generalised axiom, from which conclusions about natural events can be deduced, with the best combination of simplicity and strength. It is possible for there to be non-repeatable counter-instances to such laws.
  • Assertion Two - "The existence of particular present events could be indicative of the prior occurrence of particular violations of the laws of nature": Luck objected to this on the grounds that once we allow for the violation of the PCC, evidence can be consistent with any number of miracles.
  • Assertion Three - "There are conditions under which it is reasonable to assume that a violation of a law of nature was caused by God": Luck objects to this on the grounds that it is possible for miracles to be caused by natural rational agents.


  1. The Devil could be a supernatural agent causing a miracle. Like in "The Devil's Lying Wonders" he could deceive us.

  2. Yes, I'm guessing Luck focused on natural agents to make his objection seem even stronger.

  3. I'm having some trouble accepting Luck's acceptance of Assertion One (I know others accept it too). I don't understand why L1 wouldn't just be incorporated. It just seems like granting too much weight to parsimony. What am I missing here?

  4. There tends always to be a tradeoff between the different explanatory virtues when we are trying to assess any particular set of data. In the kinds of case alluded to in the article, accuracy (or comprehensiveness) is being traded off against simplicity.

    You can of course argue that accuracy is more important than simplicity, it's just going to seem, if there is only one known counterinstance to your proposed law or axiom, inelegant.

  5. Yeah, I guess there being only one known counter-instance is really the crux, because in science, this is when people set out to replicate and test and create more instances. It's a temporary situation that's pretty unrealistic really. If having to say that incorporating L1 is as simple as it gets, than that's all we can do.

    IDK, it just seems like parsimony/elegance is too ambiguous of a heuristic to use in such a concrete way. It almost feels like Luck's conceding something just to seem agreeable. Thanks for the reply.

  6. Also, it's not clear that a miracle is actually the more elegant answer anyway, because once you inject (the required parameter of) divine agency into the equation... there's a LOT of inelegance in there.

  7. Ha! Funny how I just came upon this new piece by Massimo P. at the Rationally Speaking blog: "Razoring Ockham’s razor"