In a previous post entitled David Hume’s Distinction between Miracles and Marvels we saw that Hume defined a miracle as a violation of the laws of nature. By this he meant that its occurrence conflicts with the massive body of evidence we have that nature operates in a regular and seamless way, without anomalous exceptions.
I have two hesitations about the tenability of Hume’s definition. First, the term “violation” has a pejorative connotation to it. It suggests that something contrary to nature has occurred; or worse, that an infraction has been committed against nature. Consequently, this definition creates a bias against believing in miracles from the get go, before any arguments have even been considered. In my view, miracles should be defined as charitably as possible for both sides of the discussion. Second, (and related to the first point) it remains to be seen whether a miracle actually conflicts with evidence for the regularities of nature, so we should not assume this view in our definition.
As an alternative to Hume’s definition, I define a miracle as a (1) religiously significant event that is (2) caused by God and (3) exceeds the productive powers of nature. Allow me to clarify these three points:
When an event exceeds the productive powers of nature, I mean that the event is not possible (roughly speaking) when nature is left to its own devices. Philosophers have understood the concept of natural possibility/impossibility in various ways, e.g. in terms of law-like regularities, necessary truths, the casual dispositions of physical objects, or some other theory of natural laws, so when miracles are understood in these ways, several interpretations present themselves: a miracle may be an exception to the general course of nature (the regularity view), a naturally impossible event (the necessity view), or an event that transcends the propensities of physical objects (the dispositions view).
There is still no consensus about how best to understand the concept of natural possibility/impossibility, or how useful the concept of a ‘natural law’ is for articulating it. Therefore, I think it is unwise to hinge my definition of a miracle to a particular theory. The prudent approach, then, is to remain open to the question of how the productive powers of nature would be exceeded, were a miracle to occur.
What about the concept of religiously significance? A miracle is religiously significant if (in addition to being divinely caused and beyond the productive powers of nature) its occurrence serves to corroborate the core message of a person or movement, and to vindicate their actions as having divine authority or approval. The significance of the event would be given by its unique circumstances of the event itself.
For example, if the so-called resurrection of Jesus happened, then it came as the climax of Jesus’ life, teachings, and death by crucifixion. Its occurrence would have corroborated his unique claims to be (among other things) God’s chosen agent for inaugurating the kingdom of God and ushering in a new covenant. It would also have vindicated Jesus’ unprecedented actions of forgiving sins directly, reinterpreting the Mosaic Law by his own authority, and pronouncing judgement on the Jewish Temple system – actions which enraged his opponents and (presumably) got him killed.
Now, perhaps there are other ways to understand the religious significance of miracles in general, or Jesus’ resurrection in particular, but I think my proposal comes close to how we ought to think about it.
What about the divine origin of the event? My definition stipulates that the God of theism is the primary cause of a miracle. Such a being can be minimally described as a benevolent and exceptionally powerful Mind who is responsible for creating the universe. Presumably, this being is capable of much more than causing miracles – e.g. acts of special providence which are nevertheless within the powers of nature of produce – so my definition only focuses on one possible form of divine action in the world.
The advantage of building divine agency into the definition of a miraculous event is that it clarifies (somewhat) the metaphysical assumptions involved in miracle reports – assumptions which are crucial for assessing the prior probability of the event in question. Introducing metaphysics into the definition may appear to be an unnecessary complication, but in my view, attempts to assess a miracle report without considering the prior evidence for and against the existence of God are doomed to failure.
What do you, the reader, think of this definition? Are there any disadvantages which might jeopardize this usefulness?
 The late J.L. Mackie uses similar language to understand laws of nature. He says that laws of nature “describe the ways in which the world – including, of course, human beings – works when left to itself, when not interfered with” (J.L. Mackie, The Miracle of Theism Oxford: Clarendon Press, 1982, pp. 19-20).
 Even this point is debatable because if law-like regularities only tell us how nature works when left to its own devices (see footnote 2), then a miraculous event does not pose an exception. Why? Because nature is not being left to itself when God is causing the event.
 William Craig. Reasonable Faith. Wheaton, IL: Crossway, 1994, p.142-5.
 This point was made apparent to me by Timothy McGrew. He argues that definitions in terms of “the productive powers of nature” accord better with pre-modern views which precede the scientific revolution and therefore make no mention of scientific laws. The views of Thomas Aquinas are a case in point. See McGrew (2011) “Miracles.” Stanford Encyclopaedia of Philosophy. Retrieved on July 20th, 2013, from: http://plato.stanford.edu/entries/miracles/#MirEveExcProPowNat.