definition of a miracle in its popular usage is "an event not explicable by natural or scientific laws."
Or is it? Miracles of this kind — the law violating type, are sometimes called Humean miracles, after the 18th century Scottish philosopher David Hume. In Section X in his 1748 book An Enquiry concerning Human Understanding, titled Of Miracles, he defined a miracle as "a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent". Though a source of great debate, this general notion of miracles violating natural law such that they could not happen without the interference of a deity or something outside nature is what we commonly think of when we claim a miracle occurred (despite the fact that colloquially we loosely throw the term around to describe anything unlikely, such as surviving a terrible car crash).
But the Humean definition is only one of many. One of its great rivals is the lesser known Leibnizian miracle, and fits into the view philosopher Kenny Pearce calls Christian naturalism. Leibniz was the 17th/18th century philosopher and mathematician known mostly to apologists as the creator of the argument from contingency. Pearce describes what a miracle is on his blog following Leibniz's insights:
A miracle is an event in which the "higher functions" of the divine consciousness, i.e. the part equivalent to the conscious functioning of the human mind, that makes plans and designs regarding human lives and the like, are more apparent than the "lower functions" which are the laws of nature. To put it more simply (but less precisely) a miracle occurs when the laws of nature conspire together to acheive [sic] some intelligent end. These sorts of miracles are a definite argument not just for the existence of a spiritual being in general, but for the existence of the God of the Judeo-Christian Scriptures.
Um, what? I have to honestly say that I have no idea what he really means in his first sentence. How do the higher functions of the divine consciousness become more apparent than the laws of nature without violating them? It's not clear, especially since earlier in the post Pearce had written:
What I do mean, is the belief that every occurence [sic] in the physical world is governed by a set of fundamental laws to which there are no exceptions.
Except of course that one time, an under-aged virgin girl in Palestine gave birth to a son, who walked on water and turned it into wine without technology, and he died for a few days and came back to life. Yeah, no exceptions. But anyway...
Under Pearce's view, a miracle is not a violation of the laws of nature as they are in Hume's view, but rather a conspiracy within them. The laws of nature allow for a virgin birth, they allow for Moses to part the Red Sea, and they allow for Jesus to rise from the dead. How these things happen within the laws of physics is anyone's guess. It is assumed that our knowledge of natural laws is just incomplete and that further breakthroughs will shed light on the explanations from within nature of how the veridical Christian miracles occurred. That's at least my understanding of Leibnizian miracles.
In addition to this, it is claimed by Leibniz and articulated by Pearce, that for god to violate the laws of physics, it would make him irrational, less than omnibenevolent, and incoherent via descriptivism. In sum, if the laws of physics are regularities, then a law breaking event is unorderly, and if god is perfectly rational, then everything he does is orderly and "for a purpose as part of some greater plan," as Pearce puts it. God having to intervene and violate the regularities of natural law to achieve his "greater plan" would be like a engineer having to constantly fix a machine that he built in order to keep it on course for what it was created for. That wouldn't be compatible with the perfection the biblical deity is supposed to have.
So what do we make of these two opposing views? Do Humean miracles really violate divine benevolence and rationality? And are Leibnizian miracles even coherent with the laws of physics? It's possible for one to view these two opposing views as each cancelling the other out. If one accepts that Humean miracles would be incompatible with divine benevolence and rationality, but also does not see Leibnizian miracles as something coherent with the laws of nature, then one could view each of them as showing the other to be false, in a philosophical double K.O.
How can one show that Leibnizian miracles are incompatible with the laws of nature? Well, if the laws of nature are best described by the laws of physics, then we have good reason not to think any of the reported religious miracles have occurred. The laws of physics governing our everyday experience are well tested and understood. There is no room in them for miracles of the kind Christians, Jews, Muslims, and Hindus believe in. There is no room for a metaphysical object or substance like a soul to have a causal impact on the atoms in your brain or your body, or for your consciousness to leave the body and continue to go on existing apart from it or any physical medium. The "conscious functioning of the human mind, that makes plans and designs regarding human lives and the like" that Pearce mentions are all caused by the atoms in the brain which are all governed by the laws of physics. There is no room for the Earth to stop spinning so that someone can finish a battle, or for a prophet to turn water into wine, or for anyone to move an object with their mind. The standard model of physics and quantum field theory simply don't allow it.
But of course many theists will simply never accept this and will try to argue that the laws of physics are currently incomplete or will always be incomplete, such that we'll never be able to rule out Leibnizian miracles — in effect, making their position unfalsifiable. Or, they'll try to argue for the Humean law breaking miracles, which are apparently incoherent according to Leibniz and Pearce. They can never accept the idea of science ruling out things required by their religion. But some theists, however, will change their mind upon this evidence and that gives atheists like me hope that evidence can change minds. And so, this conflict in miracle kinds actually offers the atheist an argument against miracles in general, as Pearce acknowledges, "If Leibniz's arguments succeed but his account of miracles fails, then he has gotten traditional religious belief into some trouble."
See also Pearce's PDF A Leibnizian Theory of Miracles