The question I want to pose and to which I do not have a firm answer — Nescio ergo blogo! — is whether every case of divine revelation is a miraculous event, or whether there are or can be cases of divine revelation that are not miraculous. To treat this question properly we need some preliminary definitions of key terms. After proposing some definitions I will suggest that they point in the direction of the possibility of non-miraculous revelations.
2. According to a standard way of thinking, miracles are violations of laws of nature. This approach has an impressive pedigree. Thus Thomas Aquinas writes, in the Summa Theologica (Q. 110, art. 4, respondeo), "A miracle properly so called takes place when something is done outside the order of nature." Thomas also alludes (in Reply Obj. 2) to a distinction between miracles ontically and epistemically construed. This is not his terminology. He speaks of miracles "absolutely" considered and miracles "in reference to ourselves." Something that occurs by a power unknown to us may appear miraculous to us and yet not be miraculous absolutely.
A miracle ontically construed is a violation, contravention, "transgression" (Hume's word) of a law of nature. A number of great thinkers have questioned whether there can be miracles in the ontic sense and have proposed epistemic theories of miracles. Augustine is one and Spinoza another:
. . . the universal laws of nature are decrees of God following from the necessity and perfection of the Divine nature. Hence, any event happening in nature which contravened nature's universal laws, would necessarily also contravene the Divine decree, nature, and understanding; or if anyone asserted that God acted in contravention to the laws of nature, he, ipso facto, would be compelled to assert that God acted against His own nature — an evident absurdity. (A Theologico-Political Treatise, tr. Elwes, Dover, p. 83)
It follows from this that miracles are to be construed epistemically:
Further, as nothing happens in nature which does not follow from her laws, and as her laws embrace everything conceived by the Divine intellect, and lastly, as nature preserves a fixed and immutable order; it most clearly follows that miracles are only intelligible as in relation to human opinions, and merely mean events of which the natural cause cannot be explained by a reference to any ordinary occurrence, either by us, or at any rate, by the writer and narrator of the miracle. (p. 84, emphasis added)
In sum, since the course of nature, being ordained by God, cannot be contravened, miracles ontically construed, for Spinoza, are impossible. Talk of miracles, therefore, is simply talk of events we cannot explain. Miracles are thus parasitic upon our ignorance. They are natural events that simply surpass our limited human comprehension. To a perfect understanding nothing would appear miraculous.
3. We now have a tolerably clear idea of what we mean by 'revelation,' 'ontic miracle' and 'epistemic miracle.' Now from the definition of 'revelation' it follows that revelation is something supernatural: its agent is God and God is a supernatural being. But if revelation is supernatural, does it not straightaway follow that revelation is miraculous? Not obviously. It depends on what is meant by 'supernatural.'
The supernatural is that which is above, beyond, or transcendent of nature. Etymology assures us of as much. But what is nature? Nature is the system of space-time-matter. A natural entity is one whose being is exhausted by its occurrence in nature. (One of David Armstrong's immanent universals is therefore a natural entity since its entire being is exhausted by its occurrence in nature; a Platonic unexemplified universal is not a natural entity.) A supernatural entity, then, is one that is either not in nature at all, or, if manifested in nature, not such that its being is exhausted by its manifestation in nature.
Clearly, God (as classically conceived) is not a natural entity by the above definitions. So he is a supernatural entity. But that is not to say that God's existence is ontically miraculous: God's existence does not violate any natural law. Nor is it a law of nature that only nature exists. It is a mistake to confuse the supernatural with the (ontically) miraculous. It is a mistake that Dennett makes.
4. God, a supernatural being, is not a miraculous being. It is not a miracle that God exists since God's existence does not contravene any law of nature. Nor is it obvious that the action of God must be miraculous. God can act on nature without intervening in nature. He could sustain it in being 'vertically' without interfering with any of the causal chains that occur 'horizontally' in nature. So it is false that God's action must involve the violation of natural laws.
5. But if God reveals the Ten Commandments to Moses, say, imparting to his mind the content of the Decalogue, then this is not an acting on nature as a whole, but an imparting of epistemic contents to a mind in nature, the mind of a prophet or mystic. Nevertheless, it is not clear that this need involve the violation of any natural law. A mind in nature need not be a natural entity since a mind in nature need not be an entity whose being is exhausted by its occurrence in nature. Suppose substance dualism is true. Then the creature's mind is a supernatural entity, and it is not clear that a divine supernatural mind communicating with a creaturely supernatural mind need involve any violation of a law of nature.
Another sort of case to be examined is the mental grasping of so-called abstract objects. They are supernatural; but their grasping is presumably non-miraculous.
6. In Exodus 3:2 God gets Moses' attention with a burning bush that is not consumed in its burning. This is a miracle, whether ontic or epistemic. Then in 3:14 God reveals himself to Moses as "I am who am," as Being itself. My point is that this profound revelation needn't be construed as involving any miracle, and could have occurred without the miraculously burning bush. My tentative conclusion, then, is that there are or can be cases of revelation that do not involve violations of laws of nature.