Hume's “An Enquiry Concerning Human Understanding” comprises namely of two parts, the first of which delves into the rationale of miracles, where he explores the definitions of a miracle and the standard of evidence necessary to support the claim that such an event has taken place. In the second part, Hume shifts his focus from the abstract to the concrete and argues that, in actuality, no miracles that serve as the foundation for religious systems possess adequate evidence to meet the epistemological criteria laid out in Part I. To assess Hume's success in making a case against miracles, we must primarily consider Part I, the epistemology of miracles. In my view, Hume has convincingly made the argument against miracles while also not ruling out their potentiality, as is expected of a rational thinker.

Hume defines miracles as

“a violation of the laws of nature" where the laws of nature are established from “firm and unalterable experience[s]” (Cahn, 127, Hume). He appears to believe that these “firm and unalterable experience[s]” are established from one’s uniform experiences, that is a consistent set of experiences where nothing has been incorrectly predicted by previous experiences throughout life. Thus since Hume regards that “uniform experience amounts to proof,” we have a full proof for the laws of nature.

Though what does Hume mean by proof? It is important here to explore this as what Hume is referring to as a proof is foundational to the success of his arguments and credibility as a rational actor. Yet given such importance, one would be amiss to find an equally clear definition in his text. However, Hume does distinguish between probability and proof. He defines proofs to be founded on “infallible experience” with which one can expect, with the “last degree of assurance” that their past experiences would constitute a predicted future event and probability to be founded on one’s best judgment of the available evidence. (Hume, 116)

In Earmans’ “Hume's Abject Failure: The Argument Against Miracles,” Earman believes that when Hume refers to proof as being an “infallible experience,” he’s regarding an unfalsifiable metaphysical claim, or in other words, a claim that can not be altered via any evidence. If this were the case, it would make Hume irrational as there would be no evidence that could convince one with such a conviction that they are incorrect. Or as Earman puts it, “[for Hume,] the probability of a miracle is [always] flatly zero. Very simple. And very crude.” (Earman, 23) This could be seen better with Bayesian inferencing, where the probability that a miracle occurred given the evidence is extrapolated as such.

In the case that Hume regarded probability that a miracle occurred to be 0, metaphysically impossible, no evidence could ever change the outcome, the belief. It would always be 0. And the same goes for if is 1, the probability of a miracle occurring is always true and thus, the outcome is also always 1, regardless of any and all evidence to the contrary.

If we take Hume at this level of analysis, his metaphysical argument would boil down to “There must, therefore, be a uniform experience against every miraculous event, otherwise the event would not merit that appellation. And as an uniform experience amounts to a proof, there is here a direct and full proof, from the nature of the fact, against the existence of any miracle[…]”(Cahn, 128, Hume). Essentially stating that since for there to be a miracle, there must definitionally be a uniform experience that amounts to proof against it, and since proofs are binary, miracles always have a probability of 0 and, thus, are never true. No evidence can convince him otherwise. Hume is irrational! But if we merit a better faith analysis, this would not be Hume's argument. He continues the previous statement with “nor can such a proof be destroyed, or the miracle rendered credible, but by an opposite proof, which is superior” (Cahn, 128, Hume). Thus Hume does not believe proofs against a miracle are conferred a binary probability. They can be “rendered credible” by another, better proof. Hume is rational! To disregard this point is to misinterpret Hume altogether, as I believe Earman has done.

With this in mind, we can venture into how Hume presumes one should analyze and compare competing proofs. In Part I, earlier than what is established by Cahn, Hume, an empiricist, explains how one may assume reasoning for such comparisons. Initially, he begins by stating the inherent fallibility of experiential reasoning, “Though experience be our only guide in reasoning concerning matters of fact; it must be acknowledged, that this guide is not altogether infallible, but in some cases is apt to lead us to errors.” In context with the earlier part of this text, It should be evident now that Hume certainly understands the proofs for the laws of nature are not infallible. He continues the above passage with the analogy, “One, who in our climate, should expect better weather in any week of June than in one of December, would reason justly, and conformably to experience; but it is certain that he may happen, in the event, to find himself mistaken.” Thus even when the strongest experiential evidence, uniform experiences (a proof), ties a connection that has correctly predicted all events, Hume understands and argues here that there is no guarantee. P(M) and P(R) can never be 1 or 0.

It is still not clear when Hume compares proofs how he differentiates between that of one's own experiences and that of others. Though It appears most consistent with his arguments that when comparing, the experiences relevant to Hume are not limited to any singular experiential agent but must be that of all experiential agents. There are two primary reasons for this line of reasoning. First, it addresses the issues that arise when reasoning from one's own experience alone, specifically the significant limitation on the matters of fact that one can reason about. For instance, one cannot simply conclude, based on the regularity of their own experience, that a dead man never rises again because nobody has had enough personal experience of death. The second reason for appealing to collective experience arises in cases where an agent reasons, from their uniform experiences, of a consistent correlation of events, that another agent who has also had uniform experiences reasons a consistent uncorrelation of.

Hume's case of the Indian Prince appears to provide the best example of this form of reasoning from collective experience. Upon being informed of the effects frost has on water, freezing it, the Prince reasons from their uniform experience that water is always liquid under all circumstances to the conclusion that the informant must be lying. While the Prince is using reasoning, they arrive at an incorrect conclusion. As Hume points out, such an event [water freezing] may be considered extraordinary and require strong testimony to render it credible to people in a warm climate. However, this event is not miraculous nor contrary to uniform experiences in colder climates where all circumstances are the same. (Hume, 119) This highlights that Hume believes in the importance of considering the experiences of those in different circumstances when evaluating between claims.

Lastly, to assert that Hume rationally addresses all claims for miracles, we must discuss how Hume approaches the testimony of miracles. In Part I, he makes the following famous maxim:

“[N]o testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavors to establish; and even in that case there is a mutual destruction of arguments, and the superior only gives us an assurance suitable to that degree of force, which remains, after deducting the inferior.” (Cahn, 127, Hume)

In which for the testimony of a miracle to be credible Hume is essentially stating that the proof for it must be greater than the proof against it. Then in as so far as the “falsehood [of the testimony] would [have to] be more miraculous, than the fact, which it endeavors to establish,” if the proof for the miracle is already superior to that against it, this would be definitionally true. Essentially testimony is required to be about as perfect as can be to rival the proofs of natural law. A testimony of such stature, Hume asserts, can not be proved “so as to be the foundation of a system of religion” (Cahn, 129, Hume) but does not state that miracles are a priori impossible. When the two rival, we have proof against proof, and Hume states, "[When] there is proof against proof, [..] the strongest must prevail, but still with a diminution of its force, in proportion to that of its antagonist.” (Cahn, 127, Hume)

Hume proceeds with a pragmatic example of someone witnessing the resurrection of a dead man. He evaluates the testimonial proof of the miracle against the experiential proof of the possibility of the witness being deceived and concludes that the greater miracle should be rejected. As we have seen with Hume's observations on the fallibility of our experiences, in most cases, the greater proof will be the fallibility of our experiences rather than the violation of natural law. In other words, the occurrence that does not align with our uniform experience is most often the greater miracle. Thus, Hume has effectively argued for the extreme improbability of a miracle testimony ever being true, but as a rational thinker, has not ruled out the possibility of a miracle ever occurring and its testimony being true.

In his work "On Miracles," Paul Dietl raises an important challenge to Hume's proclivity against the credibility of miracles. Dietl notes that some events which meet the criteria for being considered a miracle may be inherently beyond our ability to analyze or experimentally reproduce. Specifically, Dietl argues that certain miracles may lack an independent variable, making them difficult to understand with scientific analysis. Dietl gives the example of a prophet tasked with performing a miracle under highly controlled conditions where no variable can be “pinned down as the independent variable in scientific explanation.” (Cahn, 132) If the prophet succeeds in accomplishing the miracle, we would be dealing solely with “requests and answers, that is, thoughts, and thoughts not as psychological occurrences but as understood [only from the prophet to a God]. No natural law will do because only vehicles of thought could function as the natural explanans, and no such vehicle is necessary.”

For Dietl's conclusion to hold, he would have to demonstrate that all future scientific inquiries would be categorically unable to provide any natural explanation for the observed phenomenon, not just our current understanding. This is a significant claim and one that Dietl has not successfully justified, as he provides no explanation for how we could rule out all future inquiries. If we encounter a miracle that defies our current scientific understanding and lacks any independent variable to pinpoint, we may still employ Hume's tools to compare the miracles. We could ask ourselves whether it is more miraculous that a God has broken some natural law or simply that we lack the tools of inquiry to analyze the situation.

In essence, Hume's conceptualization of miracles hinges upon the idea of a deviation from the laws of nature as they are established through firm and unalterable experience. Through this framework, he effectively differentiates between probability and proof, the latter of which he defines as being grounded in firm and unalterable experiences that can still be disproven. When the evidential proof for a miracle ever rivals that of natural law, then they must be subjected to a comparative analysis, and the one with greater justification ought to be embraced. However, Hume remains cognizant of the fact that experiences are fallible and that testimony, if of adequate stature, can contest natural laws as proof. In sum, while Hume's perspective successfully discredits the arguments against miracles, his position as a rational thinker precludes him from outrightly disproving their possibility.

Bibliography

Cahn, Steven M. Exploring Philosophy of Religion: An Introductory Anthology. Oxford University Press, 2016.

Earman, John. Hume's Abject Failure: The Argument Against Miracles. Oxford University Press, 2000.

Hume, David. An Enquiry Concerning Human Understanding. The Project Gutenberg, 1748