Scottish Philosopher David Hume (1711 – 1776), in his famous “Of Miracles”¹, has argued, “No testimony is sufficient to establish a miracle unless that testimony be of such a kind that its falsehood would be more miraculous than the fact which it endeavours to establish”². Hume then goes on to outline why he believes that no miracle ever has, or ever will have, more evidence supporting it than that opposing it. We first give a brief explanation of Hume’s arguments against the belief in miracles, and then explore whether his arguments apply to paranormal phenomena, discussing the differences between miracles and the paranormal.

First, we must define what Hume meant when he referred to a “miracle”. Hume establishes that a miracle, by its very definition, is an extremely unlikely event, “a transgression of a law of nature [...] by the interposition of some invisible agent”³. A miracle, to Hume at least, is an event that appears to transgress a “law of nature”, where these laws are defined as “conclusions [...] founded on [...] infallible experience”⁴, and caused by the “interposition of some invisible agent”⁵. In other words, a miracle is an event, caused by a god or other such entity, contrary to expected behaviour – an event that appears to be impossible under the established norms of nature, and requires an act of faith to believe.

Hume argues that the logical way to determine the truth between two contradictory situations – in this case, between the occurrence of a miracle, and the non-occurrence of a miracle – is to ascertain which of the events has the more supporting evidence. Hume then states that, as a miracle is essentially an argument against the established norms of nature, there is, by definition, always going to be far greater evidence against the occurrence of a miracle than for it – thus any rational person should, based on the weight of evidence, disbelieve a miracle, and instead believe the event which seems more probable; that we have been deceived, be it by our senses or another, intentionally or not, does not transgress the laws of nature and as such seems more probable than some event that does. Hume goes on to argue four further points against the belief of miracles: that the evidence in support of miracles is further reduced by the believers and witnesses of miracles being both relatively scarce, and frequently unreliable, mistaken or plain fraudulent; that there is a human tendency to irrationally suspend disbelief in the face of “the extraordinary and the marvellous”⁶, especially when there is a religious or faith-based reason for doing so; that many accounts of miracles originated either in the past or in far lands, from where they gained credibility by the passage of time without evidence, or from “barbaric” peoples who, lacking the same rationality we accord ourselves, unquestioningly believe; and finally that, for any miraculous testimony, there are innumerable opposing witnesses.

Having now outlined Hume’s arguments against rational belief in miracles, we explore whether his arguments apply to paranormal phenomena, but first we must define what we mean by “paranormal phenomena”, and how this differs from Hume’s “miracles”. Paranormal literally means “beyond normal”, where normal here refers to the same norms, or laws, of nature Hume’s miracles transgress; therefore, paranormal phenomena are those that exceed the laws of nature, similar to the way in which miracles transgress it, but with the important distinction that a paranormal phenomenon is seen as exceeding accepted natural laws, but not, at least by those that believe it occurred, transgressing it. That is to say, while miraculous events are seen to impossibly transgress some natural law by the miraculous interception of some god, paranormal phenomena, assuming they actually exist, are supposed to be naturally occurring and to fall within the scope of natural laws, but outside our current understanding of those laws; thus, to a believer in the paranormal, paranormal phenomena appear to transgress natural laws, but in fact, do not – instead, they merely exceed our current understanding of natural laws. To a disbeliever in the paranormal, however, paranormal phenomena may appear to be every part as miraculous as a miracle – and here, the only difference we can really deduce between the paranormal and a miracle, is that a miracle is seen to be the direct action of some unseen, and inherently unprovable, deity – requiring faith to believe – while the paranormal is not, being merely scientific – even if currently outside the bounds of known science. Seemingly confusingly, we now have a situation where, to a believer in the paranormal, paranormal phenomena are not actually paranormal, but to those that do not believe in the paranormal, it is no different from the miraculous – but if we consider that those who disbelieve in the paranormal and the miraculous see both as fictitious, and those that purport to believe in them as, at best, deceived, we see that there is actually no confusion.

Now that we have clearly defined paranormal phenomena and considered the differences between it and the miraculous, we can determine the applicability of Hume’s arguments against miracles as applied to paranormal claims. Hume’s foremost argument against miraculous claims – that the evidence against them always outweighs the evidence for them – applies equally well to claims of paranormal phenomena, and for the same reason; by definition, the paranormal exceeds what we consider normal, operating, it is claimed by those who believe the paranormal phenomena, outside known laws of nature; thus, the rational person would need to weigh claims of phenomena purporting to be paranormal against the far greater likelihood of accepted science, claiming such phenomena do not, and cannot, exist. One major difference here is that this argument, when applied against the paranormal, allows for a situation where, some time in the future, scientific knowledge has advanced to such a state that the then currently accepted natural laws allow for what is presently considered paranormal, and which would then be considered simply normal; miracles, however, by definition remain miraculous. To explain this further, were a future change in our understanding – that is, a modification in the accepted natural laws – to lead to a clear understanding of an event previously considered miraculous, then that event never was a miracle; rather, it was merely a mistaken understanding leading to a non-miraculous event being labelled miraculous.

Hume’s argument that those who claim to have witnessed, or hold a belief in, miraculous events are far fewer than those who do not, and are often found to be unreliable, mistaken or fraudulent also applies equally well to those who claim to have witnessed, or believe in, paranormal phenomena; the evidence for an event is clearly lessened if it can be shown that others who make the same claim are frequently proven deceptive or deceived. Another of Hume’s arguments equally applicable to paranormal phenomena as it is the miraculous, is that there is a human tendency to irrationally suspend disbelief in the face of “the extraordinary and the marvellous”⁷, especially when there is a religious or faith-based reason for doing so. It is clear that paranormal phenomena are, or at least can be, every part as extraordinary and marvellous as miraculous events, and are often closely allied with religious or similar faith-based beliefs.

The remaining two arguments Hume presents do not lend themselves as well to claims of the paranormal, as they do claims of the miraculous. Claims of the paranormal are often consistent across cultural, racial and religious divides, so rather than contradictory and opposing witnesses destroying the credit of paranormal claims, consistent witnesses tend to reinforce those claims. Lastly, Hume’s argument that many accounts of miracles originated either from past events or in far lands, gaining credibility without evidence through the passage of time, or through the word of “barbaric” peoples who did not apply the same sceptical and rational thought we expect of ourselves, could be true of claims of paranormal phenomena (as it could be true of anything), but whereas reports of miracles or miraculous beliefs found rooted in past occurrences are seemingly unrepeatable, leaving only myths and rumours, now impossible to test, past paranormal phenomena are claimed to be repeatable, and reoccurring now. This would, we could be forgiven for assuming, mean that those who claim paranormal powers could simply subject themselves or their claims to rigorous scientific examination, and thus the whole issue could be solved for the world to see – but alas, the very nature of the paranormal, by definition, makes it near impossible to conclusively test, hence the continuing controversy.