This article is an abridged version of the fourth article in a series on philosophy and the paranormal. Here Dr Grey discusses David Hume’s analysis of miracles and his view that belief in miraculous events is always unjustified. He also investigates the nature, virtues and dangers of different skeptical viewpoints.
What is a miracle? In the vernacular we speak of “miraculous” escapes and the like, to characterise events which are extremely unlikely — at odds with the normal course of experience. A miracle in this weak sense just means a very improbable event.
David Hume, in his famous essay “On Miracles”, had a stronger sense of “miracle” in mind, namely something which violates a law of nature. It is in this sense that miracles have commonly featured in religious systems of belief, as the means by which God has been thought to have demonstrated His presence or His power to His chosen people.
The question which Hume addresses is: are we justified in believing that miracles have in fact occurred? He argues for the very strong conclusion that we are never justified in believing that a miracle has ever occurred.
Hume is not claiming to show that miracles have never occurred. Proving negative existence claims is notoriously problematic. Hume’s claim is the importantly different one that we are never rationally justified in believing that miracles have occurred. That is, Hume is addressing the epistemological issue of what it is rational to believe, rather than the metaphysical question of what is and is not possible in our sort of world.
The argument has two parts. First, Hume argues that the evidence against miracles is usually very strong. (And according to one of Hume’s epistemological maxims “a wise man proportions his belief to the evidence.”) We therefore have to weigh the evidence that a miraculous event happened against the evidence that it did not.
In evaluating testimony for miracles, Hume advances the following principle which, echoing the famous methodological principle commonly attributed to William of Ockham (c. 1285-1349), has been called Hume’s Razor. The principle is:
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.
The second stage of the argument claims that even though the evidence in favour of miracles might outweigh the evidence against them, in practice this never happens. Hume maintains that there never was a miraculous event established on sufficiently strong grounds to warrant rational belief in its occurrence. There are four factors which undermine the credibility of any claim in support of the miraculous.
First there is the problem of witness credibility. Witnesses who testify as to the occurrence of miracles are seldom totally above suspicion of either having been deceived or of the intent to deceive. In evaluating their testimony, we must always choose between believing that a miracle occurred or believing that the witnesses were deceived or deceitful.
According to Hume, no miracle has ever been “attested by a sufficient number of men, of such unquestioned good sense, education and learning as to secure us against all delusion in themselves; of such undoubted integrity as to place them beyond all suspicion of any design to deceive others…” All claims for miracles, that is, suffer from what we call a credibility gap.
The second problem which Hume identifies is human credulity. There is a natural human affinity for the novel, the surprising and the marvelous. Recognising this propensity for credulity, we must take note of and be guided by the following maxims in evaluating claims for the miraculous:
- Objects of which we have no experience resemble those of which we do have experience;
- What we have found to be most usual is most probable;
- In case of dispute, give preference to the side favoured by the greatest number of observations.
These sound, if somewhat pedestrian, maxims are frequently overridden by the excitement and novelty which is often the basis of human credulity.
Hume’s third point about miraculous claims is the tribal origins of superstition. Miracles occur mainly in primitive (in Hume’s words “ignorant and barbarous”) nations, or are derived from barbarous and ignorant ancestors. As human understanding develops, we come to reject omens, oracles, astrology, demons, and the like as unhelpful in explaining natural phenomena.
Finally, Hume points to a problem which confronts claims of the miraculous concerning conflicts of testimony. It is impossible that the religious traditions of “ancient Rome, of Turkey, of Siam, and of China” should all of them be established on any solid foundation. Every miracle claimed within any one of these traditions is intended to establish the truth of that tradition and to discredit the claims of the others.
Hume believed that the inclination of mankind towards superstition and the marvelous may receive some check from sense and learning, but he also seems to have believed that it could never be thoroughly extirpated from human nature. Hume, one suspects, would not be surprised to find beliefs in astrology, UFOs, crystals, channeling, and similar credulous ideas in the twentieth century.
The Virtues of Skepticism
Skepticism can be characterised as a critical stance with regard to knowledge (or existence) claims, and a skeptic is one who calls such claims into question. Skepticism can refer to either the critical stance adopted in subjecting knowledge claims to careful scrutiny, or to a state of doubt or disbelief which may be the outcome of such an inquiry.
Being skeptical in the second sense (withholding assent, or suspending belief in a particular claim) need not involve believing the opposite. Skepticism is a matter of doubt rather than denial. If I withhold assent from the claim that God exists, it need not be the case that I believe that God does not exist. I might believe that the evidence is just not strong enough to settle the matter either way.
We need to distinguish between critical and dogmatic skepticism, and between selective and global skepticism, though these terms do not mark absolute distinctions.
Skepticism is dogmatic if assent is withheld a priori, that is, on the basis of prior conviction without considering the evidence. For example, Galileo’s colleagues expressed a perfectly intelligible skepticism about the existence of the moons of Jupiter; they became dogmatic when they refused to look through his telescope.
Skepticism is global if it is general and encompasses all claims to knowledge; selective if it is targeted to specific knowledge claims.
Global skepticism is rare. Perhaps Cratylus, an older contemporary of Plato (c. 428-348 BC), is the most global skeptic recorded in the annals of philosophy. His skepticism is said to have been so extreme that he refused to answer questions and would only wave a weary finger at his interlocutor to indicate that truth was so elusive and ephemeral that it would be useless to reply. (At least, that is what his interlocutors are reputed to have believed him to have been attempting to say).
Skepticism which falls short of the global always has to be qualified by specifying the subject matter to which it is directed. There are various beliefs, for example about rocks and tables, which are immune to skeptical doubts — at least outside philosophy seminar rooms.
At the other extreme there are tooth fairies, Santa Claus and the elixir of life, which most will immediately dismiss as lacking sufficient epistemic warrant. In between (drawing boundaries here will create controversy) there are various disputed cases and claims, such as God, economic rationalism, J-curves, nuclear deterrence and psychic and paranormal phenomena. Disputed cases are also the coal-face of the professional philosopher: on which side of the dividing line, for example, should we put minds, beliefs, desires, meanings, properties, and numbers?
When confronted with a claim about some strange, paranormal or similarly anomalous phenomena (an accurate premonition, a “near death” or an “out of body” experience, say), we should adopt a scrupulously skeptical approach. By this I do not mean that we must conclude that the experience did not occur, or that whoever had the experience must have been somehow deluded — though do not rule that out either! Rather, we should be alert to the possibility of natural and ordinary explanations of unnatural and extraordinary occurrences.
We must be especially careful in evaluating the evidence which appears to support such anomalous events. While rejecting a dogmatic skepticism which refuses to countenance anomalous events, critical skepticism seeks to gather as much evidence as possible concerning any extraordinary or allegedly paranormal event, claim or theory.
Critical skepticism means keeping an open mind not rejecting disputed claims a priori. We must examine the evidence scrupulously. But it means refusing to accept as true claims for which there is insufficient or ambiguous evidence, and recognising that withholding belief is preferable to accepting claims for which there are not sufficient grounds.
It also means adopting as a methodological maxim the principle that in seeking explanations we should prefer the ordinary to the extraordinary, and the simple to the complex. This is one interpretation of the principle known as “Ockham’s Razor”.
Skepticism is the disposition, or art, of matching belief to evidence. There is at present no convenient antonym for “skeptic”. For convenience, I propose to revive the archaic expression “credulist” to serve this role. A credulist can be understood as someone who is apt to accept claims without sufficient evidence, that is to say, someone whose epistemic standards are too low.
Why be Skeptical?
Etymologically, skeptikos means “inquirer”, and the value of skepticism is that it leads to — and when seriously entertained is usually the result of — a systematic inquiry into the foundations of knowledge. Skeptical arguments play a central role in inquiry, particularly philosophical inquiry where they have been directed not just at eccentric belief systems, but at beliefs which most regard as self-evident. Thus skeptical arguments have been raised about the existence of other minds, knowledge of the past, knowledge of material objects (the “external world”), moral truths, sensory knowledge and even about knowledge of logic and mathematics.
The purpose of skepticism in these cases is (usually) not to raise extravagant doubts (though that is sometimes an unintended consequence), but rather to clarify our understanding of the subject of inquiry. There are apparently more modest forms of skepticism which challenge, for example, theological or metaphysical knowledge. And in some cases (for example, I suggest with respect to astrology or phrenology) skepticism seems to be not merely defensible, but appropriate.
When pressed to extremes, skeptical arguments sometimes turn out to be self-defeating, and the critical pursuit of knowledge leads to a denial that knowledge is attainable. Extreme or global skepticism has often been the consequence of setting unreasonably high standards as to what is acceptable as knowledge — in particular setting absolute certainty (the impossibility of being mistaken) as a requirement for genuine knowledge.
Objections to Skepticism
Routine rejoinders to skeptics are, first, the claim that skeptics demand unrealistically high standards of proof (often accompanied by the charge that the skeptics’ insistence on these standards is unjustified), and, second, an insistence (sometimes dogmatic) that a disputed category of experience (a psychic experience, say) is more certain than any skeptical argument which calls them into question.
Regarding the first point, the insistence of protocols, controls, and repeatability are based on the beliefs that nature is consistent — and human nature often suspect. No one demands 100 per cent repeatability. There are always anomalous observations due to the quirks of experimenters or their apparatus. (Indeed with complex scientific experiments it is a formidable task to get anything to work at all.)
But for any extraordinary claim to gain respectability, it has to be replicable by someone somewhere. A recent example of the failure to meet this requirement was the discrediting of the exciting empirical claim by Pons and Fleischmann about so-called cold fusion.
The problem with psi phenomena is not that it is difficult for careful researchers to get it to work occasionally under rigorously controlled conditions; it is difficult for careful observers to get anything at all that can’t be dismissed as noise, error, wishful thinking, chance and often, sadly, fraud. It is for this reason that the requirements of controlled experiments and repeatability cannot be dismissed as unduly fussy: experience shows that nature does not cheat and that people sometimes do.
There are number of manipulative techniques such as “cold reading”, which are well known to psychics (and magicians), which are used to fool people into believing that there are special psychic powers.
Skepticism should not be confused with cynicism, though it frequently is. A cynic is someone who is inclined to believe the worst about people. Cynicism is however a form of skepticism: it is skepticism about the sincerity or goodness of human motives and actions. Historically, Cynics were a sect founded by Antisthenes, a pupil of Socrates, who condemned wealth and the enjoyments of life. The most extreme and celebrated exponent of the movement was Diogenes.
In the history of philosophy we find skeptical arguments are repeatedly proposed and then attacked and “refuted”. Skepticism is a continuing challenge to dogmatic claims, and helps to maintain the spirit of free inquiry. Without skepticism we would be in danger of failing to distinguish enthusiasm, prejudice and superstition from serious, rational, and well-grounded beliefs, which is essential to the task of making sense of the world.
Perhaps the main danger for skeptics is that they sometimes have difficulty in distinguishing hard and soft data, that they set their standards of epistemic acceptability at too high a level (in contrast to credulists, whose epistemic standards are too low) and may tend to promote their own form of dogmatic conservatism.
The aim of skepticism is to combat doctrinal rigidities which can afflict almost any belief system, but skeptics must remain alert to the possibility of falling prey to rigidities of their own. Skepticism is all about matching belief to evidence. It is a difficult and continuing challenge to maintain the right proportion of skepticism in our inquiries. Only then are we able to steer between the Scylla of dogmatism and the Charybdis of credulism.