Think: A Compelling Introduction to Philosophy (25 page)

MIRACLES AND TESTIMONY

Perhaps the core arguments we have looked at fail. But many people suppose that religious faith is well supported by the occurrence
of miraculous events. A prophet may establish divine credentials
by foreseeing the future, or by miraculous healing, or appearance
after death, or other such signs.

Most of us are not directly privileged to see such events. Rather,
we take our belief from other reports of them: testimony. We read
of them in the Bible, or the Koran, or the Lives of the Saints, or even
the National Enquirer. We don't personally watch, for instance, an
amputated limb growing back to normal, but we may have heard
that somewhere over the hills there is an absolutely unshakeable
confirmed sightingof such a thing. People may not personally have
been abducted by aliens, but they may believe wholeheartedly
other people who tell them that they have, or that their brothers or
cousins have. Even if we have not recently sighted the long-buried
Elvis, we may read and believe that some people have.

Hume asked the telling question: when is it reasonable to believe
such testimony?

Suppose we leave on one side the `miraculous' element-the
question of whether any such event is due to invisible powers, or
divine intervention. Still, any candidate for a miracle has to be not
only surprising, but totally surprising, the kind of thing that, in the
normal course of events, just never happens (we are not talking
here about the sense in which the whole creation is miraculous,
since that would take us back to the cosmological argument). To
establish divine credentials, it is not enough for someone to be the
hero of unusual events. He needs really incredible events: people
elevating themselves in the air, lead floating, water turning into
wine, the dead coming back to life. The challenge to the putative
miracle-worker is: go on, amaze me. So when is it reasonable to believe testimony for such outlandish, totally out-of-the-ordinary
events?

Hume begins by making a straightforward enough claim about
human sayings. It is, we believe, a fact that they are mostly true.
Hume claims that if we infer from a premise of the kind `This person is telling me that p' to a conclusion `So, p is probably true', we
are doing the same kind of thing as if we infer from one event, say
`The baseball is flying into the window, to another, `The window
will break.' These inferences are empirical (a posteriori) and are
founded on the way we experience the world to behave. The truthfulness of human testimony is a matter of fact, and founded on experience. And when things go wrong, we do not in fact rely on it.
There can be a `contrariety of evidence', or in other words, some
things pointing one way, and others a different way:

This contrariety of evidence, in the present case, may be derived from several different causes; from the opposition of
contrary testimony; from the character or number of tile witnesses; from the manner of their delivering their testimony; or
from the union of all these circumstances. We entertain a suspicion concerning any matter of fact, when the witnesses contradict each other; when they are but few, or of a doubtful
character; when they have an interest in what they affirm;
when they deliver their testimony with hesitation, or on the
contrary, with too violent asseverations. There are many
other particulars of the same kind, which may diminish orde-
stroy the force of any argument, derived from human testimony.

In other words, experience itself shows us when not to he too
gullible. But now suppose that what is testified to is absolutely
amazing, approaching the miraculous. Then:

The very same principle of experience, which gives us a certain degree of assurance in the testimony of witnesses, gives us
also, in this case, another degree of assurance against the fact,
which they endeavour to establish; from which contradiction
there necessarily arises a counterpoise, and mutual destruction of belief and authority.

Before pausing to analyse the line of thought, we should see where
it leads. Hume draws a famous conclusion:

The plain consequence is (and it is a general maxim worthyof
our attention), That no 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 endeavours to establish; and even in that case there is a mutual
destruction of arguments, and tine superior only gives us an assurance suitable to that degree of force, which remains, after
deducting the inferior.' When any one tells me, that he saw a
dead man restored to life, I immediately consider with myself
whether it be more probable, that this person should either
deceive or be deceived, or that the fact, which he relates,
should really have happened. I weigh the one miracle against
the other; and according to the superiority, which I discover, I
pronounce my decision, and always reject the greater miracle.
If the falsehood of his testimony would be more miraculous,
than the event which he relates; then, and not till then, can he
pretend to command my belief or opinion.

The argument can be analysed in a number of ways. It can usefully
be thought of like this:

Suppose somebody tells me of a highly surprising or improbable event, in. In fact, let in be an event about as improbable as you
can imagine. So my evidence for m is that `this person is saying that
m happened'. I now have a choice between two views of the matter:

(a) This person is saying that in happened. But in did not.

(b) This person is saying that m happened. And m did.

Now each of (a) and (b) contains one surprising element. View (a)
contains the surprise: this person spoke falsely. View (b) contains
the surprise of in occurring. So I have to balance which is more surprising or improbable, and then reject `the greater miracle'.

The problem, as Hume gleefully points out, is that it is quite
common for testimony to be false. There are the obvious cases of
deliberate lies. There are cases of delusions. There are notorious
lapses of memory. Where there is a transmission of information,
errors get introduced: mistranslations, misunderstandings, people taking things intended metaphorically for literal truth, and so on.
So (a) does not involve the same kind of improbability as (b). View
(b) involves the miracle: an event about as improbable as can be
imagined. View (a) only involves the kind of thing that we know
happens anyhow: people get things wrong. Therefore the hurdle
that `no 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 endeavours to establish' is an incredibly difficult hurdle for any piece of testimony to cross. And
even then, all we are left with is a kind of confusion: not knowing
what to believe, so that the wise course is to suspend judgement.

In fact, Hume goes on to argue that no evidence being used to
establish a system of religion ever comes at all close to crossing the
hurdle. He makes a number of points: reports of miracles tend to
come from remote and barbarous times and places; from persons
whose passions are inflamed; from persons who have an interest in
selling a story:

The wise lend a very academic faith to every report which
favours the passion of the reporter; whether it magnifies his
country, his family, or himself or in any other way strikes in
with his natural inclinations and propensities. But what
greater temptation than to appear a missionary, it prophet, an
ambassador from heaven? Who would not encounter many
dangers and difficulties, in order to attain so sublime a character? Or if, by the help of vanity and a heated imagination, a
man has first made it convert of himself, and entered seriously
into the delusion; who ever scruples to make use of pious
frauds, in support of so holy and meritorious a cause?

He points out the way people love such reports:

The passion of surprise and wonder, arising from miracles,
being an agreeable emotion, gives a sensible tendency towards
the belief of those events, from which it is derived. And this
goes so jar, that even those who cannot enjoy this pleasure immediately, nor can believe those miraculous events, of which
they are informed, yet love to partake of the satisfaction at
second-hand or by rebound, and place a pride and delight in
exciting the admiration of others.

With what greediness are the miraculous accounts of travellers received, their descriptions of sea and land monsters,
their relations of wonderful adventures, strange men, and uncouth manners? But if the spirit of religion join itself to the
love of wonder, there is an end of common sense; and human
testimony, in these circumstances, loses all pretensions to authority.

And he makes a more subtle point, concerning the relation
between different religions, each of which has its budget of miracles:

[L]et us consider, that, in matters of religion, whatever is diferent is contrary; and that it is impossible the religions ofan-
cient Rome, of Turkey, of Siam, and of China should, all of
them, be established on any solid foundation. Every miracle,
therefore, pretended to have been wrought in any of these religions (and all of them abound in miracles), as its direct scope
is to establish the particularsystem to which it is attributed; so
has it the same force, though more indirectly, to overthrow
every other system. In destroying a rival system, it likewise
destroys the credit of those miracles, on which that system was
established; so that all the prodigies of different religions are to be regarded as contrary facts, and the evidences of these prodigies, whether weak or strong, as opposite to each other.

This would also be Hume's answer to the protest that so many people cannot be wrong. Whichever way the cake is cut, a huge number of people have to be wrong.

Hume's argument here is wonderfully economical. A less subtle
philosopher might have tried to show a metaphysical conclusion,
such as the absolute impossibility of miracles. Hume neither needs
such a conclusion, nor tries to argue for it. He allows the metaphysical possibility of an intervening deity. There might be a deity
who Wright on occasion let someone walk on water, or feed five
thousand people on a few loaves and fishes. Still, experience is our
only guide as to whether such events occur. If we are to believe that
they do because of testimony, then the testimony has to be good:
very good, and, in fact, miraculously good. But we never find testimony of the right kind.

People new to Hume's argument sometimes suspect that it is
unduly cynical, expressing some kind of mistrustful, suspicious attitude to the reports of other people. I do not think this is true, or
at least, that the suspicion is worse than is warranted by people's
tendencies. After all, you have to be extremely innocent to deny, for
instance, that it is wise to be suspicious of reports that flatter the
passions of the reporter. Here is a quotation from the British newspaper the Independent, commenting on a report by the Royal College of Psychiatrists:

According to the Royal College of Psychiatrists, one in six of us
are neurotic. They must think that ioo per cent of us are gullible as well. Bring out a report-the politically correct
way to advertise your service. What next? The Institute of
Builders says seven in ten houses need to be rebuilt, or the Association of Garage Mechanics that thirteen out of twenty
cars need servicing?

In fact, the discussion in the second part of Hume's great essay is an
ancestor of a whole academic study. Psychologists now investigate
common cognitive malfunctions: failures of perception, of memory, the influences of other people, the infectious qualities of confidence, and the love of the marvellous, as influences that interfere
with people's capacities to tell truth from falsehood. We are mostly
quite good instruments for registering truth and dismissing falsehood. But we are not as good as we like to believe, and we are often
not very good at all.

Hume's argument can elegantly be put in terms of Bayes's theorem, which I explain in the next chapter. The reader may want to
return to this way of putting it after absorbing the explanation
there. In Bayes's terms, we let h be the hypothesis that a miracle occurred, and ebe the fact that some person or persons saythat it occurred. Then the prior probability that the miracle occurred is
very, very small. The `base rate' is near zero. That is because miracles are the kind of thing that either never happen, or almost
never happen. When I leave for the office in the morning, my wife
might warn me against the cold, or the traffic, or my colleagues.
But she doesn't warn me against flying elephants, being taken into
sexual slavery by Martians, or conversations with the living Elvis.
But now consider the fact that someone or some text is saying that
the miracle occurred. Well, this is unhappily very much the kind of thing that happens. The antecedent probability of such evidence
coming into being is never so very small, because there are lots of
other, natural, hypotheses that explain it. These are the common
human frailties: deception, delusion, inflamed passions, mistakes,
and so on. Even the defenders of one favoured set of miracles have
to believe in these frailties, in order to rule out the impostors. The
Roman church has a whole department devoted to unmasking
fake miracles. Christians had better not believe that Muhammad
took his night flight from Mecca to Jerusalem since his credentials
as a miracle-worker contradict those of Jesus. But this means that
the prior probability of e is relatively high. There are many ways in
which `false positives' are generated. Bayes, as we shall see, requires
us to compare these prior probabilities in order to assess how
probable the hypothesis is, given the evidence. The ideal would be
a hypothesis that is not all that improbable, and evidence that cannot easily arise except if the hypothesis is true. But in this kind of
case the prior probabilities are exactly the wrong way round. The
hypothesis is immensely improbable, and the evidence can easily
arise for other reasons. So the Bayesian calculation always conies
down against the truth of the testimony, and in favour of the uniformity of nature.