David Hume, the Scottish philosopher and historian, was born at
Edinburgh, April 26, 1711, and was educated at the college there.
He tried law and business without liking either, and at the age of
23 went to France, where he wandered about for a while occupied
with dreams of philosophy. In 1739 he published the first part of
his "Treatise on Human Nature." The book set an army of
philosophers at work trying either to refute what he had said or
continue lines that he had suggested, and out of them were created
both the Scotch and German schools of metaphysicians. Hume's
"Essays, Moral and Political," appeared in 1741-42, and followed
closely upon what he described as the "dead-born" "Treatise on
Human Nature," the success of the former going a long way towards
compensating him for the failure of the latter. In the
advertisement to a posthumous edition Hume complains that
controversialists had confined their attacks to the crude, earlier
treatise, and expressed the desire that for the future the "Essays"
might alone be regarded as containing his philosophical sentiments
and principles. In the "Essays" Hume brings to bear the results of
his criticism upon the problems of current speculative discussion.
The argument against miracles is still often discussed; and the
work is well worthy of the author whom many regard as the greatest
thinker of his time. In 1751 he published his "Inquiry Into the
Principles of Morals," which is one of the clearest expositions of
the leading principles of what is termed the utilitarian system.
Hume died on August 25, 1776.
_I.--Doubts Concerning the Understanding_
All the objects of human reason or inquiry may naturally be divided into
two kinds--to wit, _relations of ideas_ and _matters of fact_. Of the
first kind are the sciences of geometry, algebra, and arithmetic, and,
in short, every affirmation which is either intuitively or
demonstratively certain. "That the square of the hypotenuse is equal to
the squares of the two sides" is a proposition which expresses a
relation between these figures. "That three times five is equal to the
half of thirty" expresses a relation between these numbers.
Propositions of this kind are discoverable by the mere operation of
thought, without dependence on what is anywhere existent in the
universe. Though there never were a circle or triangle in nature, the
truths demonstrated by Euclid would for ever retain their certainty and
evidence.
Matters of fact, which are the second objects of human reason, are not
ascertained in the same manner; nor is our evidence of their truth,
however great, of a like nature with the foregoing. The contrary of
every matter of fact is still possible, because it can never imply a
contradiction, and is conceived by the mind with the same facility and
distinctness as if ever so conformable to reality. "That the sun will
not rise to-morrow" is no less intelligible a proposition, and implies
no more contradiction, than the affirmative that "it will rise." We
should in vain, therefore, attempt to demonstrate its falsehood. Were it
demonstratively false, it would imply a contradiction, and could never
be distinctly conceived by the mind.
It may, therefore, be a subject worthy of curiosity to inquire what is
the nature of that evidence which assures us of any real existence of
matters of fact beyond the present testimony of our senses, or the
records of our memory. All reasonings concerning matter of fact seem to
be founded on the relation of _cause_ and _effect_. If we would satisfy
ourselves, therefore, concerning the nature of that evidence which
assures us of matters of fact, we must inquire how we arrive at the
knowledge of cause and effect.
I shall venture to affirm, as a general proposition which admits of no
exception, that the knowledge of this relation is not, in any instance,
attained by reasonings _a priori_, but arises entirely from experience.
To convince us that all the laws of nature, and all the operations of
bodies without exception, are known only by experience, the following
reflections may perhaps suffice. Were any object presented to us, and
were we required to pronounce concerning the effect which will result
from it, without consulting past observation, after what manner, I
beseech you, must the mind proceed in this operation? It must invent or
imagine some event, which it ascribes to the object as its effect; and
it is plain that this invention must be entirely arbitrary. The mind can
never possibly find the effect in the supposed cause by the most
accurate scrutiny and examination. For the effect is totally different
from the cause, and, consequently, can never be discovered in it.
A stone or piece of metal raised into the air and left without any
support immediately falls. But, to consider the matter _a priori_, is
there anything we discover in this situation which can beget the idea of
a downward rather than an upward, or any other motion, in the stone or
metal?
In a word, then, every effect is a distinct event from its cause. It
could not, therefore, be discovered in the cause, and the first
invention or conception of it, _a priori_, must be entirely arbitrary.
And, even after it is suggested, the conjunction of it with the cause
must appear equally arbitrary, since there are always many other effects
which to reason must seem fully as consistent and natural. In vain,
therefore, should we pretend to determine any single event, or infer any
cause or effect, without the assistance of observation and experience.
Hence, we may discover the reason why no philosopher who is rational and
modest has ever pretended to assign the ultimate cause of any natural
operation, or to show distinctly the action of that power which produces
any single effect in the universe.
I say, then, that even after we have experience of the operations of
cause and effect, our conclusions from that experience are _not_ founded
on reasoning, or any process of the understanding.
The bread which I formerly ate nourished me; that is, a body of such
sensible qualities was at that time endued with such secret powers; but
does it follow that other bread must also nourish me at another time,
and that like sensible qualities must always be attended with like
secret powers? The consequence seems nowise necessary. At least, it must
be acknowledged that there is here a consequence drawn by the mind, that
there is a certain step taken; a process of thought, and an inference
which wants to be explained.
These two propositions are far from being the same: "I have found that
such an object has always been attended with such an effect," and: "I
foresee that other objects, which are in appearance similar, will be
attended with similar effects." I shall allow, if you please, that the
one proposition may justly be inferred from the other; I know, in fact,
that it always is inferred. But you must confess that the inference is
not intuitive; neither is it demonstrative. Of what nature is it, then?
To say it is experimental is begging the question. For all inferences
from experience suppose, as their foundation, that the future will
resemble the past, and that similar powers will be conjoined with
similar sensible qualities.
If there be any suspicion that the course of nature may change, and that
the past may be no rule for the future, all experience becomes useless,
and can give rise to no inference or conclusion. It is impossible,
therefore, that any arguments from experience can prove this resemblance
of the past to the future, since all these arguments are founded on the
supposition of that resemblance. Let the course of things be allowed
hitherto ever so regular, that alone, without some new argument or
inference, proves not that for the future it will continue so. In vain
do you pretend to have learned the nature of bodies from your past
experience. Their secret nature, and consequently all their effects and
influence, may change without any change in their sensible qualities.
This happens sometimes, and with regard to some objects. Why may it not
happen always, and with regard to all objects? What logic, what process
of argument, secures you against this supposition? My practice, you say,
refutes my doubts. But you mistake the purport of my question. As an
agent, I am quite satisfied on the point; but as a philosopher, who has
some share of curiosity, I will not say scepticism, I want to learn the
foundation of this inference.
All inferences from experience are effects of custom, not of reasoning.
We have already observed that nature has established connections among
particular ideas, and that no sooner one idea occurs to our thoughts
than it introduces its correlative, and carries our attention towards it
by a gentle and insensible movement. These principles of connection or
association we have reduced to three--namely, _resemblance_,
_contiguity_, and _causation_, which are the only bonds that unite our
thoughts together and beget that regular train of reflection or
discourse which, in a greater or less degree, takes place among mankind.
Now, here arises a question on which the solution of the present
difficulty will depend. Does it happen in all these relations that when
one of the objects is presented to the senses or memory the mind is not
only carried to the conception of the correlative, but reaches a
steadier and stronger conception of it than otherwise it would have been
able to attain? This seems to be the case with that belief which arises
from the relation of cause and effect. And I shall add that it is
conformable to the ordinary wisdom of nature to secure so necessary an
act of the mind by some instinct or mechanical tendency, which may be
infallible in its operations, may discover itself at the first
appearance of life and thought, and may be independent of all the
laboured deductions of the understanding.
_II.--On Miracles_
A wise man proportions his belief to the evidence. In such conclusions
as are founded on an infallible experience he expects the event with the
last degree of assurance, and regards his past experience as a full
_proof_ of the future existence of that event.
In other cases he proceeds with more caution. He weighs the opposite
experiments. He considers which side is supported by the greatest number
of experiments; to that side he inclines with doubt and hesitation, and
when at last he fixes his judgment, the evidence exceeds not what we
properly call _probability_. All probability, then, supposes an
opposition of experiments and observations, where the one side is found
to overbalance the other, and to produce a degree of evidence
proportioned to the superiority.
When the fact attested is such a one as has seldom fallen under our
observation, here is a contest of two possible experiences, of which the
one destroys the other as far as its force goes, and the superior can
only operate on the mind by the force which remains. 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 consideration there necessarily arises a counterpoise, and mutual
destruction of belief and authority.
But in order to increase the probability against the testimony of
witnesses, let us suppose that the fact which they affirm, instead of
being only marvellous, is really miraculous; and suppose also that the
testimony, considered apart and in itself, amounts to an entire proof,
of which the strongest must prevail, but still with a diminution of its
force in proportion to that of its antagonist.
A miracle is a violation of the laws of nature; and as a firm and
unalterable experience has established these laws, the proof against a
miracle, from the very nature of the fact, is as entire as any argument
from experience can possibly be imagined. Why is it more than probable
that all men must die; that lead cannot of itself remain suspended in
the air; that fire consumes wood, and is extinguished by water; unless
it be that these events are found agreeable to the laws of nature, and
there is required a violation of these laws, or, in other words, a
miracle, to prevent them?
Nothing is esteemed a miracle if it ever happen in the common course of
nature. It is no miracle that a man seemingly in good health should die
on a sudden, because such a kind of death, though more unusual than any
other, has yet been frequently observed to happen. But it is a miracle
that a dead man should come to life, because that has never been
observed in any age or country. There must, therefore, be a uniform
experience against every miraculous event, otherwise the event would not
merit that appellation. And as a 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; nor can such a proof be destroyed,
or the miracle rendered credible, but by an opposite proof which is
superior.
The plain consequence is (and it is a general maxim worthy of 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 the superior
only gives us an assurance suitable to that degree of force which
remains after deducting the inferior."
There surely never was a greater number of miracles ascribed to one
person than those which were lately said to have been wrought in France
upon the tomb of Abbe Paris, the famous Jansenist, with whose sanctity
the people were so long deluded. The curing of the sick, giving hearing
to the deaf and sight to the blind, were everywhere talked of as the
usual effects of that holy sepulchre. But, what is more extraordinary,
many of the miracles were immediately proved upon the spot before judges
of unquestioned integrity, attested by witnesses of credit and
distinction, in a learned age, and in the most eminent theatre that is
now in the world.
Nor is this all; a relation of them was published and dispersed
everywhere; nor were the Jesuits--though a learned body, supported by
the civil magistrate and determined enemies to those opinions in whose
favour the miracles were said to have been wrought--ever able distinctly
to refute or detect them. Where shall we find such a number of
circumstances agreeing to the corroboration of one fact? And what have
we to oppose to such a cloud of witnesses but the absolute impossibility
or miraculous nature of the events which they relate? And this surely,
in the eyes of all reasonable people, will alone be regarded as a
sufficient refutation.
Suppose that all the historians who treat of England should agree that
on January 1, 1600, Queen Elizabeth died; that both before and after her
death she was seen by her physicians and the whole court, as is usual
with persons of her rank; that her successor was acknowledged and
proclaimed by the Parliament; and that, after being interred a month,
she again appeared, resumed the throne, and governed England for three
years; I must confess that I should be surprised at the concurrence of
so many odd circumstances, but should not have the least inclination to
believe so miraculous an event. I should not doubt of her pretended
death, and of those other public circumstances that followed it; I
should only assert it to have been pretended, and that it neither was,
nor possibly could be, real.
You would in vain object to me the difficulty and almost impossibility
of deceiving the world in an affair of such consequence; the wisdom and
solid judgment of that renowned queen; with the little or no advantage
which she could reap from so poor an artifice. All this might astonish
me; but I would still reply that the knavery and folly of men are such
common phenomena that I should rather believe the most extraordinary
events to arise from their concurrence than admit of so signal a
violation of the laws of nature.
Our most holy religion is founded on _faith_, not on reason; and it is a
sure method of exposing it to put it to such a trial as it is by no
means fitted to endure. To make this more evident, let us examine those
miracles related in the Pentateuch, which we shall examine as the
production of a mere human writer and historian. Here, then, we are
first to consider a book, presented to us by a barbarous and ignorant
people, written in an age when they were still more barbarous, and in
all probability long after the facts which it relates, corroborated by
no concurring testimony, and resembling those fabulous accounts which
every nation gives of its origin.
Upon reading this book we find it full of prodigies and miracles. It
gives an account of a state of the world and of human nature entirely
different from the present; of our fall from that state; of the age of
man extended to near a thousand years; of the destruction of the world
by a deluge; of the arbitrary choice of one people as the favourites of
Heaven, and that people the countrymen of the author; of their
deliverance from bondage by prodigies the most astonishing imaginable. I
desire anyone to lay his hand upon his heart, and, after a serious
consideration, declare whether he thinks that the falsehood of such a
book, supported by such a testimony, would be more extraordinary and
miraculous than the miracles it relates, which is, however, necessary to
make it be received according to the measures of probability above
established.
_III.--Of a Particular Providence and of a Future State_
I was lately engaged in conversation with a friend who loves sceptical
paradoxes. To my expression of the opinion that a wise magistrate can
justly be jealous of certain tenets of philosophy such as those of
Epicurus, which, denying a divine existence, and consequently a
Providence and a future state, seem to loosen the ties of morality, he
replied as follows.
"If Epicurus had been accused before the people he could easily have
defended his cause and proved his principles of philosophy to be as
salutary as those of his adversaries. And, if you please, I shall
suppose myself Epicurus for a moment, and make you stand for the
Athenian people."
EPICURUS: I come hither, O ye Athenians, to justify in your assembly
what I maintained in my school, and I find myself impeached by furious
antagonists instead of reasoning with calm and dispassionate inquirers.
By my accusers it is acknowledged that the chief or sole argument for a
divine existence (which I never questioned) is derived from the order of
nature; where there appear such marks of intelligence and design that
you think it extravagant to assign for its cause either chance or the
blind and unguided force of matter. You allow that this is an argument
drawn from effects to causes. From the order of the work you infer that
there must have been project and forethought in the workman. If you
cannot make out this point, you allow that your conclusion fails, and
you pretend not to establish the conclusion in a greater latitude than
the phenomena of nature will justify. These are your concessions. I
desire you to mark the consequences.
When we infer any particular cause from an effect we must proportion the
one to the other, and can never be allowed to ascribe to the cause any
qualities but what are sufficient to produce the effect. A body of ten
ounces raised in a scale may serve as a proof that the counterbalancing
weight exceeds ten ounces, but never that it exceeds a hundred.
The same rule holds whether the cause assigned be brute, unconscious
matter or a rational, intelligent being. If the cause be known only by
the effect, we never ought to ascribe to it any qualities beyond what
are precisely requisite to produce the effect. Nor can we return back
from the cause and infer other effects from it beyond those by which
alone it is known to us.
Allowing, therefore, the gods to be the authors of the existence, or
order, of the universe, it follows that they possess that precise degree
of power, intelligence, and benevolence which appears in their
workmanship; but we can never be allowed to mount up from the universe,
the effect, to Jupiter, the cause, and then descend downwards to infer
any new effect from that cause. The knowledge of the cause being derived
solely from the effect, they must be exactly adjusted to each other; and
the one can never refer to anything farther.
I deny a Providence, you say, and Supreme Governor of the world, who
guides the course of events and punishes the vicious with infamy and
disappointment, and rewards the virtuous with honour and success in all
their undertakings. But surely I deny not the course of events itself,
which lies open to everyone's inquiry and examination. I acknowledge
that, in the present order of things, virtue is attended with more peace
of mind than vice, and meets with a more favourable reception from the
world. I am sensible that, according to the past experience of mankind,
friendship is the chief joy of human life, and moderation the only
source of tranquillity and happiness. I never balance between the
virtuous and the vicious life, but am sensible that, to a well-disposed
mind, every advantage is on the side of the former. And what can you say
more, allowing all your suppositions and reasonings?