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are most languid and confused. Thus memory, in these instances, may be said to correct itself. The case is often much the same with experience and testimony, as will appear more clearly in the second section, where I shall consider the ambiguity of the word experience, as used by this author.

But how, says Mr. Hume, is testimony then to be refuted? Principally in one or other of these two ways: first, and most directly, by contradictory testimony; that is, when an equal or greater number of witnesses, equally or more credible, attest the contrary: secondly, by such evidence either of the incapacity or baseness of the witnesses, as is sufficient to discredit them. What, rejoins my antagonist, cannot then testimony be confuted by the extraordinary nature of the fact attested? Has this consideration no weight at all? That this consideration hath no weight at all, it was never my intention to maintain; that by itself it can very rarely, if ever, amount to a refutation against ample and unexceptionable testimony, I hope to make extremely plain. Who hath ever denied, that the uncommonness of an event related, is a presumption against its reality; and that chiefly on account of the tendency, which, experience teacheth us, and this author hath observed, some people have to sacrifice truth to the love of wonder? The question only is, How far does this presumption extend? In the extent which Mr. Hume hath assigned it, he hath greatly exceeded the limits of nature, and conse quently of all just reasoning.

In his opinion, "When the fact attested is such as has "seldom fallen under our observation, there is a contest of two opposite experiences, of which the one destroys the other, as far as its force goes, and the superiour can only "operate on the mind, by the force which remainst." There is a metaphysical, I had almost said, a magical balance and arithmetick, for the weighing and subtracting of evidence, to which he frequently recurs, and with which he seems to fancy he can perform wonders. I wish he had been a little more explicit in teaching us how these rare inventions must be used. When a writer of genius and elocution expresses himself in general terms, he will find it an easy matter, to give a plausible appearance to things the most unintelligible in nature. Such sometimes is this author's way of writing. In the instance before us he is particularly happy in his choice of metaphors. They are such as are naturally adapted to prepossess a reader in his favour. What candid person can think of suspecting the impartiality of an inquirer, who is for ⚫ p. 184. + p. 179.

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weighing in the scales of reason, all the arguments on either side? Who can suspect his exactness who determines every thing by a numerical computation? Hence it is, that to a superficial view his reasoning appears scarce inferiour to demonstration; but, when narrowly canvassed, it is impracticable to find an application, of which, in a consistency with good sense, it is capable.

In confirmation of the remark just now made, let us try how his manner of arguing on this point can be applied to a particular instance. For this purpose I make the following supposition. I have lived for some years near a ferry. It consists with my knowledge that the passage-boat has a thousand times crossed the river, and as many times returned safe. An unknown man, whom I have just now met, tells me in a serious manner, that it is lost; and affirms, that he himself standing on the bank, was a spectator of the scene; that he saw the passengers carried down the stream, and the boat overwhelmed. No person, who is influenced in his judgment of things, not by philosophical subtilties, but by common sense, a much surer guide, will hesitate to declare, that in such a testimony I have probable evidence of the fact asserted. But if leaving common sense, I shall recur to metaphysicks, and submit to be tutored in my way of judging by the es sayist, he will remind me," that there is here a contest of "two opposite experiences, of which the one destroys the "other, as far as its force goes, and the superiour can only 66 operate on the mind by the force which remains." I am warned, that" the very same principle of experience, which "gives me a certain degree of assurance in the testimony of "the witness gives me also, in this case, another degree of "assurance, against the fact, which he endeavours to estab"lish, from which contradiction there arises a counterpoise "and mutual destruction of belief and authority*."-Well, I would know the truth, if possible; and that I may conclude fairly and philosophically, how must I balance these opposite experiences, as you are pleased to term them? Must I set the thousand, or rather the two thousand instances of the one side, against the single instance of the other? In that case, it is easy to see, I have nineteen hundred and ninetynine degrees of evidence that my information is false. Or, is it necessary, in order to make it credible, that the single instance have two thousand times as much evidence, as any of the opposite instances, supposing them equal among themselves; or supposing them unequal, as much as all the two thousand put together, that there may be at least an

. p. 179.

equilibrium? This is impossible. I had for some of those instances, the evidence of sense, which hardly any testimony can equal, much less exceed. Once more, must the evidence I have of the veracity of the witness, be a full equivalent to the two thousand instances, which oppose the fact attested? By the supposition, I have no positive evidence for or against his veracity, he being a person whom I never saw before. Yet if none of these be the balancing, which the essay-writer means, I despair of being able to discover his meaning.

Is then so weak a proof from testimony incapable of being refuted? I am far from thinking so tho' even so weak a proof could not be overturned by such a contrary experience. How then may it be overturned? First, by contradictory tes timony. Going homewards I meet another person, whom I know as little as I did the former; finding that he comes from the ferry, I ask him concerning the truth of the report. He affirms that the whole is a fiction; that he saw the boat, and all in it, come safe to land. This would do more to turn the scale, than fifty thousand such contrary instances, as were supposed. Yet this would not remove suspicion. Indeed, if we were to consider the matter abstractly, one would think, that all suspicion would be removed, that the two opposite testimonies would destroy each other, and leave the mind entirely under the influence of its former experience, in the same state as if neither testimony had been given. But this is by no means consonant to fact. When once testimonies are introduced, former experience is generally of no account in the reckoning; it is but like the dust of the balance, which hath not any sensible effect upon the scales. The mind hangs in suspence between the two contrary declarations, and considers it as one to one, or equal improbability, that the report is true, or that it is false. Afterwards a third, and a fourth, and a fifth, confirm the declaration of the second. I am then quite at ease. Is this the only effectual way of confuting false testimony? No. I suppose again, that instead of meeting with any person who can inform me concerning the fact, I get from some, who are acquainted with the witness information concerning his character. They tell me, he is notorious for lying; and that his lies are commonly forged, not with a view to interest, but merely to gratify a malicious pleasure, which he takes in alarming strangers. This, though not so direct a refutation as the former, will be sufficient to discredit his report. In the former, where there is testimony contradicting testimony, the author's metaphor of a balance may be used with propriety. The things weighed are homogeneal and when contradictory evidences are presented to the mind, F ff

tending to prove positions which cannot be both true, the mind must decide on the comparative strength of the opposite evidences, before it yield to either.

But is this the case in the supposition first made? By no means. The two thousand instances formerly known, and the single instance attested, as they relate to different facts, though of a contrary nature, are not contradictory. There is no inconsistency in believing both. There is no inconsistency in receiving the last on weaker evidence, (if it be sufficient evidence) not only than all the former together, but even than any of them singly. Will it be said, that though the former instances are not themselves contradictory to the fact recently attested, they lead to a conclusion that is contradictory? I answer, It is true, that the experienced frequency of the conjunction of any two events, leads the mind to infer a similar conjunction in time to come. But let it at the same time be remarked, that no man considers this inference, as having equal evidence with any one of those past events, on which it is founded, and for the belief of which we have had sufficient testimony. Before then the method recommended by this author can turn to any account, it will be necessary for him to compute and determine with precision, how many hundreds, how many thousands, I might say how many myriads of instances, will confer such evidence on the conclusion founded on them, as will prove an equipoise for the testimony of one ocular witness, a man of probity, in a case of which he is allowed to be a competent judge.

There is in arithmetick a rule called REDUCTION, by which numbers of different denominations are brought to the same denomination. If this ingenious author shall invent a rule in logick, analogous to this, for reducing different classes of evidence to the same class, he will bless the world with a most important discovery. Then indeed he will have the honour to establish an everlasting peace in the republick of letters; then we shall have the happiness to see controversy of every kind, theological, historical, philosophical, receive its mortal wound for though, in every question, we could not even then determine with certainty, on which side the truth lay, we could always determine (and that is the utmost the nature of the thing admits) with as much accuracy as geometry and algebra can afford, on which side the probability lay, and in what degree. But till this metaphysical reduction is discovered, it will be impossible where the evidences are of different orders, to ascertain by subtraction the superiour evidence. We could not but esteem him a novice in arithmetick, who being asked, whether seven pounds or eleven pence make

the greater sum, and what is the difference? should, by attending solely to the numbers, and overlooking the value, conclude that eleven pence were the greater, and that it exceeded the other by four. Must we not be equal novices in reasoning, if we follow the same absurd method? Must we not fall into as great blunders? Of as little significancy do we find the balance. Is the value of things heterogeneal to be determined merely by weight? Shall silver be weighed against lead, or copper against iron? If in exchange for a piece of gold, I were offered some counters of baser metal, is it not obvious, that till I know the comparative value of the metals, in vain shall I attempt to find what is equivalent, by the assistance either of scales or arithmetick?

It is an excellent observation, and much to the purpose, which the late learned and pious bishop of Durham, in his admirable performance on the analogy of religion to the course of nature, hath made on this subject. "There is a

❝ man.

very strong presumption," says he, "against the most "ordinary facts, before the proof of them, which yet is over"come by almost any proof. There is a presumption of "millions to one against the story of Cæsar, or of any other For suppose a number of common facts, so and so "circumstanced, of which one had no kind of proof, should "happen to come into one's thoughts every one would, with"out any possible doubt, conclude them to be false. The "like may be said of a single common fact*." What then, I may subjoin, shall be said of an uncommon fact? And that an uncommon fact may be proved by testimony, hath not yet been made a question. But in order to illustrate the observation above cited, suppose, first, one at random mentions, that at such an hour, of such a day, in such a part of the heavens, a comet will appear; the conclusion from experience would not be as millions, but as infinite to one, that the proposition is false. Instead of this, suppose you have the testimony of but one ocular witness, a man of integrity, and skilled in astronomy, that at such an hour, of such a day, in such a part of the heavens, a comet did appear; you will not hesitate one moment to give him credit. Yet all the presumption that was against the truth of the first supposition, though almost as strong evidence as experience can afford, was also against the truth of the second, before it was thus attested.

It is necessary to urge further, in support of this doctrine, that as the water in the canal cannot be made to rise higher than the fountain whence it flows; so it is impossible, that the evidence of testimony, if it proceeded from experience,

Part 2. chap. 2. § 3.

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