An Essay Concerning Humane Understanding Volume II Part 26

9. Experience and Testimonies clas.h.i.+ng, infinitely vary the Degrees of Probability.

Thus far the matter goes easy enough. Probability upon such grounds carries so much evidence with it, that it naturally determines the judgment, and leaves us as little liberty to believe or disbelieve, as a demonstration does, whether we will know, or be ignorant. The difficulty is, when testimonies contradict common experience, and the reports of history and witnesses clash with the ordinary course of nature, or with one another; there it is, where diligence, attention, and exactness are required, to form a right judgment, and to proportion the a.s.sent to the different evidence and probability of the thing: which rises and falls, according as those two foundations of credibility, viz. COMMON OBSERVATION IN LIKE CASES, and PARTICULAR TESTIMONIES IN THAT PARTICULAR INSTANCE, favour or contradict it. These are liable to so great variety of contrary observations, circ.u.mstances, reports, different qualifications, tempers, designs, oversights, &c., of the reporters, that it is impossible to reduce to precise rules the various degrees wherein men give their a.s.sent. This only may be said in general, That as the arguments and proofs PRO and CON, upon due examination, nicely weighing every particular circ.u.mstance, shall to any one appear, upon the whole matter, in a greater or less degree to preponderate on either side; so they are fitted to produce in the mind such different entertainments, as we call BELIEF, CONJECTURE, GUESS, DOUBT, WAVERING, DISTRUST, DISBELIEF, &c.

10. Traditional Testimonies, the further removed the less their Proof becomes.

This is what concerns a.s.sent in matters wherein testimony is made use of: concerning which, I think, it may not be amiss to take notice of a rule observed in the law of England; which is, That though the attested copy of a record be good proof, yet the copy of a copy, ever so well attested, and by ever so credible witnesses, will not be admitted as a proof in judicature. This is so generally approved as reasonable, and suited to the wisdom and caution to be used in our inquiry after material truths, that I never yet heard of any one that blamed it.

This practice, if it be allowable in the decisions of right and wrong, carries this observation along with it, viz. THAT ANY TESTIMONY, THE FURTHER OFF IT IS FROM THE ORIGINAL TRUTH, THE LESS FORCE AND PROOF IT HAS. The being and existence of the thing itself, is what I call the original truth. A credible man vouching his knowledge of it is a good proof; but if another equally credible do witness it from his report, the testimony is weaker: and a third that attests the hearsay of an hearsay is yet less considerable. So that in traditional truths, each remove weakens the force of the proof: and the more hands the tradition has successively pa.s.sed through, the less strength and evidence does it receive from them. This I thought necessary to be taken notice of: because I find amongst some men the quite contrary commonly practised, who look on opinions to gain force by growing older; and what a thousand years since would not, to a rational man contemporary with the first voucher, have appeared at all probable, is now urged as certain beyond all question, only because several have since, from him, said it one after another. Upon this ground propositions, evidently false or doubtful enough in their first beginning, come, by an inverted rule of probability, to pa.s.s for authentic truths; and those which found or deserved little credit from the mouths of their first authors, are thought to grow venerable by age, are urged as undeniable.

11. Yet History is of great Use.

I would not be thought here to lessen the credit and use of HISTORY: it is all the light we have in many cases, and we receive from it a great part of the useful truths we have, with a convincing evidence. I think nothing more valuable than the records of antiquity: I wish we had more of them, and more uncorrupted. But this truth itself forces me to say, That no probability can rise higher than its first original. What has no other evidence than the single testimony of one only witness must stand or fall by his only testimony, whether good, bad, or indifferent; and though cited afterwards by hundreds of others, one after another, is so far from receiving any strength thereby, that it is only the weaker.

Pa.s.sion, interest, inadvertency, mistake of his meaning, and a thousand odd reasons, or capricios, men's minds are acted by, (impossible to be discovered,) may make one man quote another man's words or meaning wrong. He that has but ever so little examined the citations of writers, cannot doubt how little credit the quotations deserve, where the originals are wanting; and consequently how much less quotations of quotations can be relied on. This is certain, that what in one age was affirmed upon slight grounds, can never after come to be more valid in future ages by being often repeated. But the further still it is from the original, the less valid it is, and has always less force in the mouth or writing of him that last made use of it than in his from whom he received it.

12. Secondly, In things which Sense cannot discover, a.n.a.logy is the great Rule of Probability.

[SECONDLY], The probabilities we have hitherto mentioned are only such as concern matter of fact, and such things as are capable of observation and testimony. There remains that other sort, concerning which men entertain opinions with variety of a.s.sent, though THE THINGS BE SUCH, THAT FALLING NOT UNDER THE REACH OF OUR SENSES, THEY ARE NOT CAPABLE OF TESTIMONY. Such are, 1. The existence, nature and operations of finite immaterial beings without us; as spirits, angels, devils, &c. Or the existence of material beings which, either for their smallness in themselves or remoteness from us, our senses cannot take notice of--as, whether there be any plants, animals, and intelligent inhabitants in the planets, and other mansions of the vast universe. 2. Concerning the manner of operation in most parts of the works of nature: wherein, though we see the sensible effects, yet their causes are unknown, and we perceive not the ways and manner how they are produced. We see animals are generated, nourished, and move; the loadstone draws iron; and the parts of a candle, successively melting, turn into flame, and give us both light and heat. These and the like effects we see and know: but the causes that operate, and the manner they are produced in, we can only guess and probably conjecture. For these and the like, coming not within the scrutiny of human senses, cannot be examined by them, or be attested by anybody; and therefore can appear more or less probable, only as they more or less agree to truths that are established in our minds, and as they hold proportion to other parts of our knowledge and observation.

a.n.a.lOGY in these matters is the only help we have, and it is from that alone we draw all our grounds of probability. Thus, observing that the bare rubbing of two bodies violently one upon another, produces heat, and very often fire itself, we have reason to think, that what we call HEAT and FIRE consists in a violent agitation of the imperceptible minute parts of the burning matter. Observing likewise that the different refractions of pellucid bodies produce in our eyes the different appearances of several colours; and also, that the different ranging and laying the superficial parts of several bodies, as of velvet, watered silk, &c., does the like, we think it probable that the COLOUR and s.h.i.+ning of bodies is in them nothing but the different arrangement and refraction of their minute and insensible parts. Thus, finding in all parts of the creation, that fall under human observation, that there is A GRADUAL CONNEXION OF ONE WITH ANOTHER, WITHOUT ANY GREAT OR DISCERNIBLE GAPS BETWEEN, IN ALL THAT GREAT VARIETY OF THINGS WE SEE IN THE WORLD, which are so closely linked together, that, in the several ranks of beings, it is not easy to discover the bounds betwixt them; we have reason to be persuaded that, BY SUCH GENTLE STEPS, things ascend upwards in degrees of perfection. It is a hard matter to say where sensible and rational begin, and where insensible and irrational end: and who is there quick-sighted enough to determine precisely which is the lowest species of living things, and which the first of those which have no life? Things, as far as we can observe, lessen and augment, as the quant.i.ty does in a regular cone; where, though there be a manifest odds betwixt the bigness of the diameter at a remote distance, yet the difference between the upper and under, where they touch one another, is hardly discernible. The difference is exceeding great between some men and some animals: but if we will compare the understanding and abilities of some men and some brutes, we shall find so little difference, that it will be hard to say, that that of the man is either clearer or larger.

Observing, I say, such gradual and gentle descents downwards in those parts of the creation that are beneath man, the rule of a.n.a.logy may make it probable, that it is so also in things above us and our observation; and that there are several ranks of intelligent beings, excelling us in several degrees of perfection, ascending upwards towards the infinite perfection of the Creator, by gentle steps and differences, that are every one at no great distance from the next to it. This sort of probability, which is the best conduct of rational experiments, and the rise of hypothesis, has also its use and influence; and a wary reasoning from a.n.a.logy leads us often into the discovery of truths and useful productions, which would otherwise lie concealed.

13. One Case where contrary Experience lessens not the Testimony.

Though the common experience and the ordinary course of things have justly a mighty influence on the minds of men, to make them give or refuse credit to anything proposed to their belief; yet there is one case, wherein the strangeness of the fact lessens not the a.s.sent to a fair testimony given of it. For where such supernatural events are suitable to ends aimed at by Him who has the power to change the course of nature, there, UNDER SUCH CIRc.u.mSTANCES, that may be the fitter to procure belief, by how much the more they are beyond or contrary to ordinary observation. This is the proper case of MIRACLES, which, well attested, do not only find credit themselves, but give it also to other truths, which need such confirmation.

14. The bare Testimony of Divine Revelation is the highest Certainty.

Besides those we have hitherto mentioned, there is one sort of propositions that challenge the highest degree of our a.s.sent, upon bare testimony, whether the thing proposed agree or disagree with common experience, and the ordinary course of things, or no. The reason whereof is, because the testimony is of such an one as cannot deceive nor be deceived: and that is of G.o.d himself. This carries with it an a.s.surance beyond doubt, evidence beyond exception. This is called by a peculiar name, REVELATION, and our a.s.sent to it, FAITH, which [as absolutely determines our minds, and as perfectly excludes all wavering,] as our knowledge itself; and we may as well doubt of our own being, as we can whether any revelation from G.o.d be true. So that faith is a settled and sure principle of a.s.sent and a.s.surance, and leaves no manner of room for doubt or hesitation. ONLY WE MUST BE SURE THAT IT BE A DIVINE REVELATION, AND THAT WE UNDERSTAND IT RIGHT: else we shall expose ourselves to all the extravagancy of enthusiasm, and all the error of wrong principles, if we have faith and a.s.surance in what is not DIVINE revelation. And therefore, in those cases, our a.s.sent can be rationally no higher than the evidence of its being a revelation, and that this is the meaning of the expressions it is delivered in. If the evidence of its being a revelation, or that this is its true sense, be only on probable proofs, our a.s.sent can reach no higher than an a.s.surance or diffidence, arising from the more or less apparent probability of the proofs. But of FAITH, and the precedency it ought to have before other arguments of persuasion, I shall speak more hereafter; where I treat of it as it is ordinarily placed, in contradistinction to reason; though in truth it be nothing else but AN a.s.sENT FOUNDED ON THE HIGHEST REASON.

CHAPTER XVII. OF REASON

1. Various Significations of the word Reason.

THE word REASON in the English language has different significations: sometimes it is taken for true and clear principles: sometimes for clear and fair deductions from those principles: and sometimes for the cause, and particularly the final cause. But the consideration I shall have of it here is in a signification different from all these; and that is, as it stands for a faculty in man, that faculty whereby man is supposed to be distinguished from beasts, and wherein it is evident he much surpa.s.ses them.

2. Wherein Reasoning consists.

If general knowledge, as has been shown, consists in a perception of the agreement or disagreement of our own ideas, and the knowledge of the existence of all things without us (except only of a G.o.d, whose existence every man may certainly know and demonstrate to himself from his own existence), be had only by our senses, what room is there for the exercise of any other faculty, but OUTWARD SENSE and INWARD PERCEPTION? What need is there of REASON? Very much: both for the enlargement of our knowledge, and regulating our a.s.sent. For it hath to do both in knowledge and opinion, and is necessary and a.s.sisting to all our other intellectual faculties, and indeed contains two of them, viz.

SAGACITY and ILLATION. By the one, it finds out; and by the other, it so orders the intermediate ideas as to discover what connexion there is in each link of the chain, whereby the extremes are held together; and thereby, as it were, to draw into view the truth sought for, which is that which we call ILLATION or INFERENCE, and consists in nothing but the perception of the connexion there is between the ideas, in each step of the deduction; whereby the mind comes to see, either the certain agreement or disagreement of any two ideas, as in demonstration, in which it arrives at KNOWLEDGE; or their probable connexion, on which it gives or withholds its a.s.sent, as in OPINION. Sense and intuition reach but a very little way. The greatest part of our knowledge depends upon deductions and intermediate ideas: and in those cases where we are fain to subst.i.tute a.s.sent instead of knowledge, and take propositions for true, without being certain they are so, we have need to find out, examine, and compare the grounds of their probability. In both these cases, the faculty which finds out the means, and rightly applies them, to discover certainty in the one, and probability in the other, is that which we call REASON. For, as reason perceives the necessary and indubitable connexion of all the ideas or proofs one to another, in each step of any demonstration that produces knowledge; so it likewise perceives the probable connexion of all the ideas or proofs one to another, in every step of a discourse, to which it will think a.s.sent due. This is the lowest degree of that which can be truly called reason.

For where the mind does not perceive this probable connexion, where it does not discern whether there be any such connexion or no; there men's opinions are not the product of judgment, or the consequence of reason, but the effects of chance and hazard, of a mind floating at all adventures, without choice and without direction.

3. Reason in its four degrees.

So that we may in REASON consider these FOUR DEGREES: the first and highest is the discovering and finding out of truths; the second, the regular and methodical disposition of them, and laying them in a clear and fit order, to make their connexion and force be plainly and easily perceived; the third is the perceiving their connexion; and the fourth, a making a right conclusion. These several degrees may be observed in any mathematical demonstration; it being one thing to perceive the connexion of each part, as the demonstration is made by another; another to perceive the dependence of the conclusion on all the parts; a third, to make out a demonstration clearly and neatly one's self; and something different from all these, to have first found out these intermediate ideas or proofs by which it is made.

4. Whether Syllogism is the great Instrument of Reason.

There is one thing more which I shall desire to be considered concerning reason; and that is, whether SYLLOGISM, as is generally thought, be the proper instrument of it, and the usefullest way of exercising this faculty. The causes I have to doubt are these:--

First Cause to doubt this.

FIRST, Because syllogism serves our reason but in one only of the forementioned parts of it; and that is, to show the CONNEXION OF THE PROOFS in any one instance, and no more; but in this it is of no great use, since the mind can perceive such connexion, where it really is, as easily, nay, perhaps better, without it.

Men can reason well who cannot make a Syllogism.

If we will observe the actings of our own minds, we shall find that we reason best and clearest, when we only observe the connexion of the proof, without reducing our thoughts to any rule of syllogism. And therefore we may take notice, that there are many men that reason exceeding clear and rightly, who know not how to make a syllogism. He that will look into many parts of Asia and America, will find men reason there perhaps as acutely as himself, who yet never heard of a syllogism, nor can reduce any one argument to those forms: [and I believe scarce any one makes syllogisms in reasoning within himself.] Indeed syllogism is made use of, on occasion, to discover a fallacy hid in a rhetorical flourish, or cunningly wrapt up in a smooth period; and, stripping an absurdity of the cover of wit and good language, show it in its naked deformity. But the mind is not taught to reason by these rules; it has a native faculty to perceive the coherence or incoherence of its ideas, and can range them right without any such perplexing repet.i.tions. Tell a country gentlewoman that the wind is south-west, and the weather lowering, and like to rain, and she will easily understand it is not safe for her to go abroad thin clad in such a day, after a fever: she clearly sees the probable connexion of all these, viz. south-west wind, and clouds, rain, wetting, taking cold, relapse, and danger of death, without tying them together in those artificial and c.u.mbersome fetters of several syllogisms, that clog and hinder the mind, which proceeds from one part to another quicker and clearer without them: and the probability which she easily perceives in things thus in their native state would be quite lost, if this argument were managed learnedly, and proposed in MODE and FIGURE. For it very often confounds the connexion; and, I think, every one will perceive in mathematical demonstrations, that the knowledge gained thereby comes shortest and clearest without syllogism.

Secondly, Because though syllogism serves to show the force or fallacy of an argument, made use of in the usual way of discoursing, BY SUPPLYING THE ABSENT PROPOSITION, and so, setting it before the view in a clear light; yet it no less engages the mind in the perplexity of obscure, equivocal, and fallacious terms, wherewith this artificial way of reasoning always abounds: it being adapted more to the attaining of victory in dispute than the discovery and confirmation of truth in fair enquiries.

5. Syllogism helps little in Demonstration, less in Probability.

But however it be in knowledge, I think I may truly say, it is OF FAR LESS, OR NO USE AT ALL IN PROBABILITIES. For the a.s.sent there being to be determined by the preponderancy, after due weighing of all the proofs, with all circ.u.mstances on both sides, nothing is so unfit to a.s.sist the mind in that as syllogism; which running away with one a.s.sumed probability, or one topical argument, pursues that till it has led the mind quite out of sight of the thing under consideration; and, forcing it upon some remote difficulty, holds it fast there; entangled perhaps, and, as it were, manacled, in the chain of syllogisms, without allowing it the liberty, much less affording it the helps, requisite to show on which side, all things considered, is the greater probability.

6. Serves not to increase our Knowledge, but to fence with the Knowledge we suppose we have.

But let it help us (as perhaps may be said) in convincing men of their errors and mistakes: (and yet I would fain see the man that was forced out of his opinion by dint of syllogism,) yet still it fails our reason in that part, which, if not its highest perfection, is yet certainly its hardest task, and that which we most need its help in; and that is THE FINDING OUT OF PROOFS, AND MAKING NEW DISCOVERIES. The rules of syllogism serve not to furnish the mind with those intermediate ideas that may show the connexion of remote ones. This way of reasoning discovers no new proofs, but is the art of marshalling and ranging the old ones we have already. The forty-seventh proposition of the first book of Euclid is very true; but the discovery of it, I think, not owing to any rules of common logic. A man knows first and then he is able to prove syllogistically. So that syllogism comes after knowledge, and then a man has little or no need of it. But it is chiefly by the finding out those ideas that show the connexion of distant ones, that our stock of knowledge is increased, and that useful arts and sciences are advanced.

Syllogism, at best, is but the art of fencing with the little knowledge we have, without making any addition to it. And if a man should employ his reason all this way, he will not do much otherwise than he who, having got some iron out of the bowels of the earth, should have it beaten up all into swords, and put it into his servants' hands to fence with and bang one another. Had the King of Spain employed the hands of his people, and his Spanish iron so, he had brought to light but little of that treasure that lay so long hid in the dark entrails of America.

And I am apt to think that he who shall employ all the force of his reason only in brandis.h.i.+ng of syllogisms, will discover very little of that ma.s.s of knowledge which lies yet concealed in the secret recesses of nature; and which, I am apt to think, native rustic reason (as it formerly has done) is likelier to open a way to, and add to the common stock of mankind, rather than any scholastic proceeding by the strict rules of MODE and FIGURE.

7. Other Helps to reason than Syllogism should be sought.

I doubt not, nevertheless, but there are ways to be found to a.s.sist our reason in this most useful part; and this the judicious Hooker encourages me to say, who in his Eccl. Pol. 1. i. Section 6, speaks thus: 'If there might be added the right helps of true art and learning, (which helps, I must plainly confess, this age of the world, carrying the name of a learned age, doth neither much know nor generally regard,) there would undoubtedly be almost as much difference in maturity of judgment between men therewith inured, and that which men now are, as between men that are now, and innocents.' I do not pretend to have found or discovered here any of those 'right helps of art,' this great man of deep thought mentions: but that is plain, that syllogism, and the logic now in use, which were as well known in his days, can be none of those he means. It is sufficient for me, if by a Discourse, perhaps something out of the way, I am sure, as to me, wholly new and unborrowed, I shall have given occasion to others to cast about for new discoveries, and to seek in their own thoughts for those right helps of art, which will scarce be found, I fear, by those who servilely confine themselves to the rules and dictates of others. For beaten tracks lead this sort of cattle, (as an observing Roman calls them,) whose thoughts reach only to imitation, NON QUO EUNDUM EST, SED QUO ITUR. But I can be bold to say, that this age is adorned with some men of that strength of judgment and largeness of comprehension, that, if they would employ their thoughts on this subject, could open new and undiscovered ways to the advancement of knowledge.

8. We can reason about Particulars; and the immediate object of all our reasonings is nothing but particular ideas.

Having here had occasion to speak of syllogism in general, and the use of it in reasoning, and the improvement of our knowledge, it is fit, before I leave this subject, to take notice of one manifest mistake in the rules of syllogism: viz. that no syllogistical reasoning can be right and conclusive, but what has at least one GENERAL proposition in it. As if we could not reason, and have knowledge about particulars: whereas, in truth, the matter rightly considered, the immediate object of all our reasoning and knowledge, is nothing but particulars. Every man's reasoning and knowledge is only about the ideas existing in his own mind; which are truly, every one of them, particular existences: and our knowledge and reason about other things, is only as they correspond with those our particular ideas. So that the perception of the agreement or disagreement of our particular ideas, is the whole and utmost of all our knowledge. Universality is but accidental to it, and consists only in this, that the particular ideas about which it is are such as more than one particular, thing can correspond with and be represented by.

But the perception of the agreement or disagreement of our particular ideas, and consequently our knowledge, is equally clear and certain, whether either, or both, or neither of those ideas, be capable of representing more real beings than one, or no.

9. Our Reason often fails us.