An Essay Concerning Human Understanding Volume II Part 27

First, In cases when we have no Ideas.

I. It perfectly fails us, where our ideas fail. It neither does nor can extend itself further than they do. And therefore, wherever we have no ideas, our reasoning stops, and we are at an end of our reckoning: and if at any time we reason about words which do not stand for any ideas, it is only about those sounds, and nothing else.

10. Secondly, Because our Ideas are often obscure or imperfect.

II. Our reason is often puzzled and at a loss, because of the obscurity, confusion, or imperfection of the ideas it is employed about; and there we are involved in difficulties and contradictions. Thus, not having any perfect idea of the LEAST EXTENSION OF MATTER, nor of INFINITY, we are at a loss about the divisibility of matter; but having perfect, clear, and distinct ideas of NUMBER, our reason meets with none of those inextricable difficulties in numbers, nor finds itself involved in any contradictions about them. Thus, we having but imperfect ideas of the operations of our minds, and of the beginning of motion, or thought how the mind produces either of them in us, and much imperfecter yet of the operation of G.o.d, run into great difficulties about FREE CREATED AGENTS, which reason cannot well extricate itself out of.

11. III. Thirdly, Because we perceive not intermediate Ideas to show conclusions.

Our reason is often at a stand, because it perceives not those ideas, which could serve to show the certain or probable agreement or disagreement of any other two ideas: and in this some men's faculties far outgo others. Till algebra, that great instrument and instance of human sagacity, was discovered, men with amazement looked on several of the demonstrations of ancient mathematicians, and could scarce forbear to think the finding several of those proofs to be something more than human.

12. IV. Fourthly, Because we often proceed upon wrong Principles.

The mind, by proceeding upon false principles, is often engaged in absurdities and difficulties, brought into straits and contradictions, without knowing how to free itself: and in that case it is in vain to implore the help of reason, unless it be to discover the falsehood and reject the influence of those wrong principles. Reason is so far from clearing the difficulties which the building upon false foundations brings a man into, that if he will pursue it, it entangles him the more, and engages him deeper in perplexities.

13. V. Fifthly, Because we often employ doubtful Terms.

As obscure and imperfect ideas often involve our reason, so, upon the same ground, do dubious words and uncertain signs, often, in discourses and arguings, when not warily attended to, puzzle men's reason, and bring them to a nonplus. But these two latter are our fault, and not the fault of reason. But yet the consequences of them are nevertheless obvious; and the perplexities or errors they fill men's minds with are everywhere observable.

14. Our highest Degree of Knowledge is intuitive, without Reasoning.

Some of the ideas that are in the mind, are so there, that they can be by themselves immediately compared one with another: and in these the mind is able to perceive that they agree or disagree as clearly as that it has them. Thus the mind perceives, that an arch of a circle is less than the whole circle, as clearly as it does the idea of a circle: and this, therefore, as has been said, I call INTUITIVE KNOWLEDGE; which is certain, beyond all doubt, and needs no probation, nor can have any; this being the highest of all human certainty. In this consists the evidence of all those MAXIMS which n.o.body has any doubt about, but every man (does not, as is said, only a.s.sent to, but) KNOWS to be true, as soon as ever they are proposed to his understanding. In the discovery of and a.s.sent to these truths, there is no use of the discursive faculty, NO NEED OF REASONING, but they are known by a superior and higher degree of evidence. And such, if I may guess at things unknown, I am apt to think that angels have now, and the spirits of just men made perfect shall have, in a future state, of thousands of things which now either wholly escape our apprehensions, or which our short-sighted reason having got some faint glimpse of, we, in the dark, grope after.

15. The next is got by Reasoning.

But though we have, here and there, a little of this clear light, some sparks of bright knowledge, yet the greatest part of our ideas are such, that we cannot discern their agreement or disagreement by an immediate comparing them. And in all these we have NEED OF REASONING, and must, by discourse and inference, make our discoveries. Now of these there are two sorts, which I shall take the liberty to mention here again:--

First, through Reasonings that are Demonstrative.

First, Those whose agreement or disagreement, though it cannot be seen by an immediate putting them together, yet may be examined by the intervention of other ideas which can be compared with them. In this case, when the agreement or disagreement of the intermediate idea, on both sides, with those which we would compare, is PLAINLY DISCERNED: there it amounts to DEMONSTRATION whereby knowledge is produced, which, though it be certain, yet it is not so easy, nor altogether so clear as intuitive knowledge. Because in that there is barely one simple intuition, wherein there is no room for any the least mistake or doubt: the truth is seen all perfectly at once. In demonstration, it is true, there is intuition too, but not altogether at once; for there must be a remembrance of the intuition of the agreement of the medium, or intermediate idea, with that we compared it with before, when we compare it with the other: and where there be many mediums, there the danger of the mistake is the greater. For each agreement or disagreement of the ideas must be observed and seen in each step of the whole train, and retained in the memory, just as it is; and the mind must be sure that no part of what is necessary to make up the demonstration is omitted or overlooked. This makes some demonstrations long and perplexed, and too hard for those who have not strength of parts distinctly to perceive, and exactly carry so many particulars orderly in their heads. And even those who are able to master such intricate speculations, are fain sometimes to go over them again, and there is need of more than one review before they can arrive at certainty. But yet where the mind clearly retains the intuition it had of the agreement of any idea with another, and that with a third, and that with a fourth, &c., there the agreement of the first and the fourth is a demonstration, and produces certain knowledge; which may be called RATIONAL KNOWLEDGE, as the other is intuitive.

16. Secondly, to supply the narrowness of Demonstrative and Intuitive Knowledge we have nothing but Judgment upon probable reasoning.

Secondly, There are other ideas, whose agreement or disagreement can no otherwise be judged of but by the intervention of others which have not a certain agreement with the extremes, but an USUAL or LIKELY one: and in these is that the JUDGMENT is properly exercised; which is the acquiescing of the mind, that any ideas do agree, by comparing them with such probable mediums. This, though it never amounts to knowledge, no, not to that which is the lowest degree of it; yet sometimes the intermediate ideas tie the extremes so firmly together, and the probability is so clear and strong, that a.s.sENT as necessarily follows it, as KNOWLEDGE does demonstration. The great excellency and use of the judgment is to observe right, and take a true estimate of the force and weight of each probability; and then casting them up all right together, choose that side which has the overbalance.

17. Intuition, Demonstration, Judgment.

INTUITIVE KNOWLEDGE is the perception of the CERTAIN agreement or disagreement of two ideas immediately compared together.

RATIONAL KNOWLEDGE is the perception of the CERTAIN agreement or disagreement of any two ideas, by the intervention of one or more other ideas.

JUDGMENT is the thinking or taking two ideas to agree or disagree, by the intervention of one or more ideas, whose certain agreement or disagreement with them it does not perceive, but hath observed to be FREQUENT and USUAL.

18. Consequences of Words, and Consequences of Ideas.

Though the deducing one proposition from another, or making inferences in WORDS, be a great part of reason, and that which it is usually employed about; yet the princ.i.p.al act of ratiocination is THE FINDING THE AGREEMENT OR DISAGREEMENT OF TWO IDEAS ONE WITH ANOTHER, BY THE INTERVENTION OF A THIRD. As a man, by a yard, finds two houses to be of the same length, which could not be brought together to measure their equality by juxta-position. Words have their consequences, as the signs of such ideas: and things agree or disagree, as really they are; but we observe it only by our ideas.

19. Four sorts of Arguments.

Before we quit this subject, it may be worth our while a little to reflect on FOUR SORTS OF ARGUMENTS, that men, in their reasonings with others, do ordinarily make use of to prevail on their a.s.sent; or at least so to awe them as to silence their opposition.

First, Argumentum ad verecundiam.

I. The first is, to allege the opinions of men, whose parts, learning, eminency, power, or some other cause has gained a name, and settled their reputation in the common esteem with some kind of authority. When men are established in any kind of dignity, it is thought a breach of modesty for others to derogate any way from it, and question the authority of men who are in possession of it. This is apt to be censured, as carrying with it too much pride, when a man does not readily yield to the determination of approved authors, which is wont to be received with respect and submission by others: and it is looked upon as insolence, for a man to set up and adhere to his own opinion against the current stream of antiquity; or to put it in the balance against that of some learned doctor, or otherwise approved writer. Whoever backs his tenets with such authorities, thinks he ought thereby to carry the cause, and is ready to style it impudence in any one who shall stand out against them. This I think may be called ARGUMENTUM AD VERECUNDIAM.

20. Secondly, Argumentum ad Ignorantiam.

II. Secondly, Another way that men ordinarily use to drive others, and force them to submit their judgments, and receive the opinion in debate, is to require the adversary to admit what they allege as a proof, or to a.s.sign a better. And this I call ARGUMENTUM AD IGNORANTIAM.

21. Thirdly, Argumentum ad hominem.

III. Thirdly, A third way is to press a man with consequences drawn from his own principles or concessions. This is already known under the name of ARGUMENTUM AD HOMINEM.

22. Fourthly, Argumentum ad justicium. The Fourth alone advances us in knowledge and judgment.

IV. The fourth is the using of proofs drawn from any of the foundations of knowledge or probability. This I call ARGUMENTUM AD JUSTICIUM. This alone, of all the four, brings true instruction with it, and advances us in our way to knowledge. For, 1. It argues not another man's opinion to be right, because I, out of respect, or any other consideration but that of conviction, will not contradict him. 2. It proves not another man to be in the right way, nor that I ought to take the same with him, because I know not a better. 3. Nor does it follow that another man is in the right way, because he has shown me that I am in the wrong. I may be modest, and therefore not oppose another man's persuasion: I may be ignorant, and not be able to produce a better: I may be in an error, and another may show me that I am so. This may dispose me, perhaps, for the reception of truth, but helps me not to it: that must come from proofs and arguments, and light arising from the nature of things themselves, and not from my shamefacedness, ignorance, or error.

23. Above, contrary, and according to Reason.

By what has been before said of reason, we may be able to make some guess at the distinction of things, into those that are according to, above, and contrary to reason. 1. ACCORDING TO REASON are such propositions whose truth we can discover by examining and tracing those ideas we have from sensation and reflection; and by natural deduction find to be true or probable. 2. ABOVE REASON are such propositions whose truth or probability we cannot by reason derive from those principles.

3. CONTRARY TO REASON are such propositions as are inconsistent with or irreconcilable to our clear and distinct ideas. Thus the existence of one G.o.d is according to reason; the existence of more than one G.o.d, contrary to reason; the resurrection of the dead, above reason. ABOVE REASON also may be taken in a double sense, viz. either as signifying above probability, or above certainty: and in that large sense also, CONTRARY TO REASON, is, I suppose, sometimes taken.

24. Reason and Faith not opposite, for Faith must be regulated by Reason.

There is another use of the word REASON, wherein it is OPPOSED TO FAITH: which, though it be in itself a very improper way of speaking, yet common use has so authorized it, that it would be folly either to oppose or hope to remedy it. Only I think it may not be amiss to take notice, that, however faith be opposed to reason, faith is nothing but a firm a.s.sent of the mind: which, if it be regulated, as is our duty, cannot be afforded to anything but upon good reason; and so cannot be opposite to it. He that believes without having any reason for believing, may be in love with his own fancies; but neither seeks truth as he ought, nor pays the obedience due to his Maker, who would have him use those discerning faculties he has given him, to keep him out of mistake and error. He that does not this to the best of his power, however he sometimes lights on truth, is in the right but by chance; and I know not whether the luckiness of the accident will excuse the irregularity of his proceeding. This at least is certain, that he must be accountable for whatever mistakes he runs into: whereas he that makes use of the light and faculties G.o.d has given him, and seeks sincerely to discover truth by those helps and abilities he has, may have this satisfaction in doing his duty as a rational creature, that, though he should miss truth, he will not miss the reward of it. For he governs his a.s.sent right, and places it as he should, who, in any case or matter whatsoever, believes or disbelieves according as reason directs him. He that doth otherwise, transgresses against his own light, and misuses those faculties which were given him to no other end, but to search and follow the clearer evidence and greater probability. But since reason and faith are by some men opposed, we will so consider them in the following chapter.

CHAPTER XVIII.

OF FAITH AND REASON, AND THEIR DISTINCT PROVINCES.