Manuscript material from:
Charles Peirce's Projected "Logic of 1873"

Fragments in Collected Papers 7, dated 1872-73

        According to the editors of the Collected Papers, the various document fragments collected in the present composite document are all dated 1872 or 1873 or circa 1873 (CP 7.313-361). In a letter to his brother Henry dated November 24, 1872, William James says, "Charles Peirce . . . read us an admirable introductory chapter to his book on logic the other day" (Perry's biography of William James, vol. 1, 332). IT is obvious that this is draft material for the first two essays in the Illustrations of the Logic of Science series of 1877-78, which appeared in Popular Science Monthly—namely "The Fixation of Belief" (1877) and "How to Make Our Ideas Clear" (1878), and there are a number of passages which appear verbatim or nearly so in one or the other of them—which are actually two parts of a single paper and are treated that way by Peirce later, in 1910, when he worked on a revision of the two of them regarded as one.
         On page 1 of the draft, in a preface for this later revised version, Peirce says: "The main part of this Essay—the characterizations of Belief and of Doubt, the argument as to the effective aim of inquiry, the description of four methods directed toward that aim, with the criticisms of them, the discussion of the proper function of thinking, and the consequent maxim for attaining clear concepts—reproduces almost verbatim a paper I read—it must have been in 1872—to a group of young men who used, at that time, to meet once a fortnight in Cambridge, Mass., under the name of 'The Metaphysical Club—a name chosen to alienate such as it would alienate." (This MS page is headed "1909 Apr 6 2AM, MEANING, Pragmatism." Cf. 5.13 and [Bibliography] G-1909-1.)

The very first of distinctions which logic supposes is between doubt and belief, a question and a proposition. Doubt and belief are two states of mind which feel different, so that we can distinguish them by immediate sensation. We almost always know without any experiment when we are in doubt and when we are convinced. This is such a difference as there is between red and blue, or pleasure and pain. Were this the whole distinction, it would be almost without significance. But in point of fact the mere sensible distinguishability is attended with an important practical difference. When we believe, there is a proposition which according to some rule determines our actions, so that our belief being known, the way in which we shall behave may be surely deduced, but in the case of doubt we have such a proposition more or less distinctly in our minds but do not act from it. There is something further removed from belief than doubt, that is to say not to conceive the proposition at all. Nor is doubt wholly without effect upon our conduct. It makes us waver. Conviction determines us to act in a particular way while pure unconscious ignorance alone which is the true contrary of belief has no effect at all. [CP 7.313]

        Belief and doubt may be conceived to be distinguished only in degree. [CP 7.314]
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        The characters of belief are three. First, there is a certain feeling with regard to a proposition. Second, there is a disposition to be satisfied with the proposition. And third, there is a clear impulse to act in certain ways, in consequence. [CP 7.313n3]
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        Doubt has degrees and may approximate indefinitely to belief, but when I doubt, the effect of the mental judgment will not be seen in my conduct as invariably or to the full extent that it will when I believe. Thus, if I am perfectly confident that an insurance company will fulfill their engagements I will pay them a certain sum for a policy, but if I think there is a risk of their breaking, I shall not pay them so much. [CP 7.314n4]
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        Living doubt is the life of investigation. When doubt is set at rest inquiry must stop. . . . [CP 7.315] [According to the editors of the Collected Papers, in the omitted portion of the manuscript Peirce briefly outlines three of his four "methods of effecting a settlement of opinion." The first is "obstinate adhering to whatever happens to be one's existing opinions." The second is by persecution. The third is "by the natural development of opinion," which fails when "one community comes in contact with another. Then it is seen that the result is quite accidental and dependent on surrounding circumstances and initial conditions and belief gets all unsettled. In this way once more the conviction is forced on man that another's opinion, if derived by the same process as his own, is as good as his own, and that other's opinion is taken by him for his own. Then he says we in the sense of the learned world."] [CP 7.315n5]
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        From this conception springs the desire to get a settlement of opinion [that] is some conclusion which shall be independent of all individual limitations, independent of caprice, of tyranny, of accidents of situation . . . .—a conclusion to which every man would come who should pursue the same method and push it far enough. The effort to produce such a settlement of opinion is called investigation. Logic is the science which teaches whether such effforts are rightly directed or not. [CP 7.316]
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        There is an important difference between the settlement of opinion which results from investigation and every other such settlement. It is that investigation will not fix one answer to a question as well as another, but on the contrary it tends to unsettle opinions at first, to change them and to confirm a certain opinion which depends only on the nature of investigation itself. The method of producing fixity of belief by adhering obstinately to one's belief, tends only to fix such opinions as each man already holds. The method of persecution tends only to spread the opinions which happen to be approved by rulers; and except so far as rulers are likely to adopt views of a certain cast does not determine at all what opinions shall become settled. The method of public opinion tends to develop a particular body of doctrine in every community. Some more widely spread and deeply rooted conviction will gradually drive out the opposing opinions, becoming itself in the strife somewhat modified by these. But different communities, removed from mutual influence, will develop very different bodies of doctrine, and in the same community there will be a constant tendency to sporting which may at any time carry the whole public. What we know of growth, in general, shows that this will take place; and history confirms us. The early history of sciences before they begin to be really investigated, especially of psychology, metaphysics, etc., illustrates as well as anything the pure effect of this method of fixing opinions. The numerous well-defined species of doctrines which have existed on such subjects and their progressive historical succession give the science of the history of philosophy considerable resemblance to that of paleontology. [CP 7.317]

        Thus no one of these methods can as a matter of fact attain its end of settling opinions. Men's opinions will act upon one another and the method of obstinacy will infallibly be succeeded by the method of persecution and this will yield in time to the method of public opinion and this produces no stable result. [CP 7.318]

        Investigation differs entirely from these methods in that the nature of the final conclusion to which it leads is in every case destined from the beginning, without reference to the initial state of belief. Let any two minds investigate any question independently and if they carry the process far enough they will come to an agreement which no further investigation will disturb. [CP 7.319]

        But this will not be true for any process which anybody may choose to call investigation, but only for investigation which is made in accordance with appropriate rules. Here, therefore, we find there is a distinction between good and bad investigation. This distinction is the subject of study in logic. Some persons will doubt whether any sort of investigation will settle all questions. I refrain, however, from arguing the matter, because I should thus be led to anticipate what comes later, and because after any demonstration I might give I should still rest on some assumption and it is as easy to see that investigation assumes its own success as that it assumes anything else. [CP 7.320]

        Logic is the doctrine of truth, its nature and the manner in which it is to be discovered. [CP 7.321]

        The first condition of learning is to know that we are ignorant. A man begins to inquire and to reason with himself as soon as he really questions anything and when he is convinced he reasons no more. Elementary geometry produces formal proofs of propositions which nobody doubts, but that cannot properly be called reasoning which does not carry us from the known to the unknown, and the only value in the first demonstrations of geometry is that they exhibit the dependence of certain theorems on certain axioms, a thing which is not clear without the demonstrations. When two men discuss a question, each first endeavors to raise a doubt in the mind of the other, and that is often half the battle. When the doubt ceases there is no use in further discussion. Thus real inquiry begins when genuine doubt begins and ends when this doubt ends. And the premises of the reasoning are facts not doubted. It is therefore idle to tell a man to begin by doubting familiar beliefs, unless you say something which shall cause him really to doubt them. Again, it is false to say that reasoning must rest either on first principles or on ultimate facts. For we cannot go behind what we are unable to doubt, but it would be unphilosophical to suppose that any particular fact will never be brought into doubt. [CP 7.322]

        It is easy to see what truth would be for a mind which could not doubt. That mind could not regard anything as possible except what it believed in. By all existing things it would mean only what it thought existed, and everything else would be what it would mean by nonexistent. It would, therefore, be omniscient in its universe. To say that an omniscient being is necessarily destitute of the faculty of reason, sounds paradoxical; yet if the act of reasoning must be directed to an end, when that end is attained the act naturally becomes impossible. [CP 7.323]

        The only justification for reasoning is that it settles doubts, and when doubt finally ceases, no matter how, the end of reasoning is attained. Let a man resolve never to change his existing opinions, let him obstinately shut his eyes to all evidence against them, and if his will is strong enough so that he actually does not waver in his faith, he has no motive for reasoning at all, and it would be absurd for him to do it. That is method number one for attaining the end of reasoning, and it is a method which has been much practised and highly approved, especially by people whose experience has been that reasoning only leads from doubt to doubt. There is no valid objection to this procedure if it only succeeds. It is true, it is utterly irrational; that is to say it is foolish from the point of view of those who do reason. But to assume that point of view is to beg the question. In fact, however, it does not succeed; and the first cause of failure is that different people have different opinions and the man who sees this begins to feel uncertain. It is therefore desirable to produce unanimity of opinion and this gives rise to method number two, which is to force people by fire and sword to adopt one belief, to massacre all who dissent from it and burn their books. This way of bringing about a catholic consent has proved highly successful for centuries in some cases, but it is not practicable in our days. A modification of this is method number three, to cultivate a public opinion by oratory and preaching and by fostering certain sentiments and passions in the minds of the young. This method is the most generally successful in our day. The fourth and last method is that of reasoning. It will never be adopted when any of the others will succeed and it has itself been successful only in certain spheres of thought. Nevertheless those who reason think that it must be successful in the end, and so it would if all men could reason. There is this to be said in favor of it. He who reasons will regard the opinions of the majority of mankind with contemptuous indifference; they will not in the least disturb his opinions. He will also neglect the beliefs of those who are not informed, and among the small residue he may fairly expect some unanimity on many questions. [CP 7.324]

        I hope it will now be plain to the reader, that the only rational ground for preferring the method of reasoning to the other methods is that it fixes belief more surely. A man who proposes to adopt the first method may consistently do so simply because he chooses to do so. But if we are to decide in favor of reasoning, we ought to do so on rational grounds. Now if belief is fixed, no matter how, doubt has as a matter of fact ceased, and there is no motive, rational or other, for reasoning any more. Any settlement of opinion, therefore, if it is full and perfect, is entirely satisfactory and nothing could be better. It is the peculiarity of the method of reasoning, that if a man thinks that it will not burn him to put his hand in the fire, reasoning will not confirm that belief but will change it. This is a vast advantage to the mind of a rationalist. But the advocate of any one of the first three methods, will be able to say (if either of these methods will yield a fixed belief) either that he knows by his method that fire will burn, so that reasoning is inferior to his method in that it may permit a man for a moment to doubt this, or else that he knows that fire will not burn, so that reasoning leads all astray. In either case therefore he will conceive that which to the rationalist seems the great advantage of reasoning, to be a great fault. Thus the only ground of a fair decision between the methods must be that one actually succeeds while the others break up and dissolve. Pope expresses the philosophy of the matter perfectly: [CP 7.325]

                Truth struck to earth shall rise again
                The eternal years of God are hers
                While error . . . writhes in pain
                And dies amidst her worshippers.
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        It is the business of the logician to study the nature of the fourth method of inquiry and to discover the rules for conducting it with success. The whole subject will in the exposition of it here offered to the reader be divided into three parts. The first shall treat of the essence of investigation in general, by whatever mind it is conducted and to whatever subject it is applied. The second shall treat of those maxims of investigation which become necessary owing to the peculiar constitution of man in his senses, and his mental nature. The third shall give some slight outline of the special methods of research which are applicable in the different branches of science, and which arise from the peculiarities of the matter investigated. In this first part then we have, broadly speaking, nothing to do with the nature of the human mind. Only as there are some faculties which must belong to any mind which can investigate at all, these must come under our consideration. All inquiry, for example, presupposes a passage from a state of doubt to a state of belief; and therefore there must be a succession of time in the thoughts of any mind which is able to inquire. In the fourth method of inquiry a certain predetermined though not pre-known belief is sure to result from the process; no matter what may have been the opinion of the inquirer at the outset. It follows that during the investigation elements of thought must have sprung up in the mind which were not caused by any thought which was present at the time the investigation was commenced. Such new ideas springing up in the mind and not produced by anything in the mind, are called sensations. Every mind capable of investigation must therefore have a capacity for sensations. But were all thoughts of this kind investigation would be almost an involuntary process. We might will to investigate but we could not change the course which investigation should take. There would therefore be no distinction between a right and a wrong method of investigation. Now we have seen in the last chapter, that such a distinction is essential to the fourth method of inquiry and is, in fact, the only thing which distinguishes it from the third. There must be thoughts therefore which are determined by previous thoughts. And such a faculty of producing thoughts from others must belong to every mind which can investigate. Without a succession of ideas in time it is clear that no reasoning is possible. I shall proceed to show that without it and without the determination of one idea by another no thought in any proper sense of the word is possible. [CP 7.326]
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        Because the only purpose of inquiry is the settlement of opinion, we have seen that everyone who investigates, that is, pursues an inquiry by the fourth method assumes that that process will, if carried far enough, lead him to a certain conclusion, he knows not what beforehand, but which no further investigation will change. No matter what his opinion at the outset may be, it is assumed that he will end in one predestinated belief. Hence it appears that in the process of investigation wholly new ideas and elements of belief must spring up in the mind which were not there before. [CP 7.327]

        Some thoughts are produced by previous thoughts according to regular laws of association, so that if the previous thoughts be known, and the rule of association be given, the thought which is so produced may be predicted. This is the elaborative operation of thought, or thinking par excellence. But when an idea comes up in the mind which has no such relation to former ideas, but is something new to us, we say that it is caused by something out of the mind, and we call the process by which such thoughts spring up, sensation. And those parts of investigation which consist chiefly in supplying such materials for thought to work over, combine and analyze, are termed observations. The first thing to be noted then is that since investigation leads us from whatever state of opinion we may happen to have to an opinion which is predetermined, it must be that investigation involves observation as one part of it, and, in fact, the conclusion to which we finally come ultimately depends entirely upon the observations. [CP 7.328]

        We may pause here to make a practical application of this principle. No argument can possibly be a correct one which pretends to disclose to us a fact wholly new without being based on evidence which is new. The metaphysicians are given to this kind of reasoning; even those of them who are the most energetic in maintaining that all our knowledge comes from sense. Writers upon the nature of the human mind, especially, have built up a great body of doctrine without the aid of any observations or facts, except such as are familiar to all the world. Such things justly excite our suspicion. When Hobbes, for example, would persuade us that no man can act otherwise than for the sake of pleasure, it is clear that this belief would deeply modify our conceptions of men, and our plans of life; but when on asking what supports this momentous conclusion we learn that it is but the simple fact -- if it can be dignified by that name -- that every man desires to do what he does do, we are led at once to suspect that there is some sophistry in the process by which so novel a conclusion can be drawn from so familiar a premise. So, when modern necessitarians maintain that every act of the will proceeds from the strongest motive, they lay down a principle which should be expected to give rise to a psychological science as exact as mechanics, and capable of reducing human actions to precise calculation. But when we find that the advocates of this principle have made no experiments to test their law, we are strongly inclined to think that there has been some juggle of reasoning which has enabled them thus to create something out of nothing. [CP 7.329]

        An observation, as we have defined it, is merely an idea arising in the mind, and not produced by previous ideas. This is not the complete description of observation as understood by scientific men, and we must be careful that the word does not lead us to conclusions which we are not yet warranted in drawing. For example a dream, a presentiment or some fancied inspiration from on high, might, as far as we have yet seen, involve entirely new elements of thought, and, therefore, be an observation in the sense of our definition, so that we are not yet warranted in saying that such things cannot be the ground of legitimate reasoning. This is a question which we shall have again to examine when we come to consider those maxims of inference which depend upon the peculiar constitution of man. [CP 7.330]

        But Observation alone cannot constitute investigation; for if it did the only active part which we should have to play in this method of inquiry would be simply the willing to observe, and there would be no distinction of a wrong method and a right method of investigation. But we have seen that such a distinction is essential to the idea of investigation, and that it is, in fact the only thing which separates this from the third method of inquiry. Accordingly, besides observation it must be that there is also an elaborative process of thought by which the ideas given by observation produce others in the mind. [Footnote by Peirce to the effect that investigation involves, besides sensation, "the production of new beliefs out of old ones according to logical laws. This process is the logical process, but by an extension of the meaning of a familiar word I call it also inference."] Besides, the observations are most varied and are never exactly repeated or reproduced so that they cannot constitute that settled opinion to which investigation leads. Two men, for example, agree in an opinion, and if you ask upon what their opinions rest they will perhaps allege the same fact. But trace the matter back further; ask them upon what grounds they believe that fact again and you will eventually come to premises that are different. Two minds, for example, may have formed the same judgment of a certain person's character and yet may have based their opinions on observing his behavior on different occasions. The rotation of the earth was at first inferred from the movement of the heavenly bodies; but afterwards the manner in which a long pendulum when allowed to swing would gradually turn around and change its direction of oscillation, afforded an entirely new proof; and there are certain very small movements of the stars, which, if they were capable of sufficiently exact observation, would show another ground for the same conclusion. Indeed, the fact which one man observes, is in no case precisely the same as the fact which another man observes. One astronomer observes that the moon passes over a star so as to hide it at a certain instant at his observatory, another astronomer observes that the same star is occulted at a certain instant at his observatory. These two facts are not the same, because they relate to different stations of observation. What is so plain in regard to astronomical observation, because we are accustomed to precision of thought about this, is equally true in regard to the most familiar facts. You and I both see an ink-stand on the table; but what you observe, is that there is a certain appearance from where you sit, and what I observe, is that there is a certain appearance from where I sit. The fact in which we agree, that there is an ink-stand there, is what we conclude from the different appearances which we each severally observe. We may change places and still we shall fail to get each other's observations; for the difference of time then comes in. I may observe that there is such an appearance now as you describe as having existed a few moments before; but I cannot observe that there was such an appearance before I took your place. It is needless to multiply these examples, because the slightest reflection will supply them in any number; but what have been adduced are sufficient to show that observations are for every man wholly private and peculiar. And not only can no man make another man's observations, or reproduce them; but he cannot even make at one time those observations which he himself made at another time. They belong to the particular situation of the observer, and the particular instant of time. [CP 7.331]

        Indeed, if we carefully distinguish that which is first given by sensation, from the conclusion which we immediately draw from it, it is not difficult to see that different observations are not in themselves even so much as alike; for what does the resemblance between the two observations consist in? What does it mean to say that two thoughts are alike? It can only mean that any mind that should compare them together, would pronounce them to be alike. But that comparison would be an act of thought not included in the two observations severally; for the two observations existing at different times, perhaps in different minds, cannot be brought together to be compared directly in themselves, but only by the aid of the memory, or some other process which makes a thought out of previous thoughts, and which is, therefore, not observation. Since, therefore, the likeness of these thoughts consists entirely in the result of comparison, and comparison is not observation, it follows that observations are not alike except so far as there is a possibility of some mental process besides observation. [CP 7.332]

        Without however insisting upon this point which may be found too subtile, the fact remains that the observations are not the same in the sense in which the conclusions to which they give rise are the same. All astronomers, for example, will agree that the earth is ninety-two or ninety-three millions of miles from the sun. And yet, one would base his conclusion on observations of the passage of Venus across the sun's disk; another upon observations of the planet Mars; another upon experiments upon light combined with observations of the satellites of Jupiter. And the same thing is equally true in regard to most of the ordinary affairs of life. [CP 7.333]

        Now how is it that the springing up into the mind of thoughts so dissimilar should lead us inevitably though sometimes not until after a long time to one fixed conclusion? Disputes undoubtedly occur among those who pursue a proper method of investigation. But these disputes come to an end. At least that is the assumption upon which we go in entering into the discussion at all, for unless investigation is to lead to settled opinion it is of no service to us whatever. We do believe then in regard to every question which we try to investigate that the observations though they may be as varied and as unlike in themselves as possible, yet have some power of bringing about in our minds a predetermined state of belief. This reminds us of the species of necessity which is known as fate. The fairy stories are full of such examples as this: A king shuts his daughter up in a tower because he has been warned that she is destined to suffer some misfortune from falling in love before a certain age and it turns out that the very means which he has employed to prevent it is just what brings the prophecy to fulfillment. Had he pursued a different course, the idea seems to be that that would equally have brought about the destined result. Fate then is that necessity by which a certain result will surely be brought to pass according to the natural course of events however we may vary the particular circumstances which precede the event. In the same manner we seem fated to come to the final conclusion. For whatever be the circumstances under which the observations are made and by which they are modified they will inevitably carry us at last to this belief. [CP 7.334]

        The strangeness of this fact disappears entirely when we adopt the conception of external realities. We say that the observations are the result of the action upon the mind of outward things, and that their diversity is due to the diversity of our relations to these things; while the identity of the conclusion to which the mind is led by them is owing to the identity of the things observed, the reasoning process serving to separate from the many different observations that we make of the same thing the constant element which depends upon the thing itself from the differing and variable elements which depend on our varying relations to the thing. This hypothesis I say removes the strangeness of the fact that observations however different yield one identical result. It removes the strangeness of this fact by putting it in a form and under an aspect in which it resembles other facts with which we are familiar. We are accustomed very rightly to think that causes always precede their effects and to disbelieve in fate, which is a fancied necessity by which some future event as it were forces the conditions which precede to be such as would bring it about. That there is no such intrinsic and unconditional necessity to bring about events Western nations are fully and rightly convinced. This is why it seems strange to assert that the final conclusion of the investigation is predestined and why it is satisfactory to the mind to find a hypothesis which shall assign a cause preceding the final belief which would account for the production of it, and of the truth of this conception of external realities there can be no doubt. Even the idealists, if their doctrines are rightly understood have not usually denied the existence of real external things. But though the conception involves no error and is convenient for certain purposes, it does not follow that it affords the point of view from which it is proper to look at the matter in order to understand its true philosophy. It removes the strangeness of a certain fact by assimilating it to other familiar facts; but is not that fact that investigation leads to a definite conclusion really of so different a character from the ordinary events in the world to which we apply the conception of causation that such an assimilation and classification of it really puts it in a light which, though not absolutely false, fails nevertheless to bring into due prominence the real peculiarity of its nature? That observation and reasoning produce a settled belief which we call the truth seems a principle to be placed at the head of all special truths which are only the particular beliefs to which observation and reasoning in such cases lead. And it is hardly desirable to merge it among the rest by an analogy which serves no other purpose. [CP 7.335] . . . . . . . . . .

        The question is, "Whether corresponding to our thoughts and sensations, and represented in some sense by them, there are realities, which are not only independent of the thought of you, and me, and any number of men, but which are absolutely independent of thought altogether." The objective final opinion is independent of the thoughts of any particular men, but is not independent of thought in general. That is to say, if there were no thought, there would be no opinion, and therefore, no final opinion. [CP 7.336]
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        The final settled opinion is not any particular cognition, in such and such a mind, at such and such a time, although an individual opinion may chance to coincide with it. If an opinion coincides with the final settled opinion, it is because the general current of investigation will not affect it. The object of that individual opinion is whatever is thought at that time. But if anything else than that one thing is thought, the object of that opinion changes and it thereby ceases to coincide with the object of the final opinion which does not change. The perversity or ignorance of mankind may make this thing or that to be held for true, for any number of generations, but it can not affect what would be the result of sufficient experience and reasoning. And this it is which is meant by the final settled opinion. This therefore is no particular opinion but is entirely independent of what you, I, or any number of men may think about it; and therefore it directly satisfies the definition of reality." [CP 7.336n11]]
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        All that we directly experience is our thought—what passes through our minds; and that only, at the moment at which it is passing through. We here see thoughts determining and causing other thoughts, and a chain of reasoning or of association is produced. But the beginning and the end of this chain, are not distinctly perceived. A current is another image under which thought is often spoken of, and perhaps more suitably. We have particularly drawn attention to the point to which thought flows, and that it finally reaches: a certain level, as it were -- a certain basin, where reality becomes unchanging. It has reached its destination, and that permanency, that fixed reality, which every thought strives to represent and image, we have placed in this objective point, towards which the current of thought flows. [CP 7.337]

        But the matter has often been regarded from an opposite point of view; attention being particularly drawn to the spring, and origin of thought. It is said that all other thoughts are ultimately derived from sensations; that all conclusions of reasoning are valid only so far as they are true to the sensations; that the real cause of sensation therefore, is the reality which thought presents. Now such a reality, which causes all thought, would seem to be wholly external to the mind -- at least to the thinking part of the mind, as distinguished from the feeling part; for it might be conceived to be, in some way, dependent upon sensation. [CP 7.338]

        Here then are two opposite modes of conceiving reality. The one which has before been developed at some length, and which naturally results from the principles which have been set forth in the previous chapters of this book is an idea which was obscurely in the minds of the medieval realists; while the other was the motive principle of nominalism. I do not think that the two views are absolutely irreconcilable, although they are taken from very widely separated stand-points. The realistic view emphasizes particularly the permanence and fixity of reality; the nominalistic view emphasizes its externality. But the realists need not, and should not, deny that the reality exists externally to the mind; nor have they historically done so, as a general thing. That is external to the mind, which is what it is, whatever our thoughts may be on any subject; just as that is real which is what it is, whatever our thoughts may be concerning that particular thing. Thus an emotion of the mind is real, in the sense that it exists in the mind whether we are distinctly conscious of it or not. But it is not external because although it does not depend upon what we think about it, it does depend upon the state of our thoughts about something. Now the object of the final opinion which we have seen to be independent of what any particular person thinks, may very well be external to the mind. And there is no objection to saying that this external reality causes the sensation, and through the sensation has caused all that line of thought which has finally led to the belief. [CP 7.339]

        At first sight it seems no doubt a paradoxical statement that, "The object of final belief which exists only in consequence of the belief, should itself produce the belief"; but there have been a great many instances in which we have adopted a conception of existence similar to this. The object of the belief exists it is true, only because the belief exists; but this is not the same as to say that it begins to exist first when the belief begins to exist. We say that a diamond is hard. And in what does the hardness consist? It consists merely in the fact that nothing will scratch it; therefore its hardness is entirely constituted by the fact of something rubbing against it with force without scratching it. And were it impossible that anything should rub against it in this way, it would be quite without meaning, to say that it was hard, just as it is entirely without meaning to say that virtue or any other abstraction is hard. But though the hardness is entirely constituted by the fact of another stone rubbing against the diamond yet we do not conceive of it as beginning to be hard when the other stone is rubbed against it; on the contrary, we say that it is really hard the whole time, and has been hard since it began to be a diamond. And yet there was no fact, no event, nothing whatever, which made it different from any other thing which is not so hard, until the other stone was rubbed against it. [CP 7.340]

        So we say that the inkstand upon the table is heavy. And what do we mean by that? We only mean, that if its support be removed it will fall to the ground. This may perhaps never happen to it at all -- and yet we say that it is really heavy all the time; though there is no respect whatever, in which it is different from what it would be if it were not heavy, until that support is taken away from it. The same is true in regard to the existence of any other force. It exists only by virtue of a condition, that something will happen under certain circumstances; but we do not conceive it as first beginning to exist when these circumstances arise; on the contrary, it will exist though the circumstances should never happen to arise. And now, what is matter itself? The physicist is perfectly accustomed to conceive of it as merely the centre of the forces. It exists, therefore, only so far as these forces exist. Since, therefore, these forces exist only by virtue of the fact, that something will happen under certain circumstances, it follows that matter itself only exists in this way. [CP 7.341]

        Nor is this conception one which is peculiar to the physicists and to our views of the external world. A man is said to know a foreign language. And what does that mean? Only that if the occasion arises, the words of that language will come into his mind; it does not mean that they are actually in his mind all the time. And yet we do not say that he only knows the language at the moment that the particular words occur to him that he is to say; for in that way he never could be certain of knowing the whole language if he only knew the particular word necessary at the time. So that his knowledge of the thing which exists all the time, exists only by virtue of the fact that when a certain occasion arises a certain idea will come into his mind. [CP 7.342]

        A man is said to possess certain mental powers and susceptibilities, and we conceive of him as constantly endowed with these faculties; but they only consist in the fact that he will have certain ideas in his mind under certain circumstances; and not in the fact of his having certain ideas in his mind all the time. It is perfectly conceivable that the man should have faculties which are never called forth: in which case the existence of the faculties depends upon a condition which never occurs. But what is the mind itself but the focus of all the faculties? and what does the existence of the mind consist in but in these faculties? Does the mind cease to exist when it sleeps? and is it a new man who wakes every morning? [CP 7.343]

        It appears then that the existence of mind equally with that of matter according to these arguments which have led to this view which is held by all psychologists, as well as physicists, depends only upon certain hypothetical conditions which may first occur in the future, or which may not occur at all. There is nothing extraordinary therefore in saying that the existence of external realities depends upon the fact, that opinion will finally settle in the belief in them. And yet that these realities existed before the belief took rise, and were even the cause of that belief, just as the force of gravity is the cause of the falling of the inkstand -- although the force of gravity consists merely in the fact that the inkstand and other objects will fall. [CP 7.344]

        But if it be asked us, whether some realities do not exist, which are entirely independent of thought; I would in turn ask, what is meant by such an expression and what can be meant by it. What idea can be attached to that of which there is no idea? For if there be an idea of such a reality, it is the object of that idea of which we are speaking, and which is not independent of thought. It is clear that it is quite beyond the power of the mind to have an idea of something entirely independent of thought -- it would have to extract itself from itself for that purpose; and since there is no such idea there is no meaning in the expression. The experience of ignorance, or of error, which we have, and which we gain by means of correcting our errors, or enlarging our knowledge, does enable us to experience and conceive something which is independent of our own limited views; but as there can be no correction of the sum total of opinions, and no enlargement of the sum total of knowledge, we have no such means, and can have no such means of acquiring a conception of something independent of all opinion and thought. [CP 7.345]
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        Any mind which has the power of investigation, and which therefore passes from doubt to belief, must have its ideas follow after one another in time. And if there is to be any distinction of a right and a wrong method of investigation, it must have some control over the process. So that there must be such a thing as the production of one idea from another which was previously in the mind. This is what takes place in reasoning, where the conclusion is brought into the mind by the premises. [cP 7.346]

        We may imagine a mind which should reason and never know that it reasoned; never being aware that its conclusion was a conclusion, or was derived from anything which went before. For such a mind there might be a right and a wrong method of thinking; but it could not be aware that there was such a distinction, nor criticise in any degree its own operations. To be capable of logical criticism, the mind must be aware that one idea is determined by another. [CP 7.347]

        Now when this happens, after the first idea comes the second. There is a process which can only take place in a space of time; but an idea is not present to the mind during a space of time -- at least not during a space of time in which this idea is replaced by another; for when the moment of its being present is passed, it is no longer in the mind at all. Therefore, the fact that one idea succeeds another is not a thing which in itself can be present to the mind, any more than the experiences of a whole day or of a year can be said to be present to the mind. It is something which can be lived through; but not be present in any one instant; and therefore, which can not be present to the mind at all; for nothing is present but the passing moment, and what it contains. The only way therefore in which we can be aware of a process of inference, or of any other process, is by its producing some idea in us. Not only therefore is it necessary that one idea should produce another; but it is also requisite that a mental process should produce an idea. These three things must be found in every logical mind: First, ideas; second, determinations of ideas by previous ideas; third, determinations of ideas by previous processes. And nothing will be found which does not come under one of these three heads. [CP 7.348]

        The determination of one thing by another, implies that the former not only follows after the latter, but follows after it according to a general rule, in consequence of which, every such idea would be followed by such a second one. There can therefore be no determination of one idea by another except so far as ideas can be distributed into classes, or have some resemblances. But how can one idea resemble another? An idea can contain nothing but what is present to the mind in that idea. Two ideas exist at different times; consequently what is present to the mind in one is present only at that time, and is absent at the time when the other idea is present. Literally, therefore, one idea contains nothing of another idea; and in themselves they can have no resemblance. They certainly do not resemble one another except so far as the mind can detect a resemblance; for they exist only in the mind, and are nothing but what they are thought to be. Now when each is present to the mind the other is not in the mind at all. No reference to it is in the mind, and no idea of it is in the mind. Neither idea therefore when it is in the mind, is thought to resemble the other which is not present in the mind. And an idea can not be thought, except when it is present in the mind. And, therefore, one idea can not be thought to resemble another, strictly speaking. [CP 7.349]

        In order to escape from this paradox, let us see how we have been led into it. Causation supposes a general rule, and therefore similarity. Now so long as we suppose that what is present to the mind at one time is absolutely distinct from what is present to the mind at another time, our ideas are absolutely individual, and without any similarity. It is necessary, therefore, that we should conceive a process as present to the mind. And this process consists of parts existing at different times and absolutely distinct. And during the time that one part is in the mind, the other is not in the mind. To unite them, we have to suppose that there is a consciousness running through the time. So that of the succession of ideas which occur in a second of time, there is but one consciousness, and of the succession of ideas which occurs in a minute of time there is another consciousness, and so on, perhaps indefinitely. So that there may be a consciousness of the events that happened in a whole day or a whole life time. [CP 7.350]

        According to this, two parts of a process separated in time -- though they are absolutely separate, in so far as there is a consciousness of the one, from which the other is entirely excluded -- are yet so far not separate, that there is a more general consciousness of the two together. This conception of consciousness is something which takes up time. It seems forced upon us to escape the contradictions which we have just encountered. And if consciousness has a duration, then there is no such thing as an instantaneous consciousness; but all consciousness relates to a process. And no thought, however simple, is at any instant present to the mind in its entirety, but it is something which we live through or experience as we do the events of a day. And as the experiences of a day are made up of the experiences of shorter spaces of time so any thought whatever is made up of more special thoughts which in their turn are themselves made up by others and so on indefinitely. [CP 7.351]

        It may indeed very likely be that there is some minimum space of time within which in some sense only an indivisible thought can exist and as we know nothing of such a fact at present we may content ourselves with the simpler conception of an indefinite continuity in consciousness. It will easily be seen that when this conception is once grasped the process of the determination of one idea by another becomes explicable. What is present to the mind during the whole of an interval of time is something generally consisting of what there was in common in what was present to the mind during the parts of that interval. And this may be the same with what is present to the mind during any interval of time; or if not the same, at least similar -- that is, the two may be such that they have much in common. These two thoughts which are similar may be followed by others that are similar and according to a general law by which every thought similar to either of these is followed by another similar to those by which they are followed. If a succession of thoughts have anything in common this may belong to every part of these thoughts however minute, and therefore it may be said to be present at every instant. This element of consciousness which belongs to a whole only so far as it belongs to its parts is termed the matter of thought. [CP 7.352]

        There is besides this a causation running through our consciousness by which the thought of any one moment determines the thought of the next moment no matter how minute these moments may be. And this causation is necessarily of the nature of a reproduction; because if a thought of a certain kind continues for a certain length of time as it must do to come into consciousness the immediate effect produced by this causality must also be present during the whole time, so that it is a part of that thought. Therefore when this thought ceases, that which continues after it by virtue of this action is a part of the thought itself. In addition to this there must be an effect produced by the following of one idea after a different idea; otherwise there would be no process of inference except that of the reproduction of the premises. [CP 7.353]
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        We have seen that an inference is the process by which one belief determines another. But a belief is itself a habit of the mind by virtue of which one idea gives rise to another. When I say that I know the French language, I do not mean that as long as I know it I have all the words which compose it in my mind, or a single one of them. But only that when I think of an object, the French word for it will occur to me, and that when a French word is brought to my attention I shall think of the object it signifies. What is true of knowledge is equally true of belief, since the truth or falsehood of the cognition does not alter its character in this respect. I believe that prussic acid is poison, and always have believed it. This does not mean that I have always had the idea of prussic acid in my mind, but only that on the proper occasion, on thinking of drinking it, for example, the idea of poison and all the other ideas that that idea would bring up, would arise in my mind. [CP 7.354]

        Thus there are three elements of cognition: thoughts, the habitual connection between thoughts, and processes establishing a habitual connection between thoughts. We have seen already that an idea cannot be instantaneously present, that consciousness occupies time, and that we have no consciousness in an instant. So that at no time have we a thought. But now it further appears that in reference to a belief not only can we not have it in an instant, but it can not be present to the mind in any period of time. It does not consist in anything which is present to the mind, but in an habitual connection among the things which are successively present. That is to say, it consists in ideas succeeding one another according to a general rule; but not in the mere thinking of this general rule, nor in the mere succession of ideas one upon another, nor in both together. A thought must therefore be a sign of a belief; but is never the belief itself. The same thing is obviously true in regard to an inference; and even a simple idea is of intellectual value to us not for what it is in itself but as standing for some object to which it relates. Now a thing which stands for another thing is a representation or sign. So that it appears that every species of actual cognition is of the nature of a sign. It will be found highly advantageous to consider the subject from this point of view, because many general properties of signs can be discovered by a set of words and the like which are free from the intricacies which perplex us in the direct study of thought. [CP 7.355]

        Let us examine some of the characters of signs in general. A sign must in the first place have some qualities in itself which serve to distinguish it, a word must have a peculiar sound different from the sound of another word; but it makes no difference what the sound is, so long as it is something distinguishable. In the next place, a sign must have a real physical connection with the thing it signifies so as to be affected by that thing. A weather-cock, which is a sign of the direction of the wind, must really turn with the wind. This word in this connection is an indirect one; but unless there be some way or other which shall connect words with the things they signify, and shall ensure their correspondence with them, they have no value as signs of those things. Whatever has these two characters is fit to become a sign. It is at least a symptom, but it is not actually a sign unless it is used as such; that is unless it is interpreted to thought and addresses itself to some mind. As thought is itself a sign we may express this by saying that the sign must be interpreted as another sign. Let us see however, whether this is true of thought itself that it must address itself to some other thought. There are some cases in which it is not difficult to see that this must be the case. I have no belief that prussic acid is poisonous unless when the particular occasion comes up I am led to the further belief that that particular acid is poisonous; and unless I am further led to the belief that it is a thing to avoid drinking. For all these things are necessary to my acting on my belief. A belief which will not be acted on ceases to be a belief. [CP 7.356]

        It may be that I shall finally come to a belief which is a motive for action directly without the intervention of a more special belief. In this case how does the belief address itself to a sign? When a person is said to act upon a certain belief the meaning is that his actions have a certain consistency; that is to say, that they possess a certain intellectual unity. But this implies that they are interpreted in the light of thought. So that even if a belief is a direct motive to action it still is a belief only because that action is interpretable again. And thus the intellectual character of beliefs at least are dependent upon the capability of the endless translation of sign into sign. An inference translates itself directly into a belief. A thought which is not capable of affecting belief in any way, obviously has no signification or intellectual value at all. If it does affect belief it is then translated from one sign to another as the belief itself is interpreted. And therefore this character of signs that they must be capable of interpretation in every sense belongs to every kind of cognition. And consequently no cognition is such or has an intellectual significance for what it is in itself, but only for what it is in its effects upon other thoughts. And the existence of a cognition is not something actual, but consists in the fact that under certain circumstances some other cognition will arise. [CP 7.357]
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        In every logical mind there must be 1st, ideas; 2nd, general rules according to which one idea determines another, or habits of mind which connect ideas; and, 3rd, processes whereby such habitual connections are established. [CP 7.358]

        A belief is an habitual connection of ideas. For example, to say that I believe prussic acid is a poison is to say that when the idea of drinking it occurs to me, the idea of it as a poison with all the other ideas which follow in the train of this will arise in my mind. Among these ideas, or objects present to me, is the sense of refusing to drink it. This, if I am in a normal condition, will be followed by an action of the nerves when needed which will remove the cup from my lips. It seems probable that every habitual connection of ideas may produce such an effect upon the will. If this is actually so, a belief and an habitual connection of ideas are one and the same. [CP 7.359]

        In a mind which is capable of logical criticism of its beliefs, there must be a sensation of believing, which shall serve to show what ideas are connected. The recognition that two objects present belong together as one is a judgment. All ideas arise in judgments. This is clearly the case if they are caused by previous ideas. If they are sensations then they at once cause other ideas and are connected with these in judgments. The intellectual value of ideas lies evidently in their relations to one another in judgments and not to their qualities in themselves. All that seems blue to me might seem red and vice versa and yet all that I now find true of those objects I should equally find true then, if nothing else were changed. I should still perceive the same distinctions of things that I do now. The intellectual significance of beliefs lies wholly in the conclusions which may be drawn from them, and ultimately in their effects upon our conduct. For there does not seem to be any important distinction between two propositions which never can yield different practical results. Only the difference in the facility with which a conclusion can be reached from two propositions must be regarded as a difference in their effects upon our actions. [CP 7.360]

        It appears then that the intellectual significance of all thought ultimately lies in its effect upon our actions. Now in what does the intellectual character of conduct consist? Clearly in its harmony to the eye of reason; that is in the fact that the mind in contemplating it shall find a harmony of purposes in it. In other words it must be capable of rational interpretation to a future thought. Thus thought is rational only so far as it recommends itself to a possible future thought. Or in other words the rationality of thought lies in its reference to a possible future. [CP 7.361]