Home Page      Peirce Papers      Intro to L75      L75 Version 2



  Final Version - MS L75.362-363  

MEMOIR    11


(This memoir is here placed, or perhaps better before No. 9, for the sake of perspicuity of exposition. The matter of it will have to be somewhat transformed at a later stage.)

     If the logician is to talk of the operations of the mind at all, as it is desirable that he should do, though it is not scientifically indispensable, then he must mean by "mind" something quite different from the object of study of the psychologist; and this logical conception of mind is developed in this memoir and rendered clear.

      (My order of arrangement of the first eleven memoirs is subject to reconsideration. The categories are applicable to the logical analysis of mathematics. It is even a question whether this fact does not derange my classification, although I have carefully considered it, and have provisionally concluded that it does not. It further seems to me better to let the categories first emerge in the mathematical memoirs before explicitly considering them. This is a question of methodeutic, which is not so exact in its conclusions as is critical logic. I think the arrangement I here propose is favorable to the reception of the categories. But if I were to decide to postpone the mathematical memoirs until after the categories, they might better be placed last among the first eleven memoirs. In that case, also, and indeed in any case, it might be well to place the memoir on the logical conception of mind before that upon esthetics and ethics. The present arrangement has been pretty carefully considered; and the last transposition is the only one that I think there is much likelihood of my deciding upon. After No. 12, the only changes possible are shifts of boundaries in order to equalize the lengths of memoirs.)

* * *

  From Draft E - MS L75.162-163  

      If the logician is to talk of mind and its operations at all, it must be in a different sense from that in which modern psychologists study the mind. This conception of mind, which is needed in our studies, will be developed in its four successive grades of clearness.

* * *

  From Draft D - MS L75.233-235  

      It is almost universally held that logic is a science of thought (so far as it is a science at all), that thought is a modification of consciousness, and that consciousness is the object of the science of psychology. The effect of this, were it perceived, is to make logic logically dependent upon the very one of all the special sciences which most stands in logical need of a science of logic. Accordingly, we find that some logicians deny that logic is a science, while others maintain that it is a mere description of our feelings. Each of these views has had disastrous effects upon several branches of science. It has occurred to me that perhaps logic relates to mind in one sense of the word "mind", and that the psychologists inquire into the phenomena of mind in another sense of "mind". It is beyond my province to say what the psychologists aim to study; but it is perfectly proper for me to determine by analysis what mind is in the sense in which logic is concerned with it. I have performed this analysis; and I believe that it will be found convincing, somewhat novel, highly interesting, and decidedly elevating. Indeed, I promise myself that if ever this memoir receives the attention that it ought, it will do something appreciable to aid the movement now beginning to extricate science from the slough of materialism. I undertake to show that when a man performs the simplest voluntary act, the nature of his efficiency upon matter is precisely the same as that which we attribute to truth when we say "Truth, crushed to earth, shall rise again," in which most scientific men have more or less faith. I will further make it mathematically evident that to say that while matter can act immediately only upon matter and mind can immediately act only upon mind, and yet each can act upon the other without the intervention of a tertium quid, does not involve the self-contradiction which it appears at first blush to express. At the same time, I show that there is nothing which it properly belongs to the logician to say about mind, in his sense, which cannot be established on the basis of universal experience, without appealing to any special science whatever.



  Final Version - MS L75.363-364  



      Logic will here be defined as formal semiotic. A definition of a sign will be given which no more refers to human thought than does the definition of a line as the place which a particle occupies, part by part, during a lapse of time. Namely, a sign is something, A, which brings something, B, its interpretant sign determined or created by it, into the same sort of correspondence with something, C, its object, as that in which itself stands to C. It is from this definition, together with a definition of "formal", that I deduce mathematically the principles of logic. I also make a historical review of all the definitions and conceptions of logic and show not merely that my definition is no novelty, but that my non-psychological conception of logic has virtually been quite generally held, though not generally recognized.

* * *

  From Draft D - MS L75.235-237  

      I define logic very broadly as the study of the formal laws of signs, or formal semiotic. I define a sign as something, A, which brings something, B, its interpretant, into the same sort of correspondence with something, C, its object, as that in which itself stands to C. In this definition I make no more reference to anything like the human mind than I do when I define a line as the place within which a particle lies during a lapse of time. At the same time, a sign, by virtue of this definition, has some sort of meaning. That is implied in correspondence. Now meaning is mind in the logical sense. But many will object that the only signs we can study are signs interpreted in human thought. I reply that by the definition thoughts are themselves signs, and that if it happens to be a fact that all other signs are ultimately interpreted in thought-signs, then that fact is irrelevant to logic. The proof that it is irrelevant is that all the principles of logic are deducible from my definition without taking any account of the alleged fact, much more clearly than if any attempt is made to introduce this allegation as a premiss. Therefore, unless this allegation be regarded as itself a truth of logic, which it is not, since it is not of a formal nature, it is perfectly irrelevant to logic. I also define very carefully what I mean by a "formal" law. I say nothing in the definition about normative principles, because not all the principles of logic are normative. Indeed, it is only the connection of logic with esthetics through ethics which causes it to be a normative science at all.

      The above argument is hard to escape but not convincing. In order to render it so, I am obliged to review about fifty attempts to define logic and to show that the consideration of them only leads back to that one.

* * *

  From Draft C - MS L75.143-147  

      We cannot safely employ in logic any kind of reasoning which is subject to doubts which a science of logic is needed to remove. We are, therefore, restricted to mathematical reasoning. Now mathematical reasoning requires a diagrammatic or pure constructive notion of the thing reasoned about. But the ordinary logicians talk of acts of the mind, concepts, judgments, acts of concluding, which are mixed ideas into which enter all sorts of elements in a manner which prevents any strict mathematical reasoning about them. All these ideas of the mind are, however, representations, or signs. We must begin by getting diagrammatic notions of signs from which we strip away, at first, all reference to the mind; and after we have made those ideas just as distinct as our notion of a prime number or of an oval line, we may then consider, if need be, what are the peculiar characteristics of a mental sign, and in fact may give a mathematical definition of a mind in the same sense in which we can give a mathematical definition of a straight line. We cannot by any purely mathematical definition build up the peculiar idea of straightness, since that is nothing but a feeling. We can only define a straight line as one of a continuous family of lines having certain relations to one another. But there might be just such a family composed of lines none of which would appear straight to us. In like manner, we can define the formal character of mind in a manner perfectly adequate to all the purposes of logic. But there is nothing to compel the object of such a formal definition to have the peculiar feeling of consciousness. That peculiar feeling has nothing to do with the logicality of reasoning, however; and it is far better to leave it out of account.

      In this paper, then, I shall precisely analyze and define the various kinds of signs and their characteristics. Of course, I cannot trace out the development here. But I may say that I begin by dividing all signs into icons, indices, and symbols. An icon is a sign which is such by virtue of a character which it might equally possess if the object it represents had no being (although of course it could not then be a sign) and which it might equally possess if it never were interpreted in another sign. Thus a chalk mark on a blackboard may serve as the icon of a geometrical line. This is because it is long and slender. But it would be long and slender just the same even if the geometrical line had no kind of being. An icon is therefore a sign by virtue of its own quality and is a sign of whatever else partakes of that quality. An index, on the other hand, is a sign which is such because it is in reaction or real relation with its object, and would be so, just the same, though it never were interpreted as a sign. So a weathercock is a sign of the direction of the wind. A symbol is a sign which is such, not by the mere virtue of a quality which agrees with that of its object, nor by virtue of any mechanical connection with its object, but simply because it is interpreted as a sign in another sign. We have a somewhat imperfect example in the small hand of an alarm clock which is set to cause the bell to ring when the time according to the clock is a given hour. This little hand is a sign of the clock's having gone to the hour, not because it follows the large hand, or because it will at that hour be parallel to the large hand (which may or may not be the case), but because the bell will ring when the clock has run to the hour which the little hand indicates. The bell is the interpreting sign. So when a person reads aloud from a book, the print is a sign simply by virtue of the fact that the voice will so interpret it; or if the book is read silently, the succession of images in the mind will so interpret it. It may be objected that no kind of sign operates as a sign unless it is interpreted. This is quite true; but in the cases of the icon and index, it is possible to leave that circumstance out of account, as in fact we commonly do, and still have a perfectly correct idea of the relation of the sign to its object. But in the case of the symbol, if the fact of its being interpreted is left out of account, its peculiar relation to its object will be left out of account. A chalk mark is like a line though nobody uses it as a sign; a weathercock turns with the wind, whether anybody notices it or not. But the word "man" has no particular relation to men unless it be recognized as being so related. That is not only what constitutes it a sign, but what gives it the peculiar relation to its object which makes it significant of that particular object.



  Final Version - MS L75.364-365  



      By an application of categoric, I show that the primary division of logic should be into stechiology, critic, and methodeutic. There is a cross-division into the doctrines of terms, propositions, and arguments, to which three kinds of signs, however, stechiology, critic, and methodeutic are quite differently related. The various historical divisions of logic are considered.

EDITORIAL NOTE: Other Peircean terms for "stechiology" (or "stechiologic") are e.g. "universal grammar", "speculative grammar", and "philosophical grammar". "Critic" is usually referred to as "critical logic" or simply as "logic" (in what he calls "the narrow sense," in distinction from the broad sense in which it is equivalent to "semiotic"). "Methodeutic" is also "universal rhetoric", "speculative rhetoric", and "philosophical rhetoric".

* * *

  From draft E - MS L75.164-165  

      Logic is primarily divided into stechiologic, critic, and methodeutic, which are defined in terms of the categories. Logic relates to terms, propositions, and arguments. Stechiologic treats of every variety. Critic has no direct bearing upon terms, upon analytic, or explicatory, propositions, nor upon necessary reasoning as such. It does, however, treat of meaningless and absurd terms, of irrelevant definitions, of fallacious demonstrations and of probable deductions. Methodeutic has no direct bearing upon any terms or propositions or upon any kind of reasoning except that which starts hypotheses. After critical logic has pronounced a hypothesis to be justifiable (being a verifiable hypothesis which explains the surprising fact), it remains to submit the hypothesis to methodeutic in order to determine whether it should be the first among the justifiable hypotheses to be considered. No such supplementary inquiry is called for in the case of a deductive or an inductive conclusion. Indirectly, however, methodeutic treats of all kinds of signs.

      The history of divisions of logic is examined; and it is shown that my division has been virtually quite generally approved, except so far as it has been deranged by other divisions I make.

* * *

  From Draft D - MS L75.237-244  

      By virtue of the categories, anything whatever may be considered under three aspects; first, in its peculiar flavor; second, as reacting with an object; and third, as represented. The peculiar flavor which belongs to a sign, as such, is its imputed flavor, or meaning. The object upon which a sign as such reacts is the object to which it corresponds, or denotes. The representamen which belongs to a sign as such is its interpretant. Consequently, formal semiotic falls into three departments, the study of those laws to which a sign must conform in order to mean what it is to mean, the study of the laws to which a sign must conform in order really to correspond to the object to which it is intended to conform, that is, to be true, and those laws to which a sign must conform in order to determine the interpretant to which it is intended to appeal, that is, to advance knowledge. These three departments have been called stechiologic, critic, and methodeutic. I regard this division as primary, because it depends upon a principle which is applicable to anything whatsoever.

      The categories show that signs are themselves of three kinds. For a sign may have as its sign-flavor, or significant character, merely the flavor, or quality, which belongs to it just as anything has a flavor or quality; and in this case it will stand for whatever its thing-flavor adapts it to standing for. Such is an icon, or image, which represents any object just so far as it resembles that object. Or, secondly, a sign may have as its significant character the fact that it stands in real relation to its object. It will then serve as a sign of that object to any interpretant that represents it as so reacting with that object. This is an index. Or, finally, a sign may have as its significant character its being represented to be a sign. That is a symbol. All merely conventional signs are symbols; and so are all signs which become such because they are naturally taken to be such, as ideas. Logic might, perhaps, properly be restricted to symbols. I have not paid sufficient attention, perhaps, to the formal laws of indices and icons to see that the study of them ought to be separated from that of symbols. My not very decided opinion is that they should all be studied together.

      But another division of signs, especially of symbols, is shown by the categories. For a sign may be such that it shall denote whatever object it may be fitted to denote and appeal to whatever interpretant may be fitted to interpret it. Such is a name. Every pure icon is necessarily of this description. Secondly, a sign may separately indicate the object which it is intended to denote, but may appeal to whatever interpretant can interpret it. Such is a proposition. Thirdly, a sign may definitely signify what interpretant sign it is intended to determine. If it does this, it must also indicate what object it is intended to denote; because, if it separately signifies what interpretant is to be determined, whatever is the object of the sign is thereby separately indicated as the object of the interpretant. Such a sign definitely signifying what interpretant it is intended to determine is an argument, of which the conclusion is the intended interpretant. Symbols alone can be arguments, which accounts for the small importance of icons and indices in logic. We thus have a division of signs into terms, propositions, and arguments; and consequently there is a cross division of logic into the doctrine of terms, the doctrine of propositions, and the doctrine of arguments.

      Making the former division the primary one, stechiology will have direct concern with terms, propositions, and arguments. Critic, however, whose business it is to consider whether signs are really related to their objects, that is, are true, can have no direct concern with terms, since a term simply denotes whatever object it is fit to denote. Methodeutic, for a similar reason, can have no direct and primary concern with anything but arguments, notwithstanding the great part that definition and division have always played in this branch of logic. Moreover, critic cannot directly deal with all kinds of propositions, since there can be no question as to the truth of a definition. Nor can it directly deal with all kinds of arguments. For there can be no general theory proving the general validity of necessary reasoning. For such reasoning makes its conclusion evident; and so long as it is evident, there is [no] doubt about it to be removed. I know that this will be contested; but I shall show in another memoir that the objections are due to confusion of thought. In like manner, the direct concern of methodeutic is restricted still more narrowly to a single class of arguments. But it will be shown that, notwithstanding these considerations, the indirect relation of critic and methodeutic to those signs which do not directly concern them is important.

      I shall then proceed to the critical examination of the different modes of dividing logic, and shall show that the above divisions have been generally recognized, and that others are not, properly, divisions of logic itself, or are mere subdivisions of little importance.



  Final Version - MS L75.465-366  



      I shall here show that no less than thirteen different methods of establishing logical truth are in current use today, and mostly without any principle of choice and in a deplorably uncritical manner.

      I shall show that the majority of these methods are quite inadmissible, and that of the remainder all but one should be restricted to one department of logic. The one universally valid method is that of mathematical demonstration; and this is the only one which is commonly avoided by logicians as fallacious. I shall show in the clearest manner that this notion is due to a confusion of thought, which I shall endeavor to trace through all its metamorphoses. I hope to give this its quietus.

      The methods of discovering logical truth can naturally not be numerous when discovery is pretty nearly at a standstill. I explain my own method.

* * *

  From Draft D - MS L75.245-247  

      It need not be said that a science whose methods are all at sixes and sevens is in poor case. I shall show that there are at present actually in use six plus seven, or thirteen methods in use for establishing logical truth, without counting the method of authority which is really operative, although unavowed. While there are some logicians who are more or less scrupulous in their choice of methods, most of them resort indifferently to any one of twelve, the only one they scrupulously avoid being the only one that is generally valid. For I shall prove conclusively that the majority of the methods are absolutely worthless, and that of the others only one is properly applicable in all parts of logic. That one method consists in proceeding from universally observed facts, formulated abstractly, and deducing their consequences by mathematical reasoning. We are here with certain objections which weigh with almost all logicians but which I shall undertake to show are merely due to a feeble grasp of the conceptions of logic. This first of these objections, which lies behind them all, is that, logic being the science which establishes the validity of reasoning, it begs the question to employ reasoning to establish the principles of logic. To this I reply that as long as all doubt is removed by a method, nothing better can be demanded. But owing to the confused state of mind of logicians, they make various attempts to answer this, such as that doubt is not removed if we question the validity of the reasoning. The rejoinder is obvious enough. Of course, it follows that pure mathematics does not stand in need of any science of logic to determine whether a reasoning is good or not; and by a review of the different disputes which have arisen between mathematicians, I show that this is the case; and I contrast this with a number of instances in the history of other sciences, where logical doctrines were sadly needed.

      In regard to methods of discovering logical truth, there are few logicians who show any vestige of any definite method except that of reading what others have written. There are, however, a few methods which have been employed, which I consider. I show that the most successful of these really consist in an unconscious and ill-defined application of one method which I describe.

* * *

  From Draft A- MS L75.33-35  

      No less than thirteen different ways are employed by different logicians for ascertaining what is good reasoning and what is bad reasoning. Only one of these thirteen methods is generally employed by me, although there are one or two of the others which I apply to a very limited extent as confirmatory only in settling minute details. The great mass of the twelve methods I regard as altogether unscientific and worthless in scientific logic, though there are certain unscientific and inexact parts of logic, where reasoning is mainly regulated by the logical instinct, where there is no particular objection to their use. In particular, I hold the ordinary subjective method of the German logicians--which bases logic upon the feeling of logicality to such an extent that good reasoning is defined as such reasoning as we deliberately approve as satisfying that feeling--to be simply disastrous to science, to be much worse than leaving the whole question to the direct decision of instinct, and to be responsible for grave errors of procedure in the German psychical science, as for example in linguistics, in the historical criticism of documents, etc.

      I undertake to show that every reasoning professes to proceed according to a method that is calculated to lead to the truth; and a good reasoning is a reasoning which in fact fulfills its profession in this respect.

* * *

  From Draft B - MS L75.10-18  

      [I] will give some preliminary idea of the present state of logical inquiry. It will be shown that thirteen different ways of determining whether reasoning is good or bad are now in use, to my knowledge. Most of these will be shown to be worthless. A few may be sparingly employed in special cases to which they are adapted. But one sole method is generally valid. Namely, it must be shown that whatever be the constitution of the universe, the method of reasoning adopted, if it leads to any conclusion, and if there is any such thing as the Truth to be reached, must in the long run reach a true conclusion. The doctrine to which this is prominently opposed is that the only way of judging of the validity of a reasoning is by means of our instinctive feeling of rationality. My position against this subjective logic is this. The instinct of rationality is not a simple feeling. It is a faculty which produces distinct judgments; and the matter of any such judgment is that a given method of reasoning is good or bad, that is, will or will not answer its purpose as certainly and completely as any that can be found. The instinctive judgment of rationality, therefore, makes its pronouncement relative to the reasoner's purpose. For that reason, it is necessary to consider separately theoretical reasonings, the reasonings of pure science, and practical reasonings, the reasonings of a person about the affairs of life. The latter proposes to act speedily upon his conclusion; so that the question must be settled with some degree of promptitude. Science, on the other hand, may be a century, or five centuries, engaged upon an investigation. Indeed, there is no definite period within which science must reach its final conclusion. Therefore, if it is quite evident that a method of reasoning is such that it must reach the truth in the long run of probabilities, while it may not be so good a method as some other where the approximation is more rapid, yet it cannot be pronounced absolutely bad for scientific purposes. The voice of instinct itself, when closely cross-questioned, assents to this. For if we consider two methods of reasoning which the instinctive sense of rationality in the first instance pronounces to be upon a par, and if we show, as we can, that one of these will evidently lead to the truth in the long run, if it leads to any conclusion and if there is any truth, while as to the other, it is evident that there is no such necessity, instinct will change its mind and prefer the method which the objective criterion prefers. Indeed, instinct confesses its own inadequacy to decide upon reasonings which may be continued through many ages. But in the case of a person's practical reasonings the case is different. For an individual whose purse is finite, there really is no such thing as the "long run" of probabilities. The objective theory is not strictly applicable. Besides, here instinct is within its own proper domain; and instinct, within its proper domain is far keener and surer than any human theory whatever. Practical reasonings, therefore, ought not to be guided by scientific logic, but by instinct; and the only logic which is applicable to them consists in unsystematic generalizations of instinct. But in proportion as the person practices a true ethics and is animated by the purpose behind Nature at large, in that proportion will it be possible for his reasonings to become scientifically logical.

      A pair of closely connected objections, however, are commonly urged against the objective criterion in logic; and these are so obvious and specious that I think I ought, even in this brief statement, to give some idea of how I would reply to them. Namely, the subjectivist says: "You propose to ascertain whether reasoning is good or bad, how? Why, by reasoning. But how are you to know that this reasoning is good, unless you trust to instinct? Besides, reasoning proceeds from premisses; now on what do you found these premisses, if you will not trust to instinct? If you say, on experience, the answer is that a premiss is a proposition, while experiences are perceptions, not propositions. How do you know that your first proposition is true to the perception? Nor can all your premisses by perceptual facts. You must go on some general principle, and that can only be accepted if you trust to instinct." But these objections involve three errors. In the first place, they virtually insist that if I believe a single statement made by a witness, I am bound to believe all he says. In the second place, they overlook the fact that it is idle and nugatory for a court to condemn a party who is beyond the reach of its arm. In the third place, they approve the proceeding of a man who because he cannot check his expenses accurately to a cent, does not think it worthwhile to keep any accounts at all. All these errors belong to the class of exaggerations. Exaggeration is the besetting sin of philosophers.

      Consider a case in which the instinct of rationality declares with absolute decisiveness that one proposition follows from another. In such a case, to the man it appears perfectly evident that the consequence holds. For what is the instinct of rationality? It is that disposition of a man's soul or constitution which causes him to hold certain things to be reasonable. If the dictum of instinct is so absolute, the man is forced to believe it, and cannot doubt it. It is not a case of trusting to instinct. He need not know he has any such instinct. If anybody asks why do you believe this, he may properly reply, "For the same reason that when I look at a red thing, I believe that it looks red; I see it, and cannot doubt it. Not doubting it, or ever having doubted it, I really have no reason for accepting it. I cannot help accepting it; and blaming myself for doing so would not enable me to doubt it. There is, therefore, no use in worrying." The man may, quite consistently, hold instinct to be most treacherous and deceptive. But still, that which instinct absolutely requires him to believe, he must and will believe with his whole heart.

      The objectivist logician criticizes his beliefs so far as he can exercise any control over them. He criticizes them by reasoning; and he criticizes that reasoning so far as he can exercise any control over it. Thus he might conceivably go over his reasonings again and again endlessly. But, in fact, he soon comes to something that seems so perfectly evident that he cannot doubt it. There he is obliged to stop. Perhaps the next day, he finds a way of doubting it; but finally he comes to something where he seems evidently to see that no revision of his opinion ever could make him doubt.

      When a consequence is mathematically evident, it is nonsense to talk of applying any criterion to it, either to strengthen it (as if there could be a larger share than All) or to weaken it (as if anything could weaken the evident). That is the rational view. If you choose to take an exterior standpoint, the consequence that appears evident the man is absolutely forced to believe. It would be nonsense to say that the force of conviction could be increased, equal nonsense to say that if he is unconditionally forced to believe it, the force can be diminished. How could such increase or diminution manifest themselves?

      As to the premisses, it is plain that the operation of forming perceptual judgments from percepts is beyond our control, and therefore beyond criticism. So are certain generalizations from ordinary experience. As Jesus, in the Bible, suggests that "He who is without sin among you, cast the first stone," so I would say, let he who really has the first doubt of the general truths of experience commence the attack on objective logic.


End of PART 5 of 10 of MS L75


Queries, comments, and suggestions to
Joseph Ransdell -- Dept of Philosophy
Texas Tech University, Lubbock Texas 79409

Scholarly quotation from or reference to
the content of this website will mention
the URL of the web-page where the content occurs.

The URL of the present page, which is part of the Arisbe website, is

Page last modified June 15, 1998

Top of the Page