Digital Companion to C. S. Peirce
1865 | Harvard Lectures on the Logic of Science. Lecture VIII: Forms of Induction and Hypothesis | W 1:257-258

By a symbol I mean [a representation] which upon being presented to the mind - without any resemblance to its object and without any reference to a previous convention - calls up a concept. I consider concepts, themselves, as a species of symbols.

A symbol is subject to three conditions. 1st it must represent an object or informed and representable thing. Second it must be a manifestation of logos, or represented and realizable form. Third it must be translatable into another language or system of symbols.

1865 | Teleological Logic | W 1:303-304

Representations are of three kinds according to their truth or coincidence with their objects. These are

     1. Signs. Representations by virtue of convention.
     2. Symbols. Representations by virtue of original or acquired nature.
     3. Copies. Representations by virtue of a sameness of predicates.

By a symbol is meant such a representation as is regarded as a representation in another system of representations.

1865 | Logic of the Sciences | W 1:328

Representations whose subject depends upon its object. That is which are intelligible to those who can comprehend a certain character of the object - if there are several objects, a common character. It is this sort of representation which a conception is; and which a word is, after it has once been acquired as a sign. I call this species of representation Symbol.

1865 | Logic of the Sciences | W 1:323

A type/symbol is a representation whose correspondence with its object is of the same immaterial kind as a sign but is founded nevertheless in its very nature and is not merely supposed and fictitious.

1866 | Lowell Lectures on The Logic of Science; or Induction and Hypothesis: Lecture IX | W 1:475

A symbol is a general representation like a word or conception. [—] A symbol is a representation whose essential Quality and Relation are both unprescindible - the Quality of being Imputed and the Relation ideal.

1866 | Lowell Lectures on The Logic of Science; or Induction and Hypothesis: Lecture VII | W 1:468

The third and last kind of representations are symbols or general representations. They connote attributes and so connote them as to determine what they denote. To this class, belong all words and all conceptions. Most combinations of words are also symbols. A proposition, an argument, even a whole book may be, and should be, a single symbol.

1867 | On a New List of Categories | W 2:55-56

A reference to a ground may also be such that it cannot be prescinded from a reference to an interpretant. In this case it may be termed an imputed quality. If the reference of a relate to its ground can be prescinded from reference to an interpretant, its relation to its correlate is a mere concurrence or community in the possession of a quality, and therefore the reference to a correlate can be prescinded from reference to an interpretant. It follows that there are three kinds of representations.

1st. Those whose relation to their objects is a mere community in some quality, and these representations may be termed Likenesses.

2d. Those whose relation to their objects consists in a correspondence in fact, and these may be termed Indices or Signs.

3d. Those the ground of whose relation to their objects is an imputed character, which are the same as general signs, and these may be termed Symbols.

1893-1895 [c.] | Division III. Substantial Study of Logic. Chapter VI. The Essence of Reasoning | MS 409:95-96

It seems certainly the truest statement for most languages to say that a symbol is a conventional sign which being attached to an object signifies that that object has certain characters. But a symbol, in itself, is a mere dream; it does not show what it is talking about. It needs to be connected with its object. For that purpose, an index is indispensable. No other kind of sign will answer the purpose. That a word cannot in strictness of speech be an index is evident from this, that a word is general - it occurs often, and every time it occurs, it is the same word, and if it has any meaning as a word, it has the same meaning every time it occurs; while an index is essentially an affair of here and now. A word is the same word every time it occurs and if it has any meaning has always the same meaning; but this and that have different applications every time they occur.

1894 [c.] | The Art of Reasoning. Chapter II. What is a Sign? | EP 2:9

The word symbol has so many meanings that it would be an injury to the language to add a new one. I do not think that the signification I attach to it, that of a conventional sign, or one depending upon habit (acquired or inborn), is so much a new meaning as a return to the original meaning. [—]

The symbol is connected with its object by virtue of the idea of the symbol-using mind, without which no such connection would exist.

1895 | Short Logic: Chapter I. Of Reasoning in General | EP 2:17

A symbol is a sign naturally fit to declare that the set of objects which is denoted by whatever set of indices may be in certain ways attached to it is represented by an icon associated with it.

1898 | On Existential Graphs | MS [R] 484:5-7

Now what is a symbol? An icon represents its object as a mere dream, sufficient for itself. An index represents its object as an active, existent, thing, that insists on making me its other. A symbol represents its object as a manifestation, as a representamen having on the one hand a capacity of being indicated and on the other hand a capacity of being iconized. The object not only exists but has a regularity, a general nature, a reason. It has parts, aspects, continuity, bounds. All signs are more or less symbolic. Take a picture, for example. Here are a lot of colors doubled on a canvas. But I know that they are intended to represent something unlike the canvass in having three dimensions, and the colors represent quite different colors in the object, to which they are proportionate by a scale of values. This is one of the reasons why I must be a connoisseur in order to judge of a painting. The object represented may not exist in the world of sense-experience; but it has an existence in the creation of the artist. It forces itself upon my apprehension much as an object of outward experience would do. Thus, the picture has an indexical nature, and as representing that its indicated object has steady and general characters it is symbolic. It represents its object as something which manifests, or represents, an occult Ding an sich behind it. Again, I am crossing the street rather abstractedly when I am startled by a sharp shout of “Hi!” It is difficult to imagine a sign more purely indexical, more exclusively calculated to rouse my attention to experience of the moment. Yet, after all, this cry has a meaning. I do not dodge as I might instinctively do if it were the whiz of a bullet. I instinctively jump forward, because the cry means that I should do so. Thus, a particular quality of the things about me is asserted in the explanation. Thus, every sign whatever is more or less symbolic. It recognizes its object as manifesting in some grade or manner of existence some general nature which may vary continuously, but not beyond more or less vaguely thought limits. It is a conventional or quasi-conventional sign, which represents its object as conforming to some general rule of representation. Beggars are said to make marks at the entrances of estates which not merely direct attention to those estates, but also classify the families which inhabit them. These marks are symbols.

1899-1900 [c.] | Notes on Topical Geometry | MS [R] 142:4-6

Signs are of three kinds,

1st, the icon, which represents its object by virtue of a character which it would equally possess did the object and the interpreting mind not exist;

2nd, the index, which represents its object by virtue of a character which it could not possess did the object not exist, but which it would equally possess did the interpreting mind not operate;

3rd, the symbol, which represents its object by virtue of a character which is conferred upon it by an operation of the mind.


A symbol is a sign which represents an object by virtue of having a character imputed to it by an operation of the interpreting mind.

1901-1902 [c.] | Definitions for Baldwin's Dictionary [R] | MS [R] 1147

A symbol is a representamen which refers only to such objects and in such respects as it might determine an interpretant to refer to those objects in those respects, and is hereby alone essentially a representamen, not in virtue of a physical relation or of an agreement of characters, but by a relation subsisting only by virtue of a representation. There must, therefore, be some general rule which connects the symbol with its objects; and it represents whatever that general rule determines it to represent.

1902 | Sign | DPP2, 527; CP 2.304

A symbol is a sign which would lose the character which renders it a sign if there were no interpretant. Such is any utterance of speech which signifies what it does only by virtue of its being understood to have that signification.

1902 | Symbol | DPP2, 640; CP 2.307

Symbol. A Sign (q.v.) which is constituted a sign merely or mainly by the fact that it is used and understood as such, whether the habit is natural or conventional, and without regard to the motives which originally governed its selection.

1902 | Minute Logic: Chapter I. Intended Characters of this Treatise | CP 2.92

A Genuine Sign is a Transuasional Sign, or Symbol, which is a sign which owes its significant virtue to a character which can only be realized by the aid of its Interpretant. Any utterance of speech is an example. If the sounds were originally in part iconic, in part indexical, those characters have long since lost their importance. The words only stand for the objects they do, and signify the qualities they do, because they will determine, in the mind of the auditor, corresponding signs.

1902 | Minute Logic: Chapter I. Intended Characters of this Treatise | MS [R] 425:116-117

…signs must be divided, first, into those which are signs by virtue of facts which be equally true even if their objects and interpretants were away and even non-existent, which are likenesses, or Icons; second, into those which are signs by virtue of facts which would subsist even if their interpretants were away, though not if their objects were away, which are indications, or Indices; and thirdly, into signs which are signs only by virtue of facts which would cease to be true if their interpretants were removed, which are intellectual signs, or Symbols.

1902 [c.] | Reason's Rules | MS [R] 599:43

A Symbol […] represents its object solely by virtue of being represented to represent it by the interpretant which it determines.

1903 | Harvard Lectures on Pragmatism: Lecture III | CP 5.73

A symbol is a representamen which fulfills its function regardless of any similarity or analogy with its object and equally regardless of any factual connection therewith, but solely and simply because it will be interpreted to be a representamen. Such for example is any general word, sentence, or book.

1903 | Lecture I [R] | MS [R] 450:6

A conventional sign has since Aristotle and earlier received the name of symbol; but besides conventional symbols there are signs of the same nature except that instead of being based on express conventions they depend on natural dispositions. They are natural symbols. All thought takes place by means of natural symbols and of conventional symbols that have become naturalized. A symbol is employed over and over again, and we call all the occurrences of it occurrences of the same symbol. That is to say, it is the general type that makes the symbol, or its being made according to certain general precepts.

1903 | C.S.P.'s Lowell Lectures of 1903 2nd Draught of 3rd Lecture | MS [R] 462:88

The third class of signs are Symbols, which not only, like all signs, function as such in being interpreted as such, but further have for their special significant character merely the certainty, based on some habit, natural disposition, or convention, that they will be understood in certain ways.

1903 | Syllabus: Syllabus of a course of Lectures at the Lowell Institute beginning 1903, Nov. 23. On Some Topics of Logic | EP 2:274

A Symbol is a Representamen whose Representative character consists precisely in its being a rule that will determine its Interpretant. All words, sentences, books, and other conventional signs are Symbols. We speak of writing or pronouncing the word “man”; but it is only a replica, or embodiment of the word, that is pronounced or written. The word itself has no existence although it has a real being, consisting in the fact that existents will conform to it. It is a general mode of succession of three sounds or representamens of sounds, which becomes a sign only in the fact that a habit, or acquired law, will cause replicas of it to be interpreted as meaning a man or men. The word and its meaning are both general rules; but the word alone of the two prescribes the qualities of its replicas in themselves. Otherwise the “word” and its “meaning” do not differ, unless some special sense be attached to “meaning.”

A Symbol is a law, or regularity of the indefinite future. Its Interpretant must be of the same description; and so must be also the complete immediate Object, or meaning. But a law necessarily governs, or “is embodied in” individuals, and prescribes some of their qualities. Consequently, a constituent of a Symbol may be an Index, and a constituent may be an Icon.

1903 | Syllabus: Nomenclature and Division of Triadic Relations, as far as they are determined | EP 2:292

A Symbol is a sign which refers to the Object that it denotes by virtue of a law, usually an association of general ideas, which operates to cause the Symbol to be interpreted as referring to that Object. It is thus itself a general type or law, that is, is a legisign. As such it acts through a replica. Not only is it general itself, but the Object to which it refers is of a general nature. Now that which is general has its being in the instances which it will determine. There must, therefore, be existent instances of what the symbol denotes, although we must here understand by “existent,” existent in the possibly imaginary universe to which the symbol refers. The symbol will indirectly, through the association or other law, be affected by those instances; and thus the symbol will involve a sort of index, although an index of a peculiar kind. It will not, however, be by any means true that the slight effect upon the symbol of those instances accounts for the significant character of the symbol.

1903 [c.] | Logical Tracts. No. 1. On Existential Graphs | MS [R] 491:6-7

A symbol is a representamen whose representative force depends on how it is interpreted.
This sounds like nonsense; for what else is the interpretative force of a representation but its interpretation? But an example will at once show what is meant. The word “man” has the meaning it has simply by virtue of there being a general law, or habit, among English speaking interpreters, to which the interpretations of it will conform. Not only is “man” a “general sign” formaliter, or in its signification, but it is also general materialiter, in its mode of being as a sign. It is certainly not an existent individual. [—] Still less is it an appearance, flitting through the mind, and gone forever. It is evidently of the nature of a habit; not in the physiological sense (if there be any), but in the sense of a law to which not merely all interpretations so far have conformed but to which coming interpretations are really influenced to conform. In short, it is a real general. All modern philosophers teach that generals are “mere” words, or “mere” conceptions, or “mere” symbols of some kind; although they are quite beyond comparison the most important things there are. However this may be, if generals are symbols, no doubt symbols are all generals.

1903 [c.] | Logical Tracts. No. 2. On Existential Graphs, Euler's Diagrams, and Logical Algebra | CP 4.447

A symbol is a representamen whose special significance or fitness to represent just what it does represent lies in nothing but the very fact of there being a habit, disposition, or other effective general rule that it will be so interpreted. Take, for example, the word “man.” These three letters are not in the least like a man; nor is the sound with which they are associated. Neither is the word existentially connected with any man as an index. It cannot be so, since the word is not an existence at all. The word does not consist of three films of ink. If the word “man” occurs hundreds of times in a book of which myriads of copies are printed, all those millions of triplets of patches of ink are embodiments of one and the same word. I call each of those embodiments a replica of the symbol. This shows that the word is not a thing. What is its nature? It consists in the really working general rule that three such patches seen by a person who knows English will effect his conduct and thoughts according to a rule.

1903 [c.] | Logical Tracts. No. 2. On Existential Graphs, Euler's Diagrams, and Logical Algebra | CP 4.464

Every symbol is an ens rationis, because it consists in a habit, in a regularity; now every regularity consists in the future conditional occurrence of facts not themselves that regularity.

1903 [c.] | P of L | MS [R] 800:4

symbols, of which these characters that make them refer to their proper objects consist in laws or habits by virtue of which they will, under suitable conditions, be interpreted as referring to those objects.

1904 | Letters to Lady Welby | SS 33

I define a Symbol as a sign which is determined by its dynamic object only in the sense that it will be so interpreted. It thus depends either upon a convention, a habit, or a natural disposition of its interpretant, or of the field of its interpretant (that of which the interpretant is a determination).

1904 | On the Foundations of Mathematics | MS [R] 7:17

A third kind of sign, which brings the reference to an interpretant into prominence[,] is one which is fit to be a sign, not at all because of any particular analogy with the qualities that it signifies, nor because it stands in any reactive relation with its object, but simply and solely because it will be interpreted to be a sign. I call such a sign a symbol.

1904 | Firstness, Secondness, Thirdness, and the Reducibility of Fourthness [R] | MS [R] 914:7

…a sign may, in its secondness to the object as represented, [—] either, as an ‘Icon,’ be related to that object by virtue of a character which belongs to the sign in its own firstness, and which equally would belong to it though the object did not exist, or, as an ‘Index,’ [it] may be related to the object by a real secondness, such as a physical connection […] to it, or it may, as a ‘Symbol,’ be related to its object only because it will be represented in its interpretant as so related, as is the case with any word or other conventional sign, or any general type of image regarded as a schema of a concept.

1904 [c.] | New Elements (Kaina stoiceia) | EP 2:307

A symbol is defined as a sign which is fit to serve as such simply because it will be so interpreted.

[—] A symbol is a sign fit to be used as such because it determines the interpretant sign.

1904 [c.] | New Elements (Kaina stoiceia) | EP 2:317

A symbol is defined as a sign which becomes such by virtue of the fact that it is interpreted as such. The signification of a complex symbol is determined by certain rules of syntax which are part of its meaning. A simple symbol is interpreted to signify what it does from some accidental circumstance or series of circumstances, which the history of any word illustrates. [–] A symbol is adapted to fulfill the function of a sign simply by the fact that it does fulfill it; that is, that it is so understood. It is, therefore, what it is understood to be. [—] Hardly any symbol directly signifies the characters it signifies; for whatever it signifies it signifies by its power of determining another sign signifying the same character.

1904 [c.] | New Elements (Kaina stoiceia) | EP 2:322-4

…the most characteristic aspect of a symbol is its aspect as related to its interpretant; because a symbol is distinguished as a sign which becomes such by virtue of determining its interpretant. An interpretant of a symbol is an outgrowth of the symbol.


A symbol is essentially a purpose, that is to say, is a representation that seeks to make itself definite, or seeks to produce an interpretant more definite than itself. For its whole signification consists in its determining an interpretant; so that it is from its interpretant that it derives the actuality of its signification.


A symbol is an embryonic reality endowed with power of growth into the very truth, the very entelechy of reality. This appears mystical and mysterious simply because we insist on remaining blind to what is plain, that there can be no reality which has not the life of a symbol.

1905 | Notes on Portions of Hume's "Treatise on Human Nature" | MS [R] 939:26

by a symbol I mean a sign which represents its object only by virtue of the fact that it will be interpreted as doing so.

1905 | Notes on Portions of Hume's "Treatise on Human Nature" | MS [R] 939:45-7

In their relation to their Dyadic Objects, Signs are, 1st, those which refer to their objects by virtue of their independent possession of some character of those objects, as a figure of a triangle used in a geometrical demonstration represents any triangle, because it has three rectilinear sides, which it would have, just the same, even if it were not considered as a sign and if there were no other possible triangle in the world for it to represent; 2nd, those signs which refer to their objects by virtue of being really related to them in existence, as a thermometer is a sign of the temperature of its environment; 3rd, those signs which refer to their objects not as resembling them, nor as being in fact actually connected with them, but simply by virtue of the circumstance that they will be interpreted as referring to those objects. I term these three kinds, Icon, Index, Symbol. [—] [A] Symbol can only be a Legisign. It cannot be either a Qualisign or a Sinsign. For a Symbol is founded on a general convention, general habit, or general disposition to interpret it in a certain way. Now this general convention, habit, or disposition can only refer to a general description of sign.

1905 | Letters to Mario Calderoni | MS [R] L67:38-39

Symbols, or those signs which represent their objects simply because they will be interpreted to refer to those objects

1906 | Prolegomena to an Apology for Pragmaticism | CP 4.531

… an analysis of the essence of a sign, (stretching that word to its widest limits, as anything which, being determined by an object, determines an interpretation to determination, through it, by the same object), leads to a proof that every sign is determined by its object, either first, by partaking in the characters of the object, when I call the sign an Icon; secondly, by being really and in its individual existence connected with the individual object, when I call the sign an Index; thirdly, by more or less approximate certainty that it will be interpreted as denoting the object, in consequence of a habit (which term I use as including a natural disposition), when I call the sign a Symbol. [—] A Symbol incorporates a habit, and is indispensable to the application of any intellectual habit, at least. Moreover, Symbols afford the means of thinking about thoughts in ways in which we could not otherwise think of them. They enable us, for example, to create Abstractions, without which we should lack a great engine of discovery. These enable us to count; they teach us that collections are individuals (individual = individual object), and in many respects they are the very warp of reason. But since symbols rest exclusively on habits already definitely formed but not furnishing any observation even of themselves, and since knowledge is habit, they do not enable us to add to our knowledge even so much as a necessary consequent, unless by means of a definite preformed habit.

1908 [c.] | A Neglected Argument for the Reality of God (G) | MS [R] 842:33-34

[Symbols are] signs which represent their objects simply because they will be so understood, or arbitrary signs. [—] The denotation of a symbol is always definitely general, that is it stands for any object its interpreter may choose provided it be of a certain description, and not merely for some unspecified object of that description which its utterer may have in mind.

1909 | A Sketch of Logical Critics | EP 2:460-461

… I had observed that the most frequently useful division of signs is by trichotomy into firstly Likenesses, or, as I prefer to say, Icons, which serve to represent their objects only in so far as they resemble them in themselves; secondly, Indices, which represent their objects independently of any resemblance to them, only by virtue of real connections with them, and thirdly Symbols, which represent their objects, independently alike of any resemblance or any real connection, because dispositions or factitious habits of their interpreters insure their being so understood.

1909 | Meaning Preface | MS [R] 637:33-34

…the mode of representation may be by likeness or analogy, in which case, the sign may be called an Icon; or it may be by a real connexion, as a certain kind of rapid pulse is symptom of a fever, in which case the sign may be called an indication or Index; or finally the only connexion may lie in the fact that the Sign (a word, for example) is sure to be interpreted as standing for the Object, in which case the Sign may be called a Symbol

1909.10.06 | Meaning Preface | MS [R] 638:20-21; ILS 251

The word “Symbol” will in this book be used as the common name for that class of Signs which represent, to those that can interpret them, the objects they do quite regardless of any resemblances to them (although such may have influenced the original choice of the signs), and equally so of any actual connexions therewith, (however close such connexions there may be,) but solely because those interpreters have habits of mind, whether inherited or acquired, that lead them whenever they perceive the signs straightway to think of those Objects.