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Peirce's Semiotics

By Nicole Everaert-Desmedt

Professor, Facultés universitaires Saint-Louis, Brussels

1. Abstract


Charles Sanders Peirce

We will present Charles Sanders Peirce's three philosophical categories, and then explain how these categories operate at various levels in the process of semiosis, or sign functioning. The process of semiosis is a triadic relationship between a sign or representamen (a first), an object (a second) and an interpretant (a third). Each of these three terms is in turn broken down following the three categories. From this structure, by observing the hierarchy of categories, ten mechanisms of signification may be identified.

This text may be reproduced for non-commercial purposes, provided the complete reference is given:
Nicole Everaert-Desmedt (2011), « Peirce's Semiotics », in Louis Hébert (dir.), Signo [online], Rimouski (Quebec),



Peirce developed a semiotic theory that is at once general, triadic and pragmatic1.

It is general:

  • in that it takes into consideration emotional, practical and intellectual experience;
  • it includes all of the components of semiotics;
  • it broadens the concept of the sign.

It is triadic:

  • in that it is founded upon three philosophical categories: firstness, secondness and thirdness;
  • it brings three terms into relation: the sign or representamen, the object and the interpretant.

It is pragmatic:

  • in that it takes into consideration the context in which signs are produced and interpreted;
  • it defines the sign by its effect on the interpreter.


According to Peirce, three categories are necessary and sufficient to account for all of human experience. These categories correspond to the numbers first, second and third. They have been designated as "firstness", "secondness", and "thirdness".


Firstness is a conception of being that is independent of anything else. For example, this would be the mode of being of a "redness" before anything in the universe was yet red, or of a general sensation of hurt, before one starts to wonder whether the sensation comes from a headache, a burn or some emotional pain. We must be clear that in firstness, there is only ONENESS. Thus, it is a conception of being in its wholeness or completeness, with no boundaries or parts, and no cause or effect. A quality is a pure, latent potentiality. Firstness belongs to the realm of possibility; it is experienced within a kind of timelessness. Firstness corresponds to emotional experience.


Secondness is the mode of being that is in relation to something else. This is the category that includes the individual, experience, fact, existence, and action-reaction. For example, the stone that we drop falls to the ground; the weathervane turns to point in the direction of the wind; and now you feel pain because of a toothache. Secondness operates within discontinuous time, where the dimension of past time enters in: a certain event occurred at a certain moment, before some other event, which was its consequence. Secondness corresponds to practical experience.


Thirdness is the mediator through which a first and a second are brought into relation. Thirdness belongs to the domain of rules and laws; however, a law can only be manifested through the occurrences of its application, that is, by secondness; and these occurrences themselves actualize qualities, and therefore, firstness. Whereas secondness is a category of individuality, thirdness and firstness are categories of generality; but the generality of firstness is on the level of possibility, and the generality of thirdness is on the level of necessity, and therefore, prediction. The law of gravity, for example, allows us to predict that each time we drop a stone, it will fall to the ground. Thirdness is the category of thought, language, representation, and the process of semiosis; it makes social communication possible. Thirdness corresponds to intellectual experience.


According to Peirce, a sign may be simple or complex. Unlike Saussure, Peirce does not define the sign as the smallest unit of signification. Any thing or phenomenon, no matter how complex, may be considered as a sign from the moment it enters into a process of semiosis.

The process of semiosis involves a triadic relationship between a sign or representamen (a first), an object (a second) and an interpretant (a third).

The representamen is a thing that represents another thing: its object. Before it is interpreted, the representamen is a pure potentiality: a first.

The object is what the sign represents. The sign can only represent the object; it cannot furnish acquaintance with it. The sign can express something about the object, providing that it is an object with which the interpreter is already familiar from collateral observation (experience created from other signs, which are always from previous history). For example, a piece of red paper that is used as a sample (= representamen) for a can of paint (= object) indicates only the red colour of the object, since it is assumed that one already knows all of its other characteristics (packaging, content, usage, etc.). The piece of paper shows that the paint in the can is red in colour, but it says nothing about the other characteristics of the object. Furthermore, if the interpreter knows that it refers to a can of paint, then, and only then, does the sample give him the information that this particular can of paint must be red. To put it more succinctly, Peirce distinguishes the dynamical object (the object as it is in reality) from the immediate object (the object as it is represented by the sign). In our example, the can of paint is the dynamical object, and the colour red (of the can of paint) is the immediate object.

Upon being interpreted, the representamen has the ability to trigger an interpretant, which in turn becomes a representamen by triggering another interpretant referring to the same object as the first representamen, and thereby allowing the first one to refer to the object. And so on, ad infinitum. For example, the definition of a word in the dictionary is an interpretant of the word, because the definition refers to the object (= what the word represents) and thereby allows the representamen (= the word) to refer to this object. But in order to be understood, the definition itself requires a series, or more accurately, a bundle of other interpretants (other definitions)... Thus, the process of semiosis is theoretically unlimited. We are engaged in a thought process that is always incomplete, that has always begun previously.


The process of semiosis is theoretically unlimited. However, it is limited in practice, being short-circuited by force of habit, which Peirce calls the final logical interpretant - our habit of attributing a certain signification to a certain sign in a certain context with which we are familiar. Force of habit temporarily freezes the infinite recursivity of one sign to other signs, which allows interlocutors to quickly reach consensus on reality in a given communication context. But habit is formed by the effect of previous signs. Signs are the catalysts that cause habits to be reinforced or changed.

Peirce's view of semiosis integrates all the components of semiotics: Pragmatics (the domain of the interpretant) is inseparable from semantics (the domain of the object) and from syntax (the domain of the representamen).


Each of the three terms of semiosis is further subdivided following the three categories: thus, we distinguish firstness, secondness and thirdness in the representamen, in representamen-object relations, and in the way the interpretant implements the relationship between representamen and object.


The representamen can be (1) a qualisign (firstness), meaning a quality that functions like a sign; (2) a sinsign (secondness), meaning a specific spatio-temporal thing or event that functions like a sign; or (3) a legisign (thirdness), meaning a conventional sign.

Examples of legisigns are passwords, insignias, tickets for a show, traffic signals, and the words of a language. However, legisigns cannot act until embodied as sinsigns, which are "replicas". For instance, the article "the" is a legisign in the English language system. But it can only be used within the medium of the voice or the text that embodies it. It is embodied in sinsigns (its occurrences, occupying different spatio-temporal positions), but also includes qualisigns, such as the intonation of the oral replica, or the shape of the letters of the written replica.


A representamen can refer to its object by virtue of firstness, secondness or thirdness, that is, through relationships of similarity, contextual contiguity or law. Following this trichotomy, the sign is called (1) an icon, (2) an index or (3) a symbol, respectively.

The reference between a sign and its object is iconic if the sign resembles the object. An icon may have as its representamen a qualisign, a sinsign or legisign. For example, the feeling (qualisign) produced by playing a piece of music is the icon of that piece of music. Someone's portrait (sinsign) is the icon of that person, and a model (sinsign) is the icon of a building. A drawing of a glass (sinsign) is the icon of a glass, but if it is placed on a crate, then it belongs to the pictogram code and becomes a replica of the legisign signifying 'fragile' through iconic portrayal of a species (a glass) that is part of a genera (fragile objects).

The reference between a sign and its object is indexical if the sign really is affected by the object. For example, the position of a weathervane is caused by the direction of the wind; it is the index of the wind direction. A knock on the door is the index of a visit. The symptom of an illness is the index of that illness. An index cannot have a qualisign as its representamen, because there is only "sameness" in firstness, and no contextual contiguity; therefore, a qualisign is always iconic (refer to the hierarchy of categories below). An index may have as its representamen a sinsign, as in the examples above, or a legisign, as in certain words known as "indexical" words ("this", "that", "I", "here").

A sign is a symbol when it refers to its object by virtue of a law. Passwords, tickets to a show, banknotes, and the words of a language are symbols. The symbolic rule may have been formulated a priori by convention, or a posteriori by cultural habit. A symbol's representamen is necessarily a legisign, but the legisign cannot really act until it is embodied in a replica, and from that point on, the symbol implies an index. For example, in the traffic code, the red light in the abstract is a symbolic legisign, but each one of its replicas is an indexical sinsign.


In the sign trichotomy of the interpretant, the sign is called (1) a rheme (firstness), (2) a dicisign or dicent sign (secondness) or (3) an argument or reasoning (thirdness).

The rhematic interpretant has a firstness structure: thus in implementing the relationship between the representamen and object, it does not refer to anything "else" but the qualities of the representamen, which are also the qualities of a whole class of possible objects. The rheme is neither true nor false; it is equivalent to a variable in a functional proposition. It functions like a form with blanks to be filled in or a space on a questionnaire: "......... is red". For instance, a person's portrait, with no other indications, represents a whole class of possible objects: the people who look like the portrait. This is a rhematic iconic sinsign. But if the portrait is considered in a context where it is accompanied by something indicating the person's name, for example on a passport, then the level of interpretation changes: now we are dealing with secondness (a dicent indexical sinsign). The hierarchy of categories (see below) produces six classes of rhematic signs.

The dicisign is a sign interpreted at the level of secondness; it functions like a logical proposition, which establishes a relationship between constants (a subject (what we are talking about) and a predicate (what we say about it)) and it is either true or false. For example, a person's portrait with an indication of his/her name is a dicent indexical sinsign. The interpretant of this sign would be the proposition that "the person shown in this picture is Mr. So-and-So". Later we will see that by virtue of the hierarchy of categories, there are three classes of dicent signs. As we have said, a dicisign is true or false, in contrast to a rheme, which represents a possibility and has no truth value. But a dicisign does not furnish reasons for being true or false, in contrast to an argument, which arrives at a conclusion by following a rational process.

The argument is a sign interpreted at the level of thirdness; it formulates the rule joining the representamen to its object. An argument always has a legisign as its representamen and a symbol as its object. However, three kinds of arguments may be distinguished depending on the nature of the rule that binds the representamen to its object. The rule may be (1) imposed on the facts (deduction: "Every time there is a red light, there is an order to stop"; (2) a result of the facts (induction: "Wherever there is smoke, there is fire"); or (3) the argument may consist of formulating a rule in the form of a hypothesis that would explain a fact (abduction). Peirce gives this example of abduction: Imagine that upon entering a room, I see a table with a handful of white beans on it, and next to it, a bag of beans. I observe that this bag contains only white beans. I then formulate the hypothesis that the beans on the table came from this bag. Abduction is an argument that appeals to firstness in order to formulate the rule (it is a hypothesis, and therefore a possible rule), whereas induction is based on secondness (the rule follows from repeated observation of actual, contingent facts), and deduction falls exclusively under thirdness (as a rule, it justifies itself).


Deduction and induction were studied in depth by the classical philosophers, but no logician before Peirce had recognized the importance or the specific character of this third form of reasoning, which Peirce called abduction. Nonetheless, it is a form of reasoning that happens to be used in the most mundane circumstances as well as in scientific research, and on this point, Peirce anticipates Karl Popper's epistemology.

The interpretive process of abduction (or process of deductive hypothesis) can be described in four stages:

1. We encounter a curious fact that is unexplainable according to our previous knowledge; in other words, this fact startles us in our daily habits and prejudices. In the case of scientific research, the fact is not accounted for by any existing theory.

2. We formulate a hypothesis that may explain the fact. Our reasoning is grounded in firstness, in that the hypothesis, which springs to mind with instinctive force, is suggested by the fact. Indeed, there is an analogy between the fact and the possible consequences of applying the hypothesis.

3. Next we apply the hypothesis deductively, and we infer the consequences that follow from it. We adopt an attitude in life that matches the hypothesis. In scientific research, this is a matter of rigorously determining which tests might allow us to disprove the hypothesis if need be (to prove it is false or does not match the facts). While a single experiment can invalidate a hypothesis, it would take an infinite series of experiments to confirm it.

4. By using a kind of induction, or making generalizations based on a number of positive test results, we conclude that the results verify the hypothesis, at least provisionally, until there is proof to the contrary.

Take an example of abduction from everyday conversation:

1. The startling event: Someone says, "It's cold in here", when the conversation had nothing to do with air temperatures. Let us say that we are in a room with an open window, that I am the listener, and am near the open window.

2. The explanatory hypothesis: I refer to a rule that is part of the commonly shared store of knowledge about things cultural and practical. It is less cold in a room when the window is closed. I have already been in similar situations, and when a room is judged to be cold, one closes the window. Immediately I establish a connection between my previous knowledge and what the speaker actually said, and come up with the hypothesis that the speaker would like me to close the window.

3. Deduction: I take the consequence of the hypothesis as a prediction, and I act accordingly: I close the window.

4. Induction: The speaker makes no objection when I close the window; in fact he thanks me. This result confirms my hypothesis.


Firstness includes nothing other than itself, whereas secondness includes firstness, and thirdness includes both secondness and firstness. For this reason, in semiosis there exists a principle of hierarchy among the categories, and by this principle a representamen (a first) cannot refer to an object (a second) from a higher category; as for the interpretant (a third), it cannot belong to a category higher than its object's. For example, a sinsign (the category 2 representamen) cannot be a symbol (the category 3 object), but it can be considered as an icon (the category 1 object) or an index (the category 2 object). By adhering to the hierarchy of categories, we can construct ten mechanisms of signification, shown below, with an example for each case. (R, O and I indicate the representamen, the object and the interpretant, respectively):

The ten classes of sign functioning





1 1 1

rhematic iconic qualisign a general vague of hurt.


2 1 1

rhematic iconic sinsign: a model.


2 2 1

rhematic indexical sinsign: an involuntary shout.


2 2 2

dicent indexical sinsign: a weathervane.


3 1 1

rhematic iconic legisign: onomatopoeia: "cock-a-doodle-doo".


3 2 1

rhematic indexical legisign: an indexical word: "that".


3 2 2

dicent indexical legisign: a red light in context2.


3 3 1

rhematic symbolic legisign: a common noun: "apple"


3 3 2

dicent symbolic legisign: a proposition: "it's cold in here".


3 3 3

argument symbolic legisign:

  1. abduction: "It's cold in here" interpreted as a request to close the window.
  2. induction: "Where there is smoke there is fire".
  3. deduction: the red light of the traffic code in the abstract.

The above list does not represent classes of signs to which we can assign phenomena by labelling them, but rather different levels of interpretation to which we can submit a single phenomenon, as we will show in the following application.

The following diagram shows the distribution of categories in semiosis.

The distribution of categories
Peirce : The distribution of categories


Consider the following phenomenon: a footprint in the sand.

1. This is a phenomenon located in space (a sinsign) whose shape resembles a foot (icon). In it we recognize the pertinent qualities and features of any foot (rheme). This sort of interpretation is situated in the present moment.

2. We could possibly become absorbed in the timeless contemplation of this shape pressed into matter (rhematic iconic qualisign), and perhaps we could capture its emotional depth in a photograph.

3. It is more likely that we will consider the past, along with the context in which the phenomenon occurred: This print was actually caused by someone who came by here (index). Our interpretation relates to concrete facts: this footprint and a specific foot that made it (dicisign).

4. But now suppose a detective is on the trail of a killer: He recognizes this print as a replica of a model (legisign) that he obtained previously. What interests him is to find out the actual whereabouts of the person he is looking for, not just to observe that the person came by here. Therefore, the object to which the print refers is situated in the future. So for the detective, the print becomes a symbol showing what direction to take; because of the footprint, he can predict the direction he needs to go to continue his investigation. In order for the sign to function as a symbol, its iconic and indexical features must be perceived first, and then it must be seen as a replica of a model, which must appeal to an argument for interpretation. We have abduction: "This is a sign that the killer was here; we can postulate that whoever it was continued in this direction". Then the detective acts according to this hypothesis: He goes in the same direction.

Note that the detective's situation is different from that of a treasure hunt, where arrows are used as so many replicas of a legisign, which functions as a symbol of the direction to go according to a pre-established code. The arrows are interpreted by deduction, since the replicas were put there intentionally to show the way.


EVERAERT-DESMEDT, N., Le processus interprétatif. Introduction à la sémiotique de Ch.S. Peirce, Liège: Mardaga, 1990.
EVERAERT-DESMEDT, N., Interpréter l’art contemporain. La sémiotique peircienne appliquée aux œuvres de Magritte, Klein, Duras, Wenders, Chávez, Parant et Corillon, Bruxelles: De Boeck, 2006.


A. In the summary diagram, the representamen, the icon, the rheme and abduction are all elements of firstness. Explain why.
B. In the summary diagram, which terms come under secondness? Why?
C. In the summary diagram, which terms come under thirdness? Why?
D. Analyze the interpretive processes that might be triggered by the following signs:

1. A postage stamp or a banknote.
2. A pictogram indicating the bathrooms or the exit in a public place.
3. A passport, a desk calendar, a store sign, or a brand name.
4. A pen, a knife, a pair of glasses.
5. A building facade, a door, a window, a stairway.
6. A press photo, figurative paintwork, a monochromatic picture.

You can choose any object, simple or complex, but you must always interpret it in a specific context. (For example, the postage stamp in question has a certain picture and certain indications: it was cancelled on a certain postcard, and so forth).

1 Theoretical development and analysis examples can be found in Everaert-Desmedt, 1990 and 2006.

2 More exactly, we shall distinguish two levels: the red light in context is a replica (a dicent indexical sinsign) of the type ‘red light’ of the traffic code (a deductive symbolic legisign).

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