Key theories 2: Pierce

At around the same time as Saussure, independent work was also in progress as the pragmatist philosopher and logician Charles Sanders Peirce formulated his own model of the sign: semiotics and the taxonomies (classification) of signs. He held that "all this universe is perfused with signs, if it is not composed exclusively of signs".

In contrast to Saussure's dyadic model of the sign, Peirce offered a triadic model with three semiotiv elements as follows: -

1. Sign (or representamen): that which represents the denoted object (cf. Saussure's "signifier").
2. Object (or semiotic object): that which the sign represents (or as some put it, encodes). It can be anything thinkable, a law, a fact, or even a possibility (a semiotic object could even be fictional, such as Hamlet);
3. Interpretant (or interpretant sign): a sign's meaning or ramification as formed into a further sign by interpreting (or, as some put it, decoding) the sign. The interpretant may be:
   1. immediate to the sign, a kind of possibility, all that the sign is suited to immediately express, for instance a word's usual meaning;
   2. dynamic, that is, the meaning as formed into an actual effect, for example an individual translation or a state of agitation, or final or normal, that is, the ultimate meaning. It is a kind of norm or ideal end, with which an actual interpretant may, at most, coincide.

Pierce stated: 'A sign... [in the form of a representamen] is something which stands to somebody for something in some respect or capacity. It creates in the mind of that person an equivalent sign, or perhaps a more developed sign. That sign which it creates I call the interpretant of the first sign. The sign stands for something, its object. It stands for that object, not in all respects, but in reference to a sort of idea, which I have sometimes called the ground of the representamen' 

The interaction between the representamen, the object and the interpretant is referred to by Peirce as 'semiosis'. Within Peirce's model of the sign, the traffic light sign for 'stop' would consist of: a red light facing traffic at a junction (the representamen); vehicles halting (the object) and the idea that a red light indicates that vehicles must stop (the interpretant). 

Peirce's model of the sign includes an object or referent - which does not, of course, feature directly in Saussure's model. The representamen is similar in meaning to Saussure's signifier whilst the interpretant is similar in meaning to the signified’. However, the interpretant has a quality unlike that of the signified: it is itself a sign in the mind of the interpreter. Umberto Eco uses the phrase 'unlimited semiosis' to refer to the way in which this could lead (as Peirce was well aware) to a series of successive interpretants (potentially) ad infinitum’. Elsewhere Peirce added that 'the meaning of a representation can be nothing but a representation'.  Any initial interpretation can be re-interpreted. That a signified can itself play the role of a signifier is familiar to anyone who uses a dictionary and finds themselves going beyond the original definition to look up yet another word which it employs. 

According to Peirce, signs can be divided by the type of relation that holds the sign relation together. These are either icons, indices or symbols: -

1. Symbol/symbolic: a mode in which the signifier does not resemble the signified but which is fundamentally arbitrary or purely conventional - so that the relationship must be learnt: e.g. language in general (plus specific languages, alphabetical letters, punctuation marks, words, phrases and sentences), numbers, morse code, traffic lights, national flags; 
2. Icon/iconic: a mode in which the signifier is perceived as resemblingor imitating the signified (recognisably looking, sounding, feeling, tasting or smelling like it) - being similar in possessing some of its qualities: e.g. a portrait, a cartoon, a scale-model, onomatopoeia, metaphors;
3. Index/indexical: a mode in which the signifier is not arbitrary but is directly connected in some way (physically or causally) to the signified - this link can be observed or inferred: e.g. 'natural signs' (smoke, thunder, footprints, echoes, non-synthetic odours and flavours), medical symptoms and indexical words ('that', 'this', 'here', 'there').

The three forms are listed here in decreasing order of conventionality. Symbolic signs such as language are highly conventional; iconic signs always involve some degree of conventionality; indexical signs 'direct the attention to their objects by blind compulsion'. Indexical and iconic signifiers can be seen as more constrained by referential signifieds whereas in the more conventional symbolic signs the signified can be seen as being defined to a greater extent by the signifier. Within each form signs also vary in their degree of conventionality.

It is easy to slip into referring to Peirce's three forms as 'types of signs', but they are not necessarily mutually exclusive: a sign can be an icon, a symbol and an index, or any combination. Peirce was aware of this: he insisted that 'it would be difficult if not impossible to instance an absolutely pure index, or to find any sign absolutely devoid of the indexical quality'. A map is indexical in pointing to the locations of things, iconic in its representation of the directional relations and distances between landmarks and symbolic in using conventional symbols the significance of which must be learnt. The film theorist Peter Wollen argues that 'the great merit of Peirce's analysis of signs is that he did not see the different aspects as mutually exclusive. Unlike Saussure, he did not show any particular prejudice in favour of one or the other.

Hawkes notes, following Jakobson, that the three modes 'co-exist in the form of a hierarchy in which one of them will inevitably have dominance over the other two', with dominance determined by context. Whether a sign is symbolic, iconic or indexical depends primarily on the way in which the sign is used.

Peirce's theory of the sign therefore offered a powerful analysis of the signification system, its codes, and its processes of inference and learning, This was because the focus was often on natural or cultural context rather than linguistics, which only analyses usage in slow time; whereas human semiotic interaction in the real world often has a chaotic blur of language and signal exchange.