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Peirce’s Semeiotic

Scattered fragments

Peirce never wrote a treatise on semeiotic (also spelled semiotic, although Peirce seemed to prefer semeiotic in his late years). His ideas had to be collected from dozens of articles published throughout half a century of research, unpublished manuscripts found in notebooks and letters he exchanged about the subject. A compilation of texts from very different sources and periods shows – as might be expected when we talk about Peirce – a theory in constant development. There was not a single time in which, while working on his semeiotic, Peirce failed to introduce new terms and interpretations. Besides that, in his large philosophical architecture, semeiotic works like an amalgam capable of unifying several disciplines. It is mentioned and discussed in articles and letters about subjects as different as logic, mathematics and metaphysics. Peirce felt the obvious necessity of adapting the terminology and the notation according to the canons accepted by each of these sciences. As a result, charting the evolution of Peirce’s semeiotic demands knowledge in the various sciences it dialogues with, which could only be accomplish recently and yet in an incomplete way.

The initial question, which has produced a lot of controversy among Peircean scholars, is how we should picture the evolution of Peirce’s thought. Some, like Ransdell (1997), argues that Peirce maintained throughout his career the essence of the arguments presented for the first time in the articles published in the 1860’s. Murphey (1993, p.3), on the other hand, believes that Peirce’s philosophical architecture is similar to a house whose interior is being continuously remodeled, although preserving most of its structure. Short (2004) affirms that Peirce abandoned many of his juvenile ideas. Savan (1977, p. 179) goes further to say that Peirce’s mature Theory of Signs has little to do with his first formulation in 1860’s. It is necessary, thus, to know a little about how these changes may have happened.

The study of signs had been present in Peirce’s intellectual life since at least the mid-1860’s, when he was still a college student at Harvard. In 1865, at the age of 26, Peirce gave a series of conferences in Harvard about the logic of sciences wherein he demonstrated his mastery of Kant’s transcendental philosophy, the foundations of logic and the theory of probability, as well as the problem of representation – or how the ideas appear in the human mind. This last one is an important logical problem, for the truth of any proposition analyzed depends on it. Throughout his intellectual life, Peirce tried to study this matter under all the possible points of view. He extracted lessons from philosophical texts since antiquity, such as Plato and Aristotle, going through medieval ones up to his contemporaries of the 19th century.

The closest we have to a systematic exhibit of his Theory of Signs, made by Peirce’s own hands, is a brochure written to follow a series of lectures he gave at the Lowell Institute, in Cambridge, in October 1903, focused mainly on logic. This brochure is normally referred to as Syllabus among the scholars, many of whom consider it the most finished version of his semeiotic. In its pages appears the famous inverted triangle with ten genuine classes of signs created from three triadic divisions (or trichotomies). This is the classification found in most manuals and articles on Peircean semeiotic.

However, Peirce never considered the version published in the Syllabus the final word on the problem of classification of signs. As we will see shortly, the 1903 classification, although important, represented the beginning of a new round of creative revisions of his semeiotic, which went through the years of 1905 and 1906 and, actually, never ended. The number of trichotomies, which in the 1903 Syllabus was only three, from 1905 on came to be ten, with the daunting prospect that the classes of signs could be counted by the thousands. Between 1907 and 1909, Peirce had taken his semeiotic to such new directions in comparison with the past ones that the classification of the Syllabus was not even considered by him a starting point for his new classificatory exercises.

Synthesis of traditions

Peirce derived his conceptions of semeiotic as logic probably from the reading of the British empiricist philosophers. In fact, Locke had already affirmed in 1690 the necessity of a new type of logic, which he named Semeiotic, explaining that it should be a doctrine about the signs the mind makes use for the understanding of things. Still in the British tradition, Peirce received an influence from the logic of Mill, as well as from the writings of Hamilton. The empiric tradition usual to the British philosophers emphasized the importance of inductive inference and the related concepts of connotation (the predicable qualities of a term) and denotation (the things to which a term is applied) as fundamental to logic. The British logicians considered these two quantities essential for the study and classification of inferences and they played an important role in the formulation of Peirce’s semeiotic, mostly in its initial phases.

Nevertheless, Peirce already writes in his first articles that these two quantities could handle a central phenomenon in logic, which is the growth or evolution of the meaning of terms and propositions. For that reason, Peirce expands the logical dichotomy denotation/connotation introducing a third element: information. Information is an idealistic component launched in the interior of the empiricist logic and its introduction would have important consequences for the future of his theory of signs, mainly in his mature phase, when it embraced the reality of Thirdness. When semeiotic mixes up indissolubly with metaphysics, the concept of information will be the foundation of Peirce’s “idealistic realism”, also called objective idealism (Ibri, 1992, p. 55 and ss), which attests that universal forms are the agents that determine the reality of objects.

One has to remember indeed that one of Peirce’s greatest intellectual battles was to produce a philosophic synthesis that could extract the best from German and British traditions without losing sight of the latest scientific achievements. On the one hand, this concern drove him into scholastic philosophy, where he tried to find the roots of the two traditions he had striven to unify. From his reading of Occam and Scotus, for example, Peirce reached the doctrine of signs devised by the Stoics and, more importantly, the definition of  material implication accredited to Filo de Megara. On the other hand, this search for a philosophical synthesis made him read the greatest names of the German school, such as the transcendentalist Kant, the mathematical philosopher Leibniz and the idealists Hegel and Schelling.

Peirce’s philosophy also had an important naturalistic side, linked to his work as a geodesist and metrologist responsible for drawing and performing practical experiments, which also had strong influence in his semeiotic. In addition to all these influences, Peirce was also aware of the recent developments from the theory of evolution and impressed by the many advantages Mendeleev’s classification of chemical elements according to its valences and possibilities of connection had brought to chemistry. Peirce also studied intensively the zoologic classification performed by Agassiz, of whom he was a direct student in his youth. All this contact with empirical methods supplied ideas he would use and adapt when developing his semeiotic.

Soon Peirce concluded that science should start with a genuine effort to reveal and cast the natural classes given to direct observation – i.e. its starting point should be phenomenology. Having identified and defined the classes by their typology, science should then proceed to their proper classification, i.e. the arrangement of the natural classes according to their relations and affinity. This procedure should produce an architectonic classification of all the possible sciences (current and future), wherein the most abstract, as mathematics, should offer subsidies to the most empirical ones.

The primacy of mathematics in the classificatory construction of sciences, as well as its role as provider of premisses to the other sciences, instigated Peirce to maintain a restless research about the foundations of mathematics and its relation with other sciences, mostly with logic. For instance, his terminology about the three categories (firstness, secondness and thirdness) comes from mathematics. From his study about the relation between logic and mathematics, Peirce developed an algebraic logic independently from Frege. He also produced an axiomatization of natural numbers, and studied in detail the postulates and theorems of the Euclidian geometry, as well as the consequences of the new geometries proposed by Riemann and Lobatchevski. These studies also led him to research the notion of relation, infinity and continuity that he tried to apply to a special type of topology closely related to his semeiotic and his graphical logic.

In his first attempts to classify the sciences, logic appeared as a subordinate ramification of semeiotic. While the latter regards the signs in general, the former would be responsible for focusing its attention only on the symbols and the logic figures directly related to them, such as the term, the proposition and the argument (this last one also called syllogism or inference). That is why Peirce’s first important contribution to logic, made in the 1860’s, was the classification of the traditional Aristotelian syllogisms under the aegis of his three categories: the term is a first, the proposition, a second and the argument, a third. Later, however, Peirce started to consider semeiotic and logic as synonyms (Houser, 1992, – and a good part of his research was concentrated in the production of a definite classification for all the possible types of signs.

To this work of revealing typologies of signs and classifying them accordingly, Peirce gave the name of Speculative Grammar, which should be the first ramification of semeiotic. The second ramification is Critical Logic, considered by him as the science about the truth of representations, i.e. the study of the possibility of a sign to truly represent its object. Finally, Peirce conceived the Speculative Rhetoric (also methodeutics or communication) as the third ramification of semeiotic, defining it as the study of the effects produced by the action of the sign on its interpretants. Put in another way, Rhetoric is the study of how a “form” can be transmitted from the object to the interpretant, the sign being the vehicle of such transmission.

It is under the point of view of Rhetoric that semiosis (also spelled semeiosy and semeiosis) can be seen as communication oriented to a purpose. In his maturity, Peirce will emphasize that semiosis is not restricted to human minds but happens also in naturalized quasi-minds. It follows that communication is not necessarily intellectual, but can be considered an ontological process that produces the communion of minds of each person with the others and of all minds with the totality of a universal quasi-mind (cf. Murphey, 1993, p. 353).

In this page, we intend to aim at the evolution of Peirce’s semeiotic, but we cannot prevent from relating it to other fields of his philosophical interest such as cosmology and, especially, his pragmatism. After all, a good part of Peirce’s efforts to develop his sign theory, mostly after 1900, was due to his attempt at offering a strictly logical proof – or, at least, a philosophically consistent one – of his version of pragmatism, that he sometimes called pragmaticism. It is specially interesting to follow how semeiotic, although initially used by Peirce as an instrument of proof for his pragmatic method, grows slowly in importance to comprise the action of the sign in all possible instances of reality and not only in the clarification of concepts, as originally proposed by pragmatism (Houser, 1992, p. xxxv).

Let us see briefly how this evolution occurred.

First phase: 1867 to 1883 – The triadic sign and the denial of the Cartesian intuition

Peirce starts to develop his theory of Sign already in the first articles published by him, between 1867 and 1871. The first of them, which many scholars consider Peirce’s most important contribution to occidental philosophy, is “On a New List of Categories” (1867), referred to normally in the short form of New List. There Peirce revises the table of categories of both Aristotle and Kant, exposing for the first time his tripartite ontology. In the two following years (1868 and 1869), he publishes three other articles, today referred to by the experts as the “cognition series”. In these texts, he develops his concern about the origin of knowledge in our minds presenting an alternative for Cartesian gnosiology. Peirce strongly refutes the idea that knowledge is grounded on an artificial doubt, as it is in the case of the Cogito. Contrary to Descartes, he defends the idea that inquiry must begin with a genuine doubt, and that we must seek its answer not in getting rid of preconceptions but in trying to correct and refine them throughout the process of inquiry.

The dispute between nominalism and realism is the background of these texts. The controversy is a derivation of the old “question about the universals” that has divided philosophers since classical antiquity. It may be put this way: is an idea a mere creation of our minds in order to give sense to the multitude of impressions, or does this idea has a real being in the world and what we do is try to apprehend it the best we can with the limited powers of our intellect? Roughly speaking, whoever believes that the concepts are just names created by our minds to subsume the sense impressions is a nominalist. The realist, on the other hand, believes that general ideas, or universals, are in some way present in the reality, acting independently of whatever we may think of them. If nominalism is correct, Peirce argues, we are condemned to individualism, for each one of us will develop his own conceptions about the world; but if realism is correct, only the union of efforts of all intelligent minds may be able to form a true concept about reality. Nominalism leads to solipsism, but realism opens the doors to pragmatism as a method to clarify the ideas in the search for truth.

Actually, both nominalism and realism had many ramifications in the history of philosophy, including doctrines that proposed an intermediate position between the extremes. Peirce, probably on Kant’s track, was an assumed nominalist in his youth, but changed his mind and reached maturity proclaiming to be an extreme realist.

The fact that Peirce had abandoned nominalism does not mean that he had become anti-idealist, however. As noticed when we mentioned his concept of information, while Peirce should be considered a realist regarding logic, he also proclaimed to believe in a kind of objective idealism when he talked about metaphysics. That is why some commentators prefer to say that Peirce developed a sort of sui generis idealism-realism. The fact is that Peirce’s inaugural article is markedly Kantian and nominalist. In the New List, the element that condenses the knowledge about the world is the representation – a mental manifestation that bridges between the world and the intellect. It all starts, Peirce describes, with the synthesis of the senses impressions, where the mind creates ideas or general concepts through a process of comparison. Peirce proposes that two major groups divide the categories present a priori in the mind during this task: being and substance. While substance remains as something uncognizable, in the Kantian transcendental sense, being manifests itself to mind in the three ways that reflect the three possible types of comparison: quality (when related to a ground), relation (when related to a correlate) and finally representation (when related to an interpretant).

Afterwards, Peirce applies a similar trichotomy to representation, originating what he called at that time Resemblances (later Icons), Indexes and Symbols. The word representation, then, as used in the New List, equals what later Peirce would define as the genuine relation between sign, object and interpretant (S-O-I). There is, as we see, a triadic and indecomposable relation in the production of a sign: significance does not occur in the relation between the sign and its object only, as the majority of the previous theories of the signs affirmed, but it demands a third correlate. This new element is the interpretant, seen as the effect produced in the mind by the sign and, therefore, another sign. At this time, it must be clear, Peirce still saw representation as restricted to thought – a kind of internalized discourse inside the mind, based only on general concepts and very similar to the functioning of language (Short, 2004, p. 10).

In the three articles following the New List, dedicated specifically to the problem of cognition, Peirce eliminates the bipartition between being and substance, assuming the thesis that there is not such a thing as the Kantian uncognizable object, but everything can be learned by experience. The central purpose of these articles is to defend the idea that human cognition is a dynamic process that does start with an artificial doubt, as proposed by Descartes, but happens in media res. We should start the inquiry with our preconceptions or imperfect ideas and only slowly, by a continuous process of inferences, improve them in the direction of truth. Using hypotheses and their empirical tests against reality, we should be able to produce an argumentation not concatenated as a chain (that cannot be stronger than its weakest link), but woven like a cable made of thin and subtle fibers, provided they are so numerous and intimately connected to guarantee its strength.

For the 1860’s Peirce, the “train of thought” is a sequence of concepts without beginning or end. They all blend with each other the same way dots merge to create a line. A thought is a sign that represents a previous thought, which assumes the role of its object, and is interpreted by a subsequent thought, which assumes the role of its interpretant – and so on ad infinitum (Short, 2004, p.9). This mental semiosis assumes a fundamental role in the pragmatic search for truth, which is expected as the result of the whole process. Although this is an infinite series, semiosis does not have to drag out forever because the inferences occur at infinitesimal intervals, which are agglutinated through the schema of time. Peirce resorts to the paradox of Zeno describing the race between Achilles and the tortoise to show that the idea of an infinite series of interpretants does not imply endless semiosis. As much as Achilles will eventually reach the tortoise, the infinite series of inferences will produce a cognitive result.

In a review dedicated to the re-edition of the works of bishop George Berkeley (a well-known nominalist of the past), published in 1871, Peirce takes another step towards realism, although a type of realism still distant from the scholastic kind he would assume in the future. For example, the realism of this period still lacked a clear notion of secondness as the expression of a reality that exists outside mind and independent of what we think of it. This is precisely the role the index will take in the years to come. Although Peirce had already divided the sign in resemblances, indexes and symbols, they were still mental stuff. In addition, Peirce still held that the logician should consider only the types of representation derived from the symbol. Therefore, whatever is exterior to mind should not interest him/her.

This nominalist leftover lasted the whole 1870’s and influenced the foundational text on Pragmatism, How to Make Our Ideas Clear, published in 1877. According to Houser (2002), this article intended to show that the pragmatism was an improvement of the method of Descartes of classifying ideas through his test of clearness and distinction. This means that Peirce restricted his Pragmatism to a method to make clear concepts only, relating their meaning to the practical consequences implied in their acceptance. Peirce’s tendency to nominalism in this period is noticeable, for example, when he writes that nothing forbids us from affirming that “every hard body remains soft until we touch it” (EP1:132); i.e. he defends that the idea of hardness is something that exists in our minds and has nothing to do with the reality of things.

Second phase: 1883 to 1896 – The discovery of quantification and the semiosis of the natural world

In the rest of the 1870’s, Peirce abandoned temporarily the dispute nominalism-realism and made a great effort to promote his Pragmatism in the meetings at the Cambridge Metaphysical Club. Besides that, he was interested in developing an algebraic logic inspired by the recent works of Boole. He started to harvest what nearly ten years of studies had produced in 1883, when Peirce and his most brilliant student at Johns Hopkins, Oscar Mitchell, concluded that the logic needed indexes to express the idea of quantification (Short, 2004, p.12). In other words, they discovered the need to use selectives such as “some” and “all” to indicate the subject of a predicate. They discovered quantification independently of Frege, who had come to the same idea of quantifiers but whose work remained unknown. In this same period, Peirce studied Cantor’s ideas about the continuum (Houser, 1998, p.xxviii), which inspired him to develop his own hypothesis about what later would be called set theory.

These important advances led him to reformulate his philosophical system and had an important impact in semeiotic too. The quantification through indexes, for example, led Peirce to recognize that the world exterior to mind possess an undeniable reality and that logic had to incorporate this lesson in its notational system. In another important text about the algebra of logic, published in 1885, Peirce wrote that a complete logical notation should possess general or conventional signs (symbols), quantifiers or selectives of the same nature of demonstrative pronouns (indexes) and signs of resemblance. Peirce no longer considered the index a secondary element in the process of knowledge and representation.

One crucial effect related to the new place assumed by the index in Peirce’s logic was the abandonment of the previous thesis that all cognition necessarily precedes another (the thesis of the “train of thought”). Just like a pin used to pinpoint an individual place on a world map board, the index selects a particular occurrence of a general concept, which then becomes the subject of a predicate. As a result, if an index is existentially connected to the subject that it denotes, then so is the proposition connected to the same subject. That means that cognitions do not have to be necessarily chained to one another ad infinitum, but they may begin in perception.

With the new role reserved to the indexes, Peirce also refined the terminology of his semeiotic. What was called “resemblances”, “copies” and “images”, then began to be called icons; and the hypothesis, which had been presented for the first time in articles about cognition, now received the name of abduction or, alternatively, retroduction.

At this same time, Peirce adopted the notion of degeneration, borrowed from projective geometry, and applied it to his logic of relations. Thus, now he explained icons, indexes and symbols as derivations from three different types of relation that a Sign could have with its object, according to the theory of categories. The icon relates in a monadic manner with its object, be it by resemblance (when sign and object share the same property) or by exemplification (when the object is a property the sign possesses). The index presents a dyadic relation with its object, for it has a real connection with it. Only the symbol possesses a genuinely triadic, and therefore, intrinsically logical relation with its object, having the power to represent it by an arbitrary convention (CP 2.274).

While the bond between semeiotic and categoriology had been tightened, in 1887, Peirce fostered a controversy against the mechanistic vision of the universe defended by Spencer (cf. CP 1.33). According to Peirce, a purely mechanical causation, such as the dyadic cause-effect, is not able to explain the phenomena of growth and development present in the universe. There was the need to assume, therefore, a third element considered “virtual”, in the sense of having a virtue that would be put into effect in the future. Peirce’s universe is not mechanistic, but teleological and guided by purposes.

The conception of final causation was the first step towards the creation of a metaphysical semeiotic, with semiosis considered as the teleological movement of a reality composed by signs – a vision that would only be put into effect two decades later. Around 1888, Peirce affirmed that there were only three active elements in the world: first, chance; second, law; and third, habit formation. Although there was still no explicit identification among these three ontological stages and the sign trichotomies, Peirce was walking rapidly in this direction.

Other important steps for the synthesis between metaphysics and semeiotic occurred between 1892 and 1893, when Peirce formulated his doctrines of tychism (the existence of the absolute chance) and synechism (the existence of a profound connection among all things of the universe, expressed in the form of a continuum). In its exposition of tychism, chance (or spontaneity) is considered a creative element of a universe conceived as living mind. Matter is nothing but effete mind, whose creative power had been attenuated by habits in the form of laws of physics (CP 6.158).

In the mid-1890’s, and as another consequence of his studies about the role of the index in logic, Peirce proclaimed his acceptance of what the medieval scholastic Duns Scotus defined as haecceitas, or a pure existent hic et nunc, without involving quality or generality (Houser, 1992, p. xxvii). This “outward clash” brings changes in his way of seeing pragmatism: reality is no longer considered what the last opinion of a process of inquiry will effectively reveal, but simply the hope of a final accordance that stimulates the community of inquirers to continue their search. In other words, reality starts to assume a conditional mode: it is what would be revealed if all the possible efforts of inquiry were performed while absolute chance keeps adding creative novelties that continuously influence the evolutionary process.

Still between 1895 and 1896, Peirce wrote several drafts for a chapter of a book of logic that was never completed. In these manuscripts, he showed once again the intimate relations between logic and semeiotic, explicitly comparing semeiosis with mental reasoning. According to Peirce, a proposition, for instance, should always contain icons and indexes. Besides, abduction is emphasized as the only kind of reasoning capable of offering new knowledge and, therefore, essential for the developments of logic and sciences in general. Peirce explains abduction as a kind of instinct based on the affinity between our mind and nature. He concludes that the logic of pragmatism is essentially abductive, attached to non rational and probably non-conscious processes of the mind.

Finally, while his semeiotic was continuously being enlarged to comprehend non rational phenomena, Peirce began to distinguish two senses for logic: a more traditional one, restricted to the forms of inference and their conditions of truth; and another much more comprehensive, in which he could glimpse a general theory of signs that exceeded the limits of traditional logic to comprise the vestibules of reason.

Third phase: 1896 to 1905 – The studies of perception and the 1903 classification

The third phase starts when Peirce takes a further step towards a logical realism to accept, in 1896, the universe of the possibilities as ontologically present in the world (Short, 2004, p. 15). In 1897, Peirce advocates a kind of realism that resembles that of Aristotle, but with special emphasis on the haecceitas of Scotus. Peirce now considers the three categories – possibility, reaction and mediation – as complete and irreducible, finally naming them firstness, secondness and thirdness, extracted from mathematics. This new ontological vision led Peirce to re-exame his studies about cognition, conducted previously under strong Kantian and nominalistic influence, to present them in accordance with the new realistic clothing of his philosophy.

In 1898, William James, the old friend from the Metaphysical Club during the 1870’s, and then considered one of the most outstanding North-american intellectuals, made public that Peirce was the creator of the philosophy of pragmatism. The agitation that followed this announcement produced a double reaction in Peirce: on the one hand, he began to criticize openly and acidly all those who used the term pragmatism out of its logical range, without sparing even his friend and benefactor James, whom Peirce blamed of maculating pragmatism with psychologisms. On the other hand, Peirce assumed the responsibility of revising the basis of the pragmatism, offering to this doctrine a definite logical proof. He hoped to accomplish that by using the instruments and concepts in logic and semeiotic he had implemented since the first formulation of the pragmatic maxim.

The beginning of the 1900’s relit in Peirce the desire to write a book compiling the results obtained in his studies in logic, modality and topology, as well as the latest developments in the logical syntax of Existential Graphs. He came to produce a brief sketch of the themes he would tackle in such a book – considered today the best display of Peirce’s logical architecture made by his own hands (cf. CP 4.227-322). However, his hope of systematizing his recent contributions was once again frustrated because he did not receive the financial support he expected to carry the project forward. While waiting for a grant that would never come, Peirce returned to his theory of sign in search for the desired proof of pragmatism. At the same time, James invited Peirce for two series of conferences to be held in 1903: one in Harvard, dedicated to Pragmatism and the other at Lowell Institute, in Cambridge, directed to logic.

The consequence of this double stimulus – the search of a sound proof of pragmatism and the preparation for the coming conferences – was a complete revision of his semeiotic, for it became clear to him that semeiosis was linked to the laws of nature. In fact, in 1902 Peirce returned to his articles and manuscripts produced between 1891 and 1898, most of them dedicated to the discussion of the theory of evolution and its relations with the laws of physics. Reading this old staff through the new metaphysical light, he concluded that the purpose that guides the evolution of the species and the laws of universe cannot be based on consciousness but, on the contrary, it is consciousness that should be considered a sub-product of a telic movement towards a final purpose. This is, summing up, the Aristothelic thesis of the final cause and Peirce adopts it as a fundamental component for the development of the sign, based on semeiosis.

Peirce concluded that logic and semeiotic should be considered synonyms for being animated by the same leading principle. Borrowing the medieval division of liberal arts in Grammar, Logic and Rhetoric, Peirce for the first time announced his famous division of Semeiotic in Speculative Grammar, Critical and Speculative Rhetoric (or Methodeutic). Still in the ambit of the conferences about pragmatism scheduled for 1903, there was the need of approaching once more the problem of the origin of knowledge. Peirce faces it under the phenomenological point of view of perception, taking advantage of his studies in quantification and of the role of index in logic. Beginning in 1902, but carrying on for the next four years, Peirce developed a new theory of perception, destined to conjugate his logical realism with his fallibilism, and which would have its first presentation in the lectures of Harvard in March 1903.

Peirce explains that our first logical premises are born from the contact with reality through perceptual judgments. This does not mean that these judgments are intuitions about the real – which would mean a surrender to the Cartesian thesis he had so hardly combated in the articles about cognition. It is thus impossible for us to know immediately the relations among things. We can only make uncontrolled and non-conscious suppositions about these relations in such a way that these hypotheses are blindly accepted and would be criticized only if contrasted with reality, eventually bringing new suppositions to the mind. With this ingenious thesis, Peirce gives an answer to the question of the first cognitions without having to resort to the endless train of thought, which implies an infinite regress. And Peirce was able to do this without affecting his doctrine of fallibilism, considered by him a fundamental pillar of pragmatism (Short, 2004).

In some moment between the conference in Harvard and the writing of the Syllabus for the conferences at Lowell Institute, held in October 1903, Peirce had an insight that led to an important change in the structure of his classification of the Signs. According to Freadman (2004), this change is evident in the way the sign divisions complicate if we compare the ones Peirce had given before. For the first time, he presents the types of signs as composed by classes created by relations among three trichotomies. That is, for the first time it appears what in the Syllabus he would call first correlate, or the trichotomy of the sign “itself”, without any reference to its object or interpretant.

Peirce affirms that a class of sign is a relation of three correlates. In the first one, the sign can be a monad (qualisign), an existent object or singular event (a sinsign) or a type of law ruling its replicas (legisign). In the second correlate, which considers the relation of the sign and its object, the sign can be one of the already known icons, indexes and symbols. Finally, in the third correlate the sign can be a rheme (the generic sign for the logical terms), a dicisign(the generic for propositions) or an argument (the generic for syllogisms or inferences). Following an order of material implication, wherein the first correlate determines the third by means of the second, Peirce comes then to classify ten classes of signs that he calls genuine and distributes them in an inverted pyramid.

After the presentation of ten genuine classes of signs, Peirce also shows some of their possible degenerations and their utility for logic. Given the audience of the Lowell Institute, there is no doubt that the Syllabus and its preparatory manuscripts reflect Peirce’s concern in making explicit that his semeiotic was a synonym for logic conceived according to sound mathematical principles. This focus on the entailment semeiotic-logic seems to have produced a radical change in the way which Peirce conceived the signic relations. This is in accordance with the development Peirce gave to his Theory of Sign in the following years, which will no longer make use of the terms and concepts created before 1903, but actually emphasizes and unfolds the results of his studies in that year.

Another important event in Peirce’s intellectual life, closely related to his semeiotic, happened in 1903. It was the beginning of his correspondence with Victoria Lady Welby. She was a British woman who had been researching about the processes of meaning and interpretation. Peirce had reviewed favorably Welby’s book What Is Meaning?, opening the door for a fruitful exchange of letters that lasted until 1911, one year before Welby’s death. These letters are a precious source for those interested in following the huge transformations Peirce applied to his theory in the final period of his life. Some scholars even believe that Welby had a decisive influence in this phase. This would explain, at least in part, why Peirce dedicated such an effort to unveil the types of interpretants – sharing with Welby the same field of inquiry.

After grounding knowledge on perception and developing a sign taxonomy that seemed acceptable to deal with most logical problems, Peirce moved his attention to the third ramification of semeiotic, the Speculative Rhetoric. His intention was to approach once again the effects produced by the action of the Sign over its interpretant, but now seeing these effects from the results obtained in the former years. In 1904, for example, Peirce came to affirm that the representation had the power of causing real facts (EP: 300), and that the interpretant of the sign did not need to be necessarily a concept, as professed his intellectualist version of his first formulation of Pragmatism. They could be feeling and physical effects, too. Through that, Peirce anticipates the ontological division of interpretants in emotional, energetic, and logical that he would make explicit in 1907, taking his theory of signs to a new level of complexity.

Fourth phase: 1905 to 1914 – The multiplication of trichotomies and the notion of ultimate interpretant

The last phase of Peirce’s semeiotic is the least known and understood. This is due to, in part, the fact that it represents a revolution in the way Peirce understood his theory, probably motivated once again by his concern to link semeiotic with Pragmatism as well as with his metaphysical cosmology. While he smoothed over the matters in order to adjust one discipline to another, Peirce would make constant alterations in the sign classification, most of them tentatively. The pages of his logical notebooks written in this period are full of sketches of classifications, introductions of new terms, a profusion of triadic divisions and many geometric drawings, mainly triangles, used heuristically to explore and make evident the relations among the elements of the classes of the signs. Many of these drawings are contradictory and although most of them are dated, Peirce did not authorize us to simply consider the posterior versions as improvements from the previous ones. Whenever Peirce came to an impasse in the research, he would frequently return to the old classifications, sometimes created many years ago, dismissing as incorrect the recent attempts.

In 1905, Peirce adopted a realistic notion of thirdness, that he interpreted as a kind of conditional future, a would-be that could not be reduced to any series of instances. Consequently, he then explicitly corrected his 1878 opinion about the hardness of the object being a matter of subjective opinion and declared that it depended on pragmatism to insist about the reality of general potentialities in nature (Short, 2004, p. 15). The acceptance of the reality of the laws of nature, considered then as habits analogous to the beliefs of the mind, stimulated Peirce to approximate semeiotic a bit more (which had already been extended to comprise symptoms and physical signals) to this ever more realistic pragmatism. After all, the pragmatic kernel was precisely the notion of the habit of conduct. Habit became a keyword linking semeiotic and pragmatism.

In a series of articles written for the philosophical journal The Monist during that period, Peirce made the first attempts to extract from semeiotic a definite proof of Pragmatism or, more appropriately, pragmaticism, as he started to call his philosophy in an attempt to dissociate it from the version popularized by James and his disciples. In order to fight the nominalism that infected these popular versions of Pragmatism, Peirce emphasized that his proof should also be a proof of realism, in which the truth must be considered as what would appear in the final opinion of the research made by a community ideally infinite and honestly dedicated to this search. Note, however, that he still considers the summum bonum of pragmaticism as being a concept, i.e. reality is still what will appear in a symbol synthesized by an ideal mind summing up the minds of all members of a community of researchers.

In the course of these researches, Peirce discovered that his logic, seen already as identical to semeiotic, could be expressed through a visual syntax based on graphics – named Existential Graphs by Peirce – capable of performing the manipulation of the logical signs in a much better and more concise way. Although Peirce presented two quite developed versions of this graphical system, he could not complete them the way he had wished, probably barred by difficulties to represent the idea of continuum. However, his research about the Existential Graphs triggered a new branch of logic that has been producing promising results in more recent years.

As Peirce himself points out in a letter to Lady Welby, between 1905 and 1906 he worked intensively over his classification of signs. This new round of inquiries convinced him that a complete classification of all possible signs would demand at least 10 trichotomies that, if freely combined, could result in an astonishing figure of 59,049 Classes of Signs (CP 1.291). Nevertheless, Peirce explains, if we impose some logical mathematical limitations, the total number of classes would be restricted to only 66. Peirce also affirms that he had found the need to distinguish between two semeiotic objects (the immediate, present inside the sign, and the dynamic, which always remains out of the sign) and three types of interpretants that he names as intentional, effective and communicational – but which later would be called immediate, dynamic and final.

Short (2004) states – and we agree – that the introduction of these three interpretants does not substitute the trichotomization made in 1904, when he divided the interpretant into emotional, energetic, and logical. The trichotomy immediate, dynamic and final pertains to the sign considered as a system of relations in evolution or, in other words, as a class of sign. The division in emotional, energetic, and logical expresses the ontological status that each one of the interpretants (immediate, dynamic and final) can assume. When the sign is analyzed in its elements and relations, the first division occupies a horizontal axis; the second, a vertical axis. The result of the combination of both of them is that the process of interpretation always occurs in three types of interpretants chosen among nine possibilities.

There is no doubt that this proliferation of interpretants reflects Pierce’s increasing concern with the third branch of the semeiotic trivium. Nevertheless, he does not see rhetoric as identical to methodeutic – the science that studies the methods to be applied in the scientific inquiry. He now sees methodeutic as rhetoric in the narrow sense (Bergman, 2000, pp.246-247) while rhetoric in the broader sense must consider semeiosis in all possible dimensions. Deducing the implications of increasingly panpsychist cosmology, Peirce concludes that the process of interpretation does not happen only in human minds. On the contrary, it is the reality of interpretation of signs in the world that explains the emergency of human intelligence. As we have already seen, the universe is a quasi-mind perfused with signs. Trying to discover the “real thing” behind the veil of signs is a foolish illusion for, as Peirce writes in 1906:

“… these signs are the very thing. Reals are signs. To try to peel off signs & get down to the real thing is like trying to peel an onion and get down to [the] onion itself, … If not consciousness then sciousness, is the very being of things; and consciousness is their co-being. … (apud Brent, 1993, p.300)

This vision of the universe as quasi-mind leads Peirce to introduce, still in 1906, the idea of commens or co-mind, a kind of mental substratum that permeates and shapes the reality. Now Peirce considers the co-mind as a necessary pre-supposition so that the sign can transfer the form of the object to the interpretant in the process of communication (Houser, 1998, p. xxx). Note that the co-mind is neither the fusion of two human minds that communicate, nor just the fusion of minds of a finite community of people, such as a group or society dividing beliefs and common purposes, as preached by his former versions of pragmatism.

The co-mind is, generically, the fusion of object, interpretant and sign at the very moment of communication, when information is transmitted from the object to the interpretant and having the sign as a medium. If we parallel this process with communication, the object assumes the position of an emitter (utterer) and the interpretant, a receptor (interpreter). The sign is the medium and, finally, the message is the form or idea (information) to be transmitted by the sign.

With the introduction of the concept of co-mind, Peirce was very close to a complete fusion between his theory of sign and pragmatism. The last step would be the elimination of the intellectualist anchor he had placed over his philosophy when he affirmed that the final interpretant of a concept could only be another concept, i.e. a symbol. This barrier is finally overcome in 1907, when Peirce develops the concept of ultimate logical interpretant. According to Peirce, the ultimate instance of interpretation cannot be a symbol, a concept or a thought because this would allow it to be interpreted in further thoughts, eventually ad infinitum – as Peirce had  sustained in the 1860’s in his juvenile articles about cognition. In order to avoid a possibly infinite progression, Peirce gave to the ultimate logical interpretant the status of a habit or, even better, the habit of habit-change, or the habit of breaking one’s own believes in the pursuit of truth.

In 1909, while Peirce drafted “A system of logic, considered as semiotic”, he affirmed that the ultimate interpretant was not the way a finite group of minds effectively act under the influence of a concept, but as any mind, in the general sense of the word, would act under its effect. This is an important modulation because it harmonizes the general term of logic and semeiotic with his idea of thirdness present in nature, as he had announced in 1906. The conditional future, the habit that does not exhaust itself through any number of occurrences—or better put, the very change of the habit towards full reasonability—is now considered the ultimate purpose of his pragmatism.

Scholars disagree about the exact place of the ultimate interpretant in the semeiotical classification. Savan (apud Santaella, 2004, pp 78-87) believes that it is the highest degree of thirdness applied to the dynamic interpretant because it is the dynamic interpretant that refers to the effects produced in the mind of the interpreter and is capable of generating deliberate conduct. The other two interpretants, immediate and final, are not that crucial for the pragmatic method. In our opinion, though, it is up to semeiotic, as the general theory of signs, to consider the ultimate instance in the immediate and final interpretants as well. When the ultimate instance occurs in the immediate interpretant, we have a habitualized interpretability of non-conscious processes; when it occurs in the ambit of the final interpretant, we have the very sign assuming a habitual, or general, future consequences, i.e. becoming a legisign.

If on the one hand semeiotic and pragmatism now appear connected by the concept of habit, on the other hand this union obliged Peirce to review the strength of the pragmatic maxim because a habit is not sustained by logical considerations only, but by ethical and esthetical as well. No wonder thus, that Peirce started to place ethics and aesthetics as normative sciences responsible, together with logic, for controlling human conduct. Pragmatism (or pragmaticism), is then redefined as a scientific method closed linked to deductive logic. In fact, in October 1913, a few months before his death and while writing his last article, Peirce shows uncertainty about the validity of pragmatism, for his method of clearing up ideas might have clung too much to analytical deduction while neglecting the creative power of abduction, or uberty (EP2, p.463).”

While pragmatism is kept restricted to intellectual minds, semeiotic does not suffer from this limitation and spreads out through all possible fields of phenomena. When searching in his theory of sign for a definite proof of his pragmaticism, Peirce ended up taking semeiotic to the maximum degree of transdisciplinarity. If the universe is made of signs, and semeiosis is another name for communication, as Peirce seems to maintain in the final phase of his intellectual life, then a unified theory of reality seen as a process of development of information, if we should be able to conceive it someday, will necessarily involve semeiotic.