Peirce. Truth and the public

Peirce. Truth and the public

Author: Juan Pablo Serra
Published in: La Torre del Virrey. Revista de programs of study Culturales. Nº 2, 2006/2007, pp. 51-54
Publication date: 2006/2007

If we were to stick to history, we would say that Charles Sanders Peirce was a 19th century scientist B , best known for his work on pendulum oscillation and stargazing, in which he succeeded in refining the geodetic and astronomical measurement methods of the time * (1). If we were to stick to what he wanted to be, then we would undoubtedly affirm that he was a logician, discipline which he studied since he was a child * (2) and to which he was ahead of his time with his logic of relatives and the theory of quantifiers. And, if we consider the thematic breadth of his work, we would have to agree that he was a philosopher in the most classical sense of the term, since he was interested in practically all fields of knowledge and tried to establish his own system of thought * (3).

The reception of his work in the intellectual sphere from the 1970s onwards was somewhat strange, in the sense that his relevance (thanks to the praise of Bertrand Russell, Karl Popper, Karl-Otto Apel, Umberto Eco, Hilary Putnam, Walker Percy...) was more important than his knowledge* (4). Nevertheless, while he was still alive, his contributions to mathematical logic were recognised (as stated, for example, by the Spanish mathematician Ventura Reyes y Prósper in an 1891 article * (5)) and he even appeared under the profession of "logician" in the sixth edition of the guide Who's Who in America (1910-1911). Later, towards the end of the 20th century, it was his theory of the sign that made him most famous, probably because, as Castañares states, Peirce's true knowledge "has been produced either from semiotics or when semiotics has reached a certain maturity" * (6).

An aristocrat eager to be understood

Born in Cambridge in 1839, Peirce grew up in a highly respected family within the cultural and academic milieu of Boston. Benjamin Peirce, his father, was a prestigious professor of astronomy and mathematics at Harvard and also one of the most powerful figures in American science. In 1859, he secured him a temporary work as teaching assistant on two expeditions of the U. S. Coast Survey - the leading scientific institution of the time, which Charles joined as a calculating assistant in 1861 and served until 1891. At the same time, from 1867 to 1875, also through his father, Peirce was making observations at the Harvard Observatory. Charles worked alongside his father between 1867 and 1874, the years when his father was director of the Coast Survey. In 1877 he was elected a member of the National Academy of Sciences, a scientific body that had been established as an official advisor of the federal government at the urging of Benjamin Peirce and other academic colleagues. And from 1879, again on the recommendation of his father and William James, Peirce was professor of logic part-time at Johns Hopkins University.

But, despite what it might seem, to contemplate his biography is more like attend to the story of a failure, because, from being a child prodigy promoted and protected by his father * (7), Peirce went - after his father's death - to unemployment and misery * (8). In 1884 he was abruptly dismissed from Johns Hopkins and in 1891 his contract with the Coast Survey was terminated. Nevertheless, from 1887 - when he retired with his second wife - until his death in 1914, he published an astonishing number of definitions for dictionaries and book reviews and worked busily to develop his own philosophical system in countless essays, most of them unpublished.

In one of these articles, "Guessing", written around 1907 and published posthumously in a journal produced by Harvard students* (9), Peirce set out to set out his ideas about human knowledge . To this end, he brought together some views he had already expressed in a series of articles published in the Journal of Speculative Philosophy almost forty years earlier, added an account of an experience staff on a ship, and included a non-technical summary of an experiment conducted on a former student of his own. With all this, Peirce intended to defend "the existence of a spontaneous, instinctive human ability to guess the correct hypothesis" * (10). But, above all, he wanted to do so in an informative way.

And it is true that, in the public eye, the figure of Peirce is obscure and not very accessible. There are even authors like Rorty who describe him as a "brilliant, cryptic and prolific polymath, whose writings are very difficult to assemble into a coherent system" * (11). Nevertheless, Peirce wanted to be understood by the common man and, what is more, "he knew how to popularise; we know this from his articles in the Popular Science Monthly, The Nation and other periodicals. But these were intentionally popular writings" * (12). Thus, in many of these popular articles, Peirce either addressed the reader in the first person and with great delicacy, or he filled his writings with long illustrative examples.

Another difficulty in understanding his thought perhaps lies in the fact that Peirce was above all a logician, and in his most important texts terms such as "eventually", "conceivably", "possibly"... appear continually in his most important texts. In other words, he gives the impression that he is talking about possible and distant worlds rather than about the real, actual, everyday world. But this is no more than a mere sensation, because for him, logic was the study of methods and above all the study of the methods of experimental science, not of possible science. goal In this sense, logic "connects" man with reality, because logic has to do with reasoning that wants to be correct, that is, with reasoning that is open to truth, the search for which is the ultimate goal of science * (13).

Guessing or abduction

"Guessing" is divided into two parts. In the first, Peirce explains how we form opinions that are able to explain what happens. In the second, he tries to show that we have a kind of instinct for guessing things. He begins article by equating "knowledge" with forming expectations:

Our knowledge of any topic never goes beyond collecting observations and forming some semi-conscious expectations, until we are confronted with some experience contrary to those expectations (CP 7.36, c. 1907). The knowledge begins with perception, which provides data, and continues with the training of beliefs about what happens; these, in turn, establish habits of action to deal with the world (CP 5.398, 1878). One doubts neither perception nor subsequent belief until one's expectations are disappointed by some surprise, which is the way experience teaches us (CP 5.51, 1903). This leads us to formulate a new hypothesis with which to try to understand and explain the new status. For, as Nubiola writes, "our beliefs are habits and as such force man to believe until something surprising, some new external or internal experience, breaks that habit. The surprising phenomenon requires a rationalisation, a regularisation that makes the surprise disappear through the creation of a new habit" * (14).

This process, which Peirce called 'abduction', always consists in supposing that the surprising facts we have observed are only a part of a larger system of facts, which (...) taken as a whole, would present a certain character of reasonableness which inclines us to accept the conjecture as true, or something like it" (CP 7.36, c.1907). If deduction explains and induction evaluates, in abduction we assume that a surprising fact is an instance of a general rule (CP 2.624, 1878). By means of imagination, in abduction it is we who introduce that wider general rule or status that would explain the observed surprising fact. Abduction is, therefore, a subject of inference whose conclusion is always a hypothesis (CP 2.96, c.1902) or a conjecture, something probable, but it is precisely the plausibility or reasonableness of that hypothesis that leads to its acceptance and not its actual probability (CP 2.102, 1903). To abduce is to guess * (15), and it is the only reasoning that generates new knowledge, because it adds to the data of perception a plausible explanation (MS 692, 1901). In "Guessing", Peirce proposes the example of someone entering a room for the first time and seeing, projected from behind a large map, three-quarters of a Raphael fresco. The viewer tends to forget the surprising fact that a part of the fresco is missing because an explanation arises naturally, like a flash of understanding (CP 5.181, 1903): the map is covering a quarter of the fresco * (16). In this way, "an interesting, simple and completely accepted inference tends to obscure all recognition of the complex and uninteresting premises from which it was derived" (CP 7.36, c.1907). The viewer might form several hypotheses as to why he is only observing three-quarters of a fresco, but he accepts the simplest hypothesis, because it is "the simplest Hypothesis in the sense of the easiest and most natural, that which instinct suggests" (CP 6.477, 1908). For Peirce, we are continually guessing. Moreover, "all knowledge is born of the hypothesis and, although every hypothesis is essentially fallible (...), it is the only way that can lead us to the truth" * (17). Even if we have some prior knowledge , there is a point of reasoning that remains creative. Peirce suggests in "Guessing" another example: this time, the surprising fact is a man's behaviour, which we tend to explain by supposing that man's belief that caused such behaviour. If we do not know that person, any belief that we claim explains his behaviour would be as good as any other. But, if we do know him, we still have to guess at his state of belief, only among a issue fewer cases or hypotheses (CP 7.37, c.1907). If we take these considerations to the realm of science, for Peirce there is no doubt that science has been constructed on the basis of propositions that were guessed among various possibilities (CP 7.38, c.1907), but not in a haphazard or fortuitous way, since "the human mind, having developed under the influence of the laws of nature, for that reason naturally thinks somewhat along the lines of nature's model " (CP 7.39, c.1907). That we are able to produce correct hypotheses is explained by a special affinity between our cognitive capacities and nature, so that as our minds have been formed under the influence of phenomena governed by the laws of mechanics, certain conceptions falling under these laws are implanted in our minds; hence we easily guess what these laws are. Without such a natural inclination, having to search blindly for a law that fits the phenomena, our probability of finding it would be infinite (CP 6.10, 1891). In fact, what surprises Peirce about scientific activity is that it achieves true explanation after a small issue of attempts. To produce hypotheses, one must assume that facts can be rationalised and, moreover, that man can rationalise them (CP 7.219, c.1901) because he has an almost instinctive capacity to conjecture correctly. To claim that the scientist gets it right by chance is tantamount to renouncing all explanation* (18). This is how Peirce puts it in the sixth of the 1903 Lessons on Pragmatism:

Consider the multitude of theories that could have been suggested. A physicist comes across a new phenomenon on his laboratory. How does he know whether the conjunctions of the planets have nothing to do with it, or whether it is not perhaps because the dowager empress of China happened to utter some word of mystic power a year ago, at that very moment, or whether an invisible genius was present? Think of the trillions upon trillions of hypotheses that could have been made, only one of which is true; and yet, after two or three guesses, or at the most a dozen, the physicist comes very nearly upon the correct hypothesis. By chance it would not have been plausible for him to do so in all the time that has elapsed since the earth solidified (CP 5.172, 1903). Finally, Peirce explains this peculiar connection of the mind with the phenomena of the universe by an actual anecdote that happened to him in 1879 when a valuable watch was stolen during a voyage to New York on a steamship. Realising the loss, he sent all the stewards up on deck and talked briefly with them. Finding no clue as to who the thief was, he decided to make a guess as to who it might be, "never mind if you have no reason, you must say whose thief you think it is" (MS 687, 11, c.1907). And having established a guess "all shadow of doubt was gone. There was no self-criticism" (MS 687, 11, c.1907), i.e. he accepted the hypothesis that caused him the least complications and let himself be guided by it. The waiter denied the accusation, but Peirce hired a detective and, in the end, recovered the watch from the person he had accused despite having no evidence. "Peirce concluded that he must have received subconscious hints during his conversation with the waiter, which led him to reach the right conclusion" * (19), so that, even without knowing it, he was able to conjecture correctly. It is the only way to explain, Peirce thought, that men have "some intuition of what goes on in the minds of their fellows" (CP 7.40, c.1907).

The inferred nature of the knowledge

In the first part of "Guessing", Peirce has advanced a conjecture about how knowledge works and explained it with various hypotheses and examples. But in the second part, Peirce goes a step further and tries to show that there is a true cause that produces conjectures which, more often than not, provide the correct explanation of phenomena. To do so, he brings up an experiment carried out between 1883 and 1884 together with Joseph Jastrow while he was at Johns Hopkins* (20). Both wanted to refute Fechner's theory of minimum thresholds of perception. This physiologist argued that below certain minimum magnitudes of stimulation, the human being does not "perceive" or, in any case, if he does perceive, he is not capable of discriminating sensations or stimuli. In other words, if a quantity of sound X is decreased by a minimum amount, for example X - 0.01 or increased by X + 0.01, the subject is unable to notice the difference.

Peirce was opposed to this idea because, for him, it was unacceptable that human beings should begin to perceive beyond a certain threshold. If there is one constant in Peirce's thought, it is the insistence on the continuity between one thought and another, between one perception and another, or - as he wrote at the beginning of his degree program- between one cognition and another. If there were such a thing as a "threshold", this would imply that there is a point at which man, so to speak, "begins" to know. For Peirce there is no such point, because all thoughts are signs, which come from other thought-signs and which, in turn, give rise to new thoughts. But, in addition, accepting the existence of a "threshold" implies that there are fields of experience - however infinitesimally considered - that are unknowable and, for Peirce, all regions of experience are fields of possible experience. In the experiment - which, incidentally, is now accepted as the beginning of experimental psychology - a subject is given pressure and, depending on what a randomly chosen card says, a minimum amount is added to or subtracted from that same pressure. The subject was asked to say whether he or she noticed such a change. If Fechner was right, since the varied quantity is infinitesimal, the subject would not consciously perceive this change, so the answers he gave would be totally random (50% right and 50% wrong). What Peirce observed is that there is a slightly greater tendency to get it right (3 out of 5). A result which gives new reason to believe that we grasp what is going on in the mind of another largely by sensations so faint that we are not fully conscious of having them, and cannot give an explanation of how we come to our conclusions on such matters (CP 7.35, 1884).

What he was demonstrating at final was that all knowledge is inferential, that there are no pure intuitions, but that - somehow - all knowledge comes from another. It is an idea that he had already argued in the Cognition Series, a series of three articles published between 1868 and 1869. At the end of "Questions about certain Schools attributed to man", Peirce attacks the idea that there are cognitions not determined by other cognitions and uses the example of the inverted triangle that is gradually submerged in water. The surface of the water leaves horizontal lines at different times as the triangle is immersed.

Suppose that the lines symbolise the vividness of each cognition and that each line determines the next as it dips: the longer the line, the more vivid the cognition of the object. What is found is that it is impossible to find two lines between which no more lines can be drawn. In other words, the knowledge is self-founding and, so to speak, there is no first knowledge that is not mediated by others. The unknowable is never reached. Certainly, one could argue that the vertex is the unknowable unmediated. But the vertex is a point, not a line, and would become not a cognition but the object itself - which is outside consciousness, in reality - to which cognitions refer. The moment the triangle is put in the water, the lines already appear. That is to say, the moment there is knowledge, there is already a succession of cognitions (CP 5.263, 1868).

Inference and truth

Peirce concludes "Guessing" by comparing the ability to guess to the ability of birds to fly and including this abductive instinct within the art of research: "we usually obtain from observations strong intimations of truth, without being able to specify what were the observed circumstances leading to those intimations" (CP 7.46, c.1907). Abduction, i.e. skill to form hypotheses, is the only way to access truth, which is "the property of those hypotheses which would be believed if the research [about them] were continued as far as it could profitably go" * (21). But this assumes that the human mind is akin to truth, in the sense that in a finite issue of conjectures it will illuminate the correct hypothesis. (...) For the existence of a natural instinct for truth is, in the end, the lifeline of science (CP7.220, c.1901). For Peirce, science is "a living historical entity" (CP 1.44, c.1896) and "a growing and living body of truth" (CP 6.428, 1893), which matures on the basis of the successes and mistakes of researchers over time. The truth would be at the end of the research, it would be that belief on which the community of researchers would necessarily converge, the final opinion that is irrefutable. The hypothesis that this final point exists is the only thing that gives meaning to the succession of hypotheses that approach it. And it is, as Peirce says, the saving grace of science (Juan Pablo Serra is PhD student of Philosophy at the University of Navarra).



  1.  K. L. Ketner, "Charles Sanders Peirce. Introduction", in J. H. Stuhr (ed.), Classical American Philosophy, Oxford University Press, New York, 1987, pp. 14-18.

  2. His "meeting" with logic is described in a well-known letter to Lady Welby dated 23 December 1908. There he recounts that he saw Archbishop Richard Whately's Elements of Logic (1831) in his elder brother James's room, read it and from that day on "I have never been able to study anything (...) except as a study of semiotics" (in C. S. Hardwick, Semiotic and Significs: The Correspondence between Charles S. Peirce and Victoria Welby, Indiana University Press, Bloomington, 1977, pp. 85-86, see also p. 77).

  3. C. Hookway, voice "Peirce, Charles Sanders (1839-1914)", in E. Craig (ed.), Routledge Encyclopedia of Philosophy, Routledge, London, 1998, vol. 7, pp. 269-270.

  4. J. Vericat, "Introducción", in J. Vericat (ed.), Charles S. Peirce. El hombre, un signo, Crítica, Barcelona, 1988, p. 15.

  5. V. Reyes y P rósper, "Charles Santiago Peirce y Oscar Howard Mitchell", in El Progreso Matemático, 2/18 (1892), pp. 170-173.

  6. W. Castañares, "Ch. S. Peirce. Historia de una marginación", in Revista de Occidente, 1987 (71), p. 136.

  7. Cf. L. Menand, El club de los metafísicos, Destino, Barcelona, 2001, p. 162: "[Peirce] began his degree program under the tutelage of his father, and for the rest of his life he considered his own work to be an extension and enlargement of what his father had done".

  8. And even to lose his orientation in life, as J. Brent states in what is the canonical biography of Peirce, Charles Sanders Peirce: A Life, Indiana University Press, Bloomington, 1998, p. 132.

  9. C. S. Peirce, "Guessing", The Hound and Horn, II/3 (1929), 267-282. Here we take as reference letter, on the one hand, the extract from that article which appears in C. Hartshorne, P. Weiss and A. W. Burks (eds), Collected Papers of Charles Sanders Peirce, 8 vols., Harvard University Press, Cambridge, 1931-1958, 7.36-48, c.1907 (cited as CP, followed by the issue of the volume and paragraph and year of the text). And, on the other hand, the manuscript "Guessing", preserved in the Houghton Library, Harvard (cited as MS, followed by the issue of the manuscript and the year corresponding to the text, according to the numbering of R. Robin, Annotated Catalogue of the Papers of Charles S. Peirce, University of Massachusetts Press, Amherst, 1967).

  10. S. Barrena, "Introducción", in C. S. P eirce, Un argumento olvidado en favor de la realidad de Dios, Cuadernos de yearbook Filosófico, 34 (1996), Pamplona, p. 44.

  11. R. R. Rorty, "Pragmatism", in Routledge Encyclopedia of Philosophy, vol. 7, p. 633.

  12. P. Skagestad, The Road of Inquiry, Columbia University Press, New York, 1981, p. 15.

  13. C. S. Peirce, "The Nature of Science", in yearbook Philosophical, XXIX/3 (1996), p. 1437 (original in MS 1334, 1905).

  14. J. Nubiola, "La abducción o la lógica de la sorpresa", in Razón y Palabra, 21 (2001), electronic edition available at

  15. "The subject of no new truth can come from induction or deduction. It can only come from abduction; and abduction is, after all, nothing more than guessing" (CP 7. 219, c.1901).

  16. Despite this almost instantaneous and instinctive character, abduction involves observation (the three quarters of the fresco), imaginative manipulation of the observed facts (imagining that one can only see a piece of the fresco because something is covering the rest) and the formulation of an explanatory hypothesis (the map covers a quarter of the fresco). In any case, Peirce could have gone further, because one cannot be aware of being before a surprising fact until one has a hypothesis that explains it: one cannot know that one is before ¾ of a Raphael's fresco until one has the hypothesis that the whole fresco is there, only partially covered by the map. That is to say, that even the surprise demands an explanation that makes it "surprise".

  17. G. Debrock, "The Ingenious Enigma of Abduction", in Philosophical Analogy XII/1, (1998), p. 21.

  18. G. Genova, Charles S. Peirce: La lógica del finding, Cuadernos de yearbook Filosófico, 45 (1997), Pamplona, p. 68.

  19. L. Menand, The Metaphysicians' Club, p. 372.

  20. C. S. Peirce and J. J astrow, "On Small Differences of Sensation", in Memoirs of the National Academy of Sciences, 3 (1885), pp. 75-83. Cf. M. M orgade, Charles Sanders Peirce en la psicología, doctoral dissertation, Universidad Autónoma de Madrid, 2004, pp. 536-538.

  21. C. Misak, Truth and the End of Inquiry, 2nd edition, Clarendon, Oxford, 2004, p. 44.