Moscow, HSE, Faculty of Philosophy

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Seminar 11/4/2011

Peirce’s Anticartesianism

Lorenzo Vinciguerra

Je ne peins pas les choses, mais les relations entre les choses

Georges Braque

In my work I am interestered in what we could call the inner critique and resistance to the mainstream of Western tradition. My research on Spinoza followed this path, of what has been called the “Marrano of Reason” (Yovel), or the “Savage Anomaly” (Negri). My interest for Peirce is partly due to similar reasons.

Some major currents of philosophy such as phenomenology of Husserl, as well as the avant-garde artists of the late nineteenth century, as are in part issued from a meeting with experimental psychology. Chevreul’s, Wundt’s, Fechner’s researches proposed to give a positivistic explanation of sensation, perception of space, perception of colors and shapes. These issues traditionally refer to aesthetic. But they are older. They used to belong to the socalled science of the soul, the old psychology. The philosophical premises of this scientific approach are in Descartes, in his dualism and mechanicism. This tradition then developed through the English empiricism, to metamorphose in the Kantian transcendentalism. Charles Sanders Peirce shares with this tradition the scientific approach and the hypothetical nature of knowledge. He was among the first in the United States, long before William James, to be interested in Wundt and Fechner, whose he had in mind to translate the works.

Here I will not recall the best-known theories by Peirce (I mean the triadic model of sign), which were often references for semioticians. I shall instead pay attention to his first texts devoted to intuition. His critique is indeed radical and and very large. It prepares future developments of the Peircean semiotics. It concerns all areas in which we make reference to intuition: a theory of perception, psychology, as well as metaphysics. Peirce calls into question the general epistemological model that underpins the tradition running from Descartes to Kant, and all that it inspires.

In 1868 Peirce published two important articles in the Journal of Speculative Philosophy, entitled: Some Questions Concerning Faculties Claimed for Man and Some Consequences of Four Incapacities. In these articles, he makes radical arguments against what he calls “the Spirit of Cartesianism”. He says that Descartes is the father of Modern Philosophy, and the Spirit of Cartesianism – that which principally distinguishes it from scholasticism which it displaced – may be, compendiously stated as follows: 1- Descartes teaches that philosophy must begin with universal doubt; 2- that the ultimate test of certainty is to be found in the testimony of the individual consciousness. On these respects, most modern philosophers, argues Peirce, have been Cartesian: «It seems to me that modern science and modern logic require us to stand upon a very different platform from this».

On the first point, Peirce shows that Descartes’ doubt is not a real doubt. It is no more than a fiction which is not a positive reason to really doubt. Descartes’ doubt is just unbelievable. Without quoting him, Peirce shows to be very close to Spinoza’s argument against Descartes. Doubt cannot be a only a formalistic experimental thought: it must enbody a unconfortable crisis in the mind, that is to say two positive reasons excluding each other. To doubt (dubium) means to balance (fluctuare). «Let us not pretend to doubt in philosophy what we do not in our hearts» – writes Peirce, showing by that how philosophy must pay attention to experience and experiment. Nietzsche will develop similar considerations with the idea that it is impossible to doubt that we do have a body.

On the second point, Peirce critizes the subjectif Cartesian criterion of certainety founded on evidence, which amounts to this: “Whatever I am clearly convinced of, is true”. Peirce answers that if I were really convinced, I should have done with reasoning, and should require no test of certainety. And he adds that «to make single individuals absolute judges of truth is most pernicious». Here again we can think about Spinoza’s argument against the cartesian selfevidence of freedom (I will come back later on this point).

In these two articles of 1868, Peirce gets to four very important conclusions:

1) We have no power of introspection, and all our knowledge of the internal world is derived by hypothetical reasoning from our knowledge of external facts;

2) we have no power of intuition, but all our knowledge is determined by prior knowledge;

3) we do not have the power to think without signs;

4) we have no conception of the absolutely unknowable.

I will focus particularly on the second thesis. It has a very broad reach. What does here intuition mean? Echoing Duns Scotus, Peirce says that the notion of intuitive knowledge had two meanings in the Middle Ages: as opposed to the abstractive knowledge, intuition means the knowledge of present as present. But, as it was assumed that no intuitive knowledge could be determined by prior knowledge, intuition became opposite to discursive knowledge. It is in this sense that Peirce uses it. By intuition he intends a knowledge, whatever it can be, not itself determined by prior knowledge. In other words «a premiss, which is not itself a conclusions». Well, according to Peirce, it is an illusion to think we could have such a simple and immediate knowledge:

Now, it is plainly one thing to have an intuition and another to know intuitively that it is an intuition, and the question is whether these two things, distinguishable in thought, are, in fact, invariably connected, so that we can always intuitively distinguish between an intuition and a cognition determined by another. Every cognition, as something present, is, of course, an intuition of itself. But the determination of a cognition by another cognition or by a transcendental object is not (…) a part of the immediate content of that cognition. (…) There is no evidence that we have this faculty, except that we seem to feel that we have it.

In support of this idea, Peirce adds several arguments. They all show that it is not always easy to distinguish between a premise and a conclusion and that in any case we have no infallible authority to do so. Any lawyer knows how difficult it is for witnesses to distinguish between what they have seen and what they have interpreted. Similarly, the content of a dream does not differ substantially from an actual experience, yet everyone believes that dreams are determined by prior knowledge. So if we advance as an explanation that the ability to intuitively recognize the intuitions is asleep, there is no more than a guess. Especially when we wake up, we do not find that the dream was so different from reality, except by certain marks, as Descartes had already noticed: darkness or fragmentariness (let us remember that on this particular point Spinoza used to say that the belief in our freedon is something like a dream with open eyes). Not unfrequently a dream is so vivid that the memory of it is mistaken for the memory of an actual occurrence. If we ask a child how he knows what he does, in many cases it will tell you that he never learned his mother tongue, he always knew it, or he knew it as soon as he came to have sense.

Also, since we are able to recognize our friends by certain appearances, although we can not say what these appaerances are, and we have no consciousness of making a reasoning, this should lead us to think that the more our reasoning is easy and natural, the more its premises, however complex they can be, tend to fall into oblivion. In other words, we are more confident to know something intuitively when we tend to forget the premises that actually support this belief.

This applies to the notions of space and time. For Peirce space and time are far from being intuitions. The course of time, indeed, can not be directly or immediately felt. In this case, there should be some feeling in each moment of time. But in an instant there is no duration, and hence no immediate feeling of duration in each instant. In other words, none of these basic feelings is an immediate feeling of duration; and hence their sum either. The same reasoning applies to the space of two or three dimensions. They appear as immediate intuitions, but they must be known by inference. Developing an argument, already in Berkeley, Peirce noted:

if we were to see immediately an extended surface, our retinas must be spread out in an extended surface. Instead of that, the retina consists of innumerable needles pointing towards the light, and whose distances from one another are greater than the minimum visibile. Suppose each of those nerve-points conveys the sensation of a little colored surface. Still, what we immediately see must even then be, not a continuous surface, but a collection of spots. Who could discover this by mere intuition?

Any excitation can produce an idea as complicated as that of a space so small it is. And if the excitement of any nerve endings in isolation is not capable of providing immediate impression of space, all the excitement can not do more. It is therefore inconceivable that «the brief excitation of a single nerve gives the feeling of space». Perceptions of space and time are rather conceptions that make the synthesis of impressions as numerous and as short as we please. But these impressions, which therefore play the role of prior knowledge, can not be captured in a unit clearly defined and isolated.

If there is no intuition, or at least it is impossible to distinguish intuitively between an intuition and an inference, that means there are no absolute data. In the same way, we often confuse what we call «reality» with the belief of a the transcendental existence of a outside standing world. Stricly speaking, for Peirce, it is real what forces us to produce some true propositions about it.

We find a similar understanding in his philosophy of mathematics. There is a kind of a paradox in mathematics: How is it possible both that mathematics is purely deductive in nature and derive their conclusions apodictically, and secondly they provide a series of discoveries as rich and endless as any observational science? How can we explain the fact that they expand our knowledge while carrying on a deductive reasoning necessary? O the way we respond depends the analytic on synthethic conception of mathematics, and the difference for instance between a necessary immediate inference (corollary) and mediate a necessary inference (theorem).

The problem is not new. It goes back at least to Euclide’s Elements, or rather to its editors, who distinguished in Euclide way of proceeding: the «proposition» (Protasis), the «exposition» (Ekthesis) and the «construction» (Paraskeues). The last is constituted by the addition of more complex figures to the initial one in order to help the demonstration. Hence there are two possibilities: either the conclusion is directly seen by simple inspection of the initial figure (with no need of modifying it), or it is necessary to modify it introducing auxiliary constructions (for instance, by extending one of its sides). In the first case we are dealing with an immediate inference, epistemologically trivial, since it merely states the premise of ways to be seized in an intuition (analytic in the Kantian sense) in the second, we are dealing with a mediate inference, that does increase knowledge. Now there are two opposite ways to consider these additions: as auxiliary and secondary tools, or as constituting the own practice of mathematics.

In 1914, the year that disappeared Peirce, Frege wrote "the truth of a theorem can not really depend on anything we do, since it exists quite independently of us (...); by drawing a line we just realize that exists independently of us». Frege, from this point of view adopted a platonic realism. On the opposite, for Peirce, such a tracing was not trivial. More than that, it is a real creation of our mind. This attention to signs, construction, handling of evidence without which there would be no thought is at the heart of his thinking on mathematics, as a science of hypotheses. It is an expression of his anti-intuitionnist pragmatism.

2. The first results of this analysis leads to the idea that no feeling, no sensation can be an intuition. In other words, from a logical point of view, rather than psychological (because psychologically speaking we do have the opposite feeling, as Descartes shows) the feeling cannot be a «premise that is not itself a conclusion».

From a physiological point of view of perception, Peirce excludes the hypothesis that there is some thing like a painting on the back of the eye. The blind spot on the retina proves for him that the visual field does not configure as a continuous space. That means that our perception of space is not an immediate intuition or a priori intuitive sensitivity as it was possible to think after Descartes, Newton or Kant.

In line with these thoughts, we realize that visual perception cannot be made out of images, if we mean by “image” something absolutely determined in all respects, that is to say in any detail. If this were the case, we should see all the detail that an image presents us. But it is never the case, as no one has in mind every detail of the path that leads him to his office. The existence of something like «a picture in our imagination» is no more than a belief that had a great importance for Descartes and his followers. Hume believed, for instance, that between the first perception of a book and its imagination, there was a difference in strength and liveliness. If this were the case, argues Peirce, we should remember a book that is less red at a first impression, yet we remember its color with great accuracy for a few moments.