Logical Positivists on the Cogito

Boran BerčićDepartment of PhilosophyUniversity of Rijeka

• I think, therefore, I am.

• A sentence is meaningful iff it is (1) analytic or (2) empirically verifiable.

1) Negative part: a critique

Georg Lichtenberg

• "It thinks, one should say, as one says: it lightens. To say cogito, is already too much, if it is translated as I think"

Friedrich Nietzsche

"It is merely a formulation of our grammatical habits that there must always be something that thinks when there is thinking and that there must always be a doer when there is a deed". (Carnap, Aufbau, 105: Nietzche Wille zur Macht, §276,309,367)

Moritz Schlick

Moritz Schlick

• The Cogito of Descartes, as we remarked earlier, contains the trap of a distinction between a substantivist "I" and its activity, into which Descartes fell when he added: ergo sum. For as is easily seen, his sum means for him the existence of a substantial "I". Lichtenberg's very true observation that Descartes should have said "It thinks" instead of "I think" , is not only an inspired remark but should really be made the supreme guiding principle of psychology. ... The stream of consciousness is simply an existing process; the "I" is the unified interconnection of this process, not a person who inspects and guides it. (Schlick, Allgemeine Erkenntnislehre, p. 161)

Moritz Schlick

• We are treading on the path which has been followed from ancient times by all those who have ever embarked upon the journey towards the ultimate grounds of truth. ... The Cartesian cogito ergo sum is the best-known of the destinations to which this path has led - a terminating point to which indeed Augustine had already pushed through. And concerning cogito ergo sum our eyes have today been sufficiently opened: we know that it is a mere pseudostatement, which does not become genuine by being expressed in the form "cogitatio est" - "the contents of consciousness exist". Such a statement, which does not express anything itself, cannot in any sense serve as the basis of anything. (Schlick, "Uber das Fundament der Erkenntnis", pg. 218)

Alfred Jules Ayer

Alfred Jules Ayer• What he (Descartes) was really trying to do was to base all our

knowledge on propositions which it would be self-contradictory to deny. He thought he had found such a proposition in "cogito", which must not here be understood in its ordinary sense of "I think", but rather as meaning "there is a thought now". In fact he was wrong, because "non cogito" would be self-contradictory only if it negated itself: and this no significant proposition can do. But even if it were true that such a proposition as "there is a thought now" was logically certain, it still would not serve Descartes's purpose. For if "cogito" is taken in this sense, his initial principle, "cogito ergo sum", is false. "I exist" does not follow from "there is a thought now". The fact that a thought occurs at a given moment does not entail that any other thought has occured at any other moment, still less that there has occured a series of thoughts sufficient to constitute a single self. (Ayer, Language, Truth, and Logic, pp. 62,63)

Rudolf Carnap

Rudolf Carnap

• We notice at once two essential logical misakes. The first lies in the conclusion "I am". The verb "to be" is undoubtedly meant in the sense of existence here; for a copula cannot be used without predicate; indeed, Descartes’ "I am" has always been interpreted in this sense. But in that case this sentence violates the above-mentioned logical rule that existence can be predicated only in conjunction with a predicate, not in conjunction with a name (subject, proper name). An existential statement does not have the form "a exists" (as in "I am", i.e. "I exist"), but "there exists something of such and such a kind.” …

Rudolf Carnap

• … The second error lies in the transition from "I think" to "I exist". If from the statement "P(a)" ("a has the property P") an existential statement is to be deduced, then the latter can assert existence only with respect to the predicate P, not with respect to the subject a of the premise. What follows from "I am European" is not "I exist", but a "a European exits." What follows from "I think" is not "I am" but "there exists something that thinks." (Carnap, "Uberwindung der Metaphysik durch Logische Analyse der Sprache", pg. 74)

Descartes: Cogito and S-A ontology

• 1) There is experience.• 2) Whatever exits is either a substance or an

attribute.• 3) Experience is an attribute.• 4) Attribute must belong to a substance.• 5) Therefore, there is an Ego to which

experience belongs.

Descartes

• XLIX. That the eternal truths cannot be thus enumerated, but that this is not necessary.

• We now come to speak of eternal truths. ... an eternal truth having its seat in our mind, and is called a common notion or axiom. Of this class are the following: It is impossible the same thing can at once be and not be; what is done cannot be undone; he who thinks must exist while he thinks; and innumerable others, the whole of which it is indeed difficult to enumerate, but this is not necessary, since, if blinded by no prejudices, we cannot fail to know them when the occasion of thinking them occurs. (Descartes: Of the Principles of Human Knowledge)

2) Positive part: self as a construct

Logical Positivists vs Descartes

• 1. Self is not something simple, it is something composed of elements.

• 2. Self is not know by a direct insight, but indirectly and gradually.

• 3. Self is not the Archimedian point of the knowledge, it is discovered later in the proces of the rational reconstruction.

• 4. Self is not known a priori but a posteriori, its existence is an empirical discovery.

• 5 Self is not something that exists necessarily, its existence is contingent.

Hans Reichenbach

Hans Reichenbach• Metaphysicians of all times have written much about the ego.

They have insisted that it is the cardinal point to which to attach all knowledge about the world, that the ego is a metaphysical entity known directly to ourselves, that it is a "Thing in itself" but known to us by the way of exception - and many other doctrines which under the scalpel of exact analysis turn out to be nothing but metaphors camouflaging a lack of insight into the logical nature of psychological phenomena. Our analysis of psychology furnishes an answer of quite a different type: The ego is an abstractum, composed of concreta and illata, constructed to express a specific set of empirical phenomena. (Reichenbach, Experience and Prediction, pp. 258,259)

Hans Reichenbach

• There is a long line of experience hidden behind this "I." The ego is by no means a directly observed entity; it is an abstractum constructed of concreta and illata as internal elements. Descartes's idea that the ego is the only thing directly know to us and of which we are absolutely sure, is one of the landmarks on the blind alley of traditional philosophy. It involves mistaking an abstractum for a directly observed entity, mistaking an empirical fact for a priori knowledge, mistaking a product of experience and inferences for the metaphysical basis of the world. Empiricists of all times have rightly opposed it. (Reichenbach, Experience and Prediction, pp. 260,261)

Rudolf Carnap

• The existence of the self is not an originally given fact. The sum does not follow from the cogito; it does not follow from "I experience" that "I am", but only that an experience is. The self does not belong to the expressions of the basic experience at all, but is constructed only latter, essentially for the purpose of delineation against the "others"; that is, only on a high constructional level, after the construction of the heteropsychological. (Carnap, Aufbau, 261)

Reichenbach’s no-ego-world

• As the abstractum "ego" is to express an empirical fact, we are free to imagine a world in which there would be no ego. Imagine that all people were connected, according to the salamander operation (§ 27), in such a way that everybody shared the impressions of everybody else. Nobody would then say, I see, or I fee; they would all say, There is. On the other hand, we may obtain the oppostie case by dissolving the unity of one persona into different egos at different times; if there were no memory, the states of one person at different times would be divided into different persons in the same way that spatially different bodies are divided into different persons. The concept of ego then would not have been developed. (Reichenbach, Experience and Prediction, pp. 261,262)

3) Today: Reductionism and Circularity

Three Views

• 1) Substratum (Antireductionism)• 2) Bundle (Reductionism)• 3) No-self view (Eliminativism)

Reductionism and Circularity

• I have experience, memory, body, …• I am experience, memory, body, …

• I am (my) experience, (my) memory, (my) body, … (Butler, Reid, today Campell, …)

Q-memoryShoemaker, Parfit

• I am q-remembering an experience if (1) I have a belief about a past experience which seems in itself like a memory belief, (2) someone did have such an experience, and (3) my belief is dependent upon this experience in the same way ... in which a memory of an experience is dependent upon it.

Campbell: Unowned Experience

• Ordinarily, I think of my experiences as mine. So how am I to achieve an impersonal way of thinking and talking about them? It is often supposed at this point that the reductionist must hold that experiences can in principle exist unowned, so that it is simply a contingency that all my experiences are in fact bound together as the experience of a single individual. This view has it that experiences are concrete particulars that could perfectly well exist without the person who has them. But this view does not seem intelligible; we can make nothing of the idea of unowned experiences. So the reductionist has to do without it. (Campbell 1994: 160)

Three readings

• 1) Ontological (the existence of the experience presupposes the existence of the self)

• 2) Semantical (the concept of the experience presupposes the concept of the self)

• 3) Epistemological (the knowledge of the experience presupposes the knowledge of the self)

4) Carnap’s Loop

Constructional System(of objects and/or concepts)

• Epistemological order• Rational reconstruction• Order of justification• Context of justification• Rationale Nachkonstruktion

Epistemological order

• "An object (or an object type) is called epistemically primary relative to another one, which we call epistemically secondary, if the second one is recognised through the mediation of the first and thus presupposes, for its recognition, the recognition of the first" (Carnap, Aufbau, pp. 88,89).

Rudolf Carnap

• 64. The Choice of the Autopsychological Basis• We prefer to speak of the stream of experience. The basis

could also be described as the given. But we must realize that this does not presuppose somebody or something to whom the given is given. The expression "the given" has the advantage of a certain neutrality over the expression "the autopsychological" and "stream of experience." Strictly speaking, the expression "autopsychological" and "stream of experience" should be written in the symbolism introduced in §75 as PautopsychologicalP and Pstream of experienceP. (Carnap, Aufbau, pp. 101,102)

Rudolf Carnap

• 65. The Given Does Not Have a Subject• In our system form, the basic elements are to be called

experiences of the self after the construction has been carried out; hence, we say: in our constructional system, "my experiences" are the basic elements ... the characterisations of the basic elements of our constructional system as "autopsychological", ie., as "psychological" and as "mine", becomes meaningful only after the domains of the nonpsychological (to begin with, the physical) and of the "you" have been constructed. (Carnap, Aufbau, 104)

Rudolf Carnap

• This state of affairs can be explained through an analogy: if we construct from the numbers 1, 2, 3, ... at first zero and then the corresponding negative numbers, then step by step the rational numbers, the real numbers, the complex numbers, then we shall finally characterize our startin point within the entire system of numbers by saying that we have chosen the real, positive integers as the initial elements. At the beginning of the construction, the designation of the elements as "real", "positive", and "integral" is meaningless. It makes sense only after the construction of the domains of the complex, negative, and fractional numbers, since it indicates the boundary toward these other domains. (Carnap, Aufbau, pg. 104)

Rudolf Carnap

• PexperienceP

• CexperienceC

Hans Reichenbach

• The solipsist makes a fundamental mistake: he believes he can prove the existence of his own personality. But the discovery of the ego, of the personality of the observer, is based on inferences of the same kind as the discovery of the external world. (Reichenbach, The Rise of Scientific Philosophy, pg.268)