Descartes’ Cogito and Hintikka



It may be surprising for general readers to hear that Descartes’ famous “cogito” argument, which runs, “I think, therefore I am”, has been the subject of controversy among academics for the past few decades.  “What is there to dispute?”, one might wonder.  “Certainly”, it might be said, “Descartes must be right in saying that, if I am thinking, I must exist.  The one seems to be sufficient evidence for the other”.

Against this line of thought has arisen the following joke which seems to have proliferated in intro philosophy courses, and runs something like this:

Descartes walks into a bar.  The waiter asks, “Would you like a glass of Burgundy?”  Descartes answers, “I think not”, and vanishes in a puff of logical dust.

The line of thinking here is that if “Cogito, ergo sum” entails that whenever Descartes is thinking he should exist, it should also entail that if Descartes is not thinking, he does not exist.

The latter inference conceals a fallacy.  To see this clearly, consider what happens when the same type of reasoning is applied to the example red–>color.  Suppose the argument is that whenever I have red I can infer that I have a color. According to the argument pattern in the joke, it should also be the case that whenever I do not have red I do not have a color.  But this is obviously a mistake.  Moreover, it is an example of an invalid argument form (P->Q, ~P/~Q) which is an involves the fallacy of denying the antecedent.

Here are the steps, for convenience:

Consider this-

(1) Red –> Color

(2) ~Red

(3) ~Color  [Fallacy of denying the antecedent]

And now compare the same pattern to the one found in the Descartes joke-

(1) I think –> I exist

(2) I am not thinking

(3) Therefore, I do not exist [again, clearly a fallacy]

By contrast, note that when the argument is put into the form of modus tollens so that it runs, “I think -> I exist, I do not exist/I am not thinking” it comes out as a perfectly reasonable inference.  However, the inference, “if I am not thinking, then I do not exist” cannot be logically derived from  “I think, therefore I am”, except by introducing a fallacy.



We have an example above of an argument in which the cogito is treated as an inference.  At first glance it seems obvious that it should be.  This assumption has been challenged, however.  In a 1962 article titled, “Cogito, ergo sum: Inference or performance?” Jaakko Hintikka argued that the argument at least need not be considered as an inference and may be interpreted as a performance.  For example, Hintikka proposed the following reformulations of the cogito to bring out its performative aspect:

  1. “I am in that I think.”
  2.  “By thinking I perceive my existence.”

By claiming that the cogito can be treated as a performance, Hintikka is aligning it with a category of other statements like “I pronounce you man and wife” or “Let there be light”.  In each case, the sentence announces the action being performed.  In the case of the cogito, or so Hintikka would have it, in the performance of the action announced in 1 & 2, one will become aware that one exists.

When viewed as a performance, the argument should not be seen (so Austin stated) as having a truth value (i.e. being true or false) but should be evaluated in term of whether it is successful or not successful.  In other words, the success of 1 or 2 depends simply upon whether Descartes (or anyone else) is actually thinking.

Hintikka’s strategy becomes evident here: by recasting the cogito as a performance, the question of its cogency becomes less a matter of searching out the linkage between thinking and existing and more a question of simply performing a certain activity.


 Hintikka’s distinction between treating the cogito as either an inference or a performance generates a false dilemma.  I would like to argue that there is a way in which, by treating “I think, therefore I am” as an entailment the cogito can be viewed as both an inference and a performance without inconsistency.

[section explaining Hintikka’s motivation to be inserted here]

But how is this possible?  It was stated above that inferences have truth conditions while performatives are either successful or unsuccessful.  How then can they wind up in the same category?  The answer is that the cogito ought to be viewed as a statement that is true or false when it is uttered by someone.  This brings in both the performative and inferential aspects as follows: the statement as an inference is either true or false, but it is such that its truth or falsity depends upon whether the act of uttering it is actually (successfully) carried out.  Whenever this is done, whenever someone utters “I think, therefore I am”, the statement automatically becomes true if the person uttering it is using the statement in a self-referential way.  The fact that no one can deny the cogito, when uttered self referentially, makes it appear as though it were a statement (or proposition) and has independent standing as a true sentence; but, in fact, it is true whenever someone utters it.  The fact that the Latin word “cogito” may also be translated as “I am thinking” may be brought in as further support for this view.

This is not a trivial point in the context of assessing Hintikka’s argument.  First and foremost, it absolves scholars of the need to debate the relative merits of a performative vs. inferential view of the cogito, since they may be viewed, as explained above as working together synchonically.  I would argue that the cogito is an example of a case where the two mutually exclusive categories may overlap and actually reinforce one another.  By viewing the statement as an utterance we do not cancel out it inferential aspect.  Indeed, it is difficult to see how that might be possible with the word “ergo” present in the very formulation of the cogito.  Hintikka can only call the cogito a performance by eliminating the word; but arguably it is present even in his reformulations (see 1 and 2 above).  Certainly, one can reason, however banal it might now seem, that if one is thinking, one, in fact, must exist; but, moreover, it seems that Descartes must have had the discovery of the linkage between the two concepts in mind when he made the cogito the starting point of his attempt at constructing a purely deductive philosophical system.





Filed under Early modern philosophy corner

10 responses to “Descartes’ Cogito and Hintikka

  1. “Cogito, ergo sum” is just not a valid argument because since a stone does not think but it still exists. But Descartes was one of the greatest philosophers & physicists as he had rationally established that humans have innate knowledge of the Creator and there has to be aether filling the space.
    Aristotle considered space as finite & absolute, time as absolute and matter as absolute thereby God had no power on space, time & matter but according to Aristotle God had the power as Prime Mover of everything (matter). Newton through his laws held that matter moves in nature not because of God but because of inherent nature of matter by which matter attracts other matter. Coming to how Newton’s Laws are wrong? From the time of Aristotle space was considered as finite & absolute till 1905. Thus at the time of Newton also same perspective of space was held.
    Now then finite space means that the universe has boundaries and according to Law of Gravitation the stars/galaxies on the periphery of the universe will be attracted towards the central universe and according to 2nd Law of Motion these peripheral stars/galaxies will accelerate towards the centre of the universe finally to collapse there. Thus finite space (the nature of space known at the time of Newton) and Law of Gravitation are contradictory. Newton assumed sun at rest but under Newton’s Laws the rest condition of any celestrial object is just not possible. Having rejected the Descartes’s aether and assumed the space as vacuum; in the 1st Law of Motion he states that objects with uniform (linear) motion faces/offers absolutely no resistance but second Law of Motion Newton states that objects pose resistance to the change in motion which he represented by inertia or mass. He assigns no physical reason to this resistance to the change in motion and it is here the philosophy/rationality was sacrificed on mathematics. Now even today physicists do not know what is mass & where it is in the particles. Adoption of Newton’s Laws was the greatest scientific error in the history of science. This was done by Newton to reject the existence of aether which was scientifically introduced by Descartes. Newton introduced irrational & incorrect laws which closed the doors of investigation into physical reality of universe especially by rejecting the existence of aether which together with nature of light contained the secrets of physical reality. It is very well known that Newton laws cannot be correct as explained by Mach & others; whatever corrections were required those corrections Einstein introduced with the help very confusing trickeries (described in detail in my article “Experimental & Theoretical Evidences of Fallacy of Space-time Concept and Actual State of Existence of the Physical Universe”; March2012). Now a paradigm of physics was defined by Einstein under which four constituents of the universe were reduced to two namely space-time concept and matter & energy transmutability where space is emergent, sum total of matter & energy is absolute & transmutable and time is interconnected with space & emergent and there is no clue as to physically what is light/radiation . Philosophically for any existence including God there are two basic requirements namely space & substance. Both of them; Newton & Einstein; had rejected aether before introducing their laws & theories and thereby closed the doors of investigation of existence of God especially as the consequence of Big Bang Theory. Transcendentalism being philosophically absurd explanation of existence of God.. Whereas aether has been shown to be existing and containing the secrets of light & time. Once aether is accepted space is again finite & absolute and filled up with aether, the electric dipoles, and it is aether through which forces of nature are transmitted as against the irrational action at a distance through fields without knowing the physicality of the fields, time is emergent & relative depending upon motion of the observer, and as humans perceive it, time is emergent and matter is not absolute but emergent.
    In brief the scenario is as under
    Aristotle:- Space- absolute & finite; time- absolute, matter-absolute, light/radiation- not properly known

    Newton:- Space, time & matter same as Aristotle; light a wave-motion with corpuscular theory

    Einstein:- Space- interconnected with time & emergent, Time-emergent & interconnected with space & relative, matter & Energy (light/radiation) is absolute & transmutable and light/radiation as wave-motion with no clue as to what is light/radiation physically

    Final state of existence:- Space-absolute & finite, time- emergent & relative depending on the motion of the observer/body with respect to aether at rest frame of reference, matter-emergent & finite, light/radiation- a electromagnetic disturbance of electric dipoles of aether creating a wave motion and all forces of nature being electromagnetic forces which is being transmitted through aether, the electric dipoles. Consequently for existence & creation of universe existence of God is obvious & evident besides being a pre-condition besides .

    Following is the list of my published articles in peer-reviewed journals & sites where these articles are available under which above-mentioned conclusions have been drawn.
    1. Experimental & Theoretical Evidences of Fallacy of Space-time Concept and Actual State of Existence of the Physical Universe (; March2012)
    2. Revised Foundation of Theory of Everything: Non-living Things & Living Things (; Sep 2010) [Revised version available on viXra, World Science Database & Journal Science Journal in my profile]
    3.Michelson-Morley Experiment: A Misconceived & Misinterpreted Experiment (; April 2011)
    4. Revised Energy Theory of Matter & Cosmology (; August 2010) [Revised version available on viXra, World Science Database & Journal Science Journal in my profile]
    5. ‘On the Electrodynamics of Moving Bodies’ by Albert Einstein is Based on Trickeries (www.elixirjournal.orgFeb.2012)
    6.Ultimate Proof of Energy Theory of Matter & Cosmology (; August 2010)
    7. Theory of Origin & Phenomenon of Life (; August 2010)
    These publications are also available on,, viXra, Intellectual Archives, ResearchGate, in my profile.

    • shafiqifs-

      I appreciate your comment and I think that, strictly speaking, the argument form A/B cannot be considered a valid one. However, whether it is an sound entailment, which was what I was arguing in favor of, is another question. It seems to me that it is a a sound when treated as an argument. It is a matter of dispute what Descartes’ intention was. Gassendi tried making an objection similar to yours that goes something like, “If I walk, then I exist”. I believe Descartes’ remark was that I can have greater certainty that I am thinking than I am walking. The remark seems to show that Descartes did want to treat the cogito as an entailment.

      • Marek

        I do not know Gassendi, but it seems that actually both acts (thinking and walking) are known to us in similar ways; so no greater certainty for either. Moreover, I believe (on pretty good arguments I might add) that that knowledge of either acts is sufficient for establishing my existence and some of my being’s unique properties, stones do not have.

      • Gassendi’s reply to Descartes is usually compiled together among the responses to Descartes’ Meditations. Without going to check them at present I would guess that the reason why D. thinks that thinking is more certain than walking is because of things like the possibility that he could be dreaming or that he could be decieved by an evil genuis or it might stem from his doubts about his body. Thinking (do D. thinks) gets past these difficulties and so it is more certain.

    • Marek

      ““Cogito, ergo sum” is just not a valid argument because since a stone does not think but it still exists.”

      Your argument involves a logical fallacy the author points out in his text. From the fact that something is not thinking you cannot infer its non-existence based on Cogito.

      So, Cogito not only has a valid argument form, but seems sound. However, it is not the ultimate explanation of either thinking or being.

      • Hi Marek-

        Here is why cogito, ergo sum is not a valid argument form:

        If you consider just the form itself, A/B, the premise does not guarantee the truth of the conclusion. For example, assume it is true that I am typing this on Saturn. It does not necessarily follow that today is Tuesday. If A/B was a valid argument form, Tuesday would follow from the truth of Saturn; but it doesn’t.

  2. The actual sense in which the “Cogito, ergo sum” Descartes meant ‘I think, therefore I am’ but what I- my living Ego. My previous comment was concerning the literal meaning of ‘Cogito, ergo sum’. Kant was a bundle of confusion to have criticized Descartes.

  3. Thorbjoern Mann

    From my unqualified perspective, the discussion seems to have gotten off to a dead-end start by only looking at the second premise in Descartes’ original argument. What he said (if I am correctly informed) was: “Dubito, ergo cogito; cogito, ergo sum.” The missing (taken for granted?) conclusion is “Dubito, ergo sum” This would be a complete and valid argument pattern:

    A –> B;
    B –> C;
    A –> C.

    So if we accept the two premises, we must accept the conclusion as true. The question is, of course: what basis do we have for accepting them? Also: Note that it states: “I doubt, therefore I exist”; not “I exist”. Accepting the conclusion “I exist” will require another argument:

    Cogito ergo sum; (If I think then I exist’)
    Cogito (I think)
    ——— —————————-
    Sum I exist

    Which, again, we should accept as true if we believe the premises are true. Accepting the first premise as true logically implies the conclusion. So the conclusion does really not tell us anything new; and the premises are as open to question as the ones above. However: According to the first (complete) argument, they are true (only?) if we doubt, — but the entire two-part argument seems to suggest we shouldn’t doubt those premises? So if we don’t doubt them, we can’t be sure we exist? That seems to be the real question. In other words: neither doubting nor thinking are sufficient and necessary conditions for existing, — just sufficient? Or not even sufficient?

    Does rambling about with fallacious argument patterns and doubtful premises qualify as ‘thinking’?

    There seem to be some instances of ‘begging the question’ involved in all this. The statement (in the linked article) ‘ …if one is thinking, one, in fact, must exist;’ is an example. It implies at the outset that there is indeed a ‘one’ who is thinking. Ergo: the question is begged. The ‘thinking’ can then be substituted with any trivial old ‘performance’. “I fart, therefore I am….” As sound a basis for a philosophical system as any.
    If I remember correctly, Descartes was holed up somewhere in Germany when he wrote that famous treatise. Perhaps he was having too much propter hoc(k)?

    • There is some good content in your comments, Thorbjoern; however, I would plead for a closer reading before deciding whether they are in fact applicable. The argument that was said to be invalid and fallacious was not Descartes, but rather the argument contained in the joke that is usually intended by philosophy teachers as a counterargument.

      Moreover, your charge of circular reasoning relies upon a quotation that is taken out of context and would seem to count as a straw man by most people’s standards. Here is the full sentence:

      “Certainly, one can reason, however banal it might now seem, that if one is thinking, one, in fact, must exist; but, moreover, it seems that Descartes must have had the discovery of the linkage between the two concepts in mind when he made the cogito the starting point of his attempt at constructing a purely deductive philosophical system.”

      It should be clear without further explanation that the force of these comments were not what you took them to be.

  4. When we are able to meditate successfully and release our thoughts for even a brief period of time, our existence does indeed continue. Your argument is well sounded, in my humble opinion.

    It’s quite interesting to me that while Descartes’ system of reasoning was his own way of getting in touch with Source and therefore solidifying his faith, later led to the growth and later substantiation of atheism embraced by so many.

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