Ash Catton

PhD Candidate, Clinical Psychology Student

Descartes’ Cogito: A Discussion

August 24, 2018

In his Meditations on First Philosophy, Descartes presents a possible foundation for a framework of knowledge. Rooted in subjective experience, the cogito is the first self-evident truth upon which all other truths can follow. In §1 of this essay, I will outline the process Descartes undergoes to arrive at the cogito. In §2 I will explain why the cogito is best interpreted as an appeal to intuition rather than a logical proof. However, in §3 of the essay, I will argue that it is a mistake to think of the cogito as the result of any sort of active internal narrative (“thinking”) but rather as a state of passive awareness – given that Descartes cannot justify the attribution of ownership for the thoughts he experiences. I will conclude that rather than acting as the first step for a larger framework, the cogito is a dead-end and not a suitable candidate for an epistemological foundation.

1      The Cogito Explained

In the Meditations, Descartes tells us that he had grown up believing the truth of many falsehoods and had yearned to one day perform the task of mentally putting aside all his beliefs to start again.[1] Thus, the First Meditation sets the stage for his doubt, wherein he realises that as his capacity for reasoning is not infallible, that any beliefs he arrived at in this way may not all be as certain as they may seem. The Second Meditation picks up from this point, and its purpose is primarily to find a single clear self-evident truth that is immune to the fallibility of his reasoning capacity. To illustrate this point, Descartes presents us with the analogy of the malevolent demon which serves both as a symbol, and constant reminder of the myriad ways in which our reasoning capacity can commit errors.[2] He cloaks this demon with the power to muddy the waters of his rational deliberation, so that the inferences he makes about the world are false.

At this point Descartes realises that even if the demon is manipulating every inference he makes, he knows that he must be something if he is to be deceived. Thus, the second part of this Meditation is to find that single factor to associate his identity (the ‘I’) with. He achieves this through a process of elimination, where anything that can called into doubt is eliminated so that what he is left with is “…certain and unshakeable.”.[3] After eliminating those inferences drawn from the external world, he concludes that the act of thinking which he is undergoing is the only thing he can be certain of. This subjective factor is the cogito. He realises that he exists as something that thinks and while he continues to think, he necessarily exists.

Descartes concludes this Meditation by exploring what sort of thing the ‘I’ is. Knowing that he cannot be certain that the cause of his sensory perceptions is certain, he does know that the experience of those perceptions is real. However, he also realises how little the mind relies on this raw data in making its judgements, and he illustrates this point by manipulating a piece of wax that he has in front of him.[4] He toys around with it in its hard form then melts it with a candle and realises that those properties that may have defined it previously no longer apply to its molten state. Yet he realises that he still perceives it to be the same object despite there being nothing in his raw sensory data to indicate that it remains the same object. Thus, he realises that his perception of ‘conservation of substance’ lies not in the object itself but is the result of a mental inference – which means that it is vulnerable to the manipulations of the deceiving demon. However, he maintains that he must exist if he is perceiving the wax.

2      Interpreting the Cogito

Despite the cogito generally being expressed in the form cogito ergo sum (“I think therefore I am”), the form of the argument presented in the Meditations is notable for not containing ergo. This means that it may be a mistake for it to be understood as a syllogism. This is further evident if one tries to reduce the Second Meditation into premise form, as it becomes apparent that there are necessary premises which Descartes does not state. At least one commentator has suggested that if this passage was intended as a syllogism, Descartes would need to specify how ‘thought’ is an active process engaged by some object, as well as specifying basic logical principles.[5] Given that logic itself has not yet been established, Descartes cannot claim them as part of a formal argument. Popkin states that the cogito is the “conclusion of doubt” rather than a syllogism, which means Descartes must be appealing to something other than logic.[6]

Descartes has thrown away many of the traditional forms of knowledge gathering and inference generating that he had relied on previously. Essentially, anything that originated outside of himself has been rendered doubtful. This leaves him with an appeal to something within ourselves, such as intuition, but it must be obvious enough to survive the deceitful demon’s tactics. Thus, the cogito has been described as a ‘self-evident inference’.[7] This is something that can be arrived at a priori yet clear enough to be accepted by his readers. Cottingham has noted that the structure of the Meditations show that it was constructed to “conform to objective patterns of meaning”.[8] Thus, the layout of the Second Meditation is such that it shows his readers how to see the truth of the cogito for themselves. Unfortunately for Descartes, not everyone agreed that the truth of the cogito was arrived at so easily.

3      The Problem of the ‘I’

Descartes believes that he is a thinking thing. The leap he makes from recognising that there are thoughts, to his conclusion that he is a thinking thing, is the source of great trouble. However, it is not due to the reason that some would suggest. For instance, Prado states that thought existing without a mind is not a logical contradiction.[9] It would be a mistake to suggest this as the basis for an objection given that we have not yet established logical principles. What is needed to strengthen this objection is to cast doubt on the attribution of ownership of the narrative of thought (i.e. the meditation itself) that Descartes claims are his own thoughts. In other words, we must show that the human experience of mental narrative can be manipulated by the deceitful demon.

3.1     A Sketch of the Problem
Bertrand Russell wrote “…[Descartes] nowhere proves that thoughts need a thinker”.[10] Again, we shall not charge Descartes with violating logical principles. However, this is sufficient to seed some doubt on the notion that the move from ‘there are thoughts’ to ‘I am a thinking thing’ is part of a self-evident inference. However, the thrust of this objection may turn on whether the cogito is an inference at all.
3.2 Ego Faciendo: Cogito as Performance
Descartes concluded that as he continued to think, he must exist as something that thinks. This suggests that the cogito is some sort of active process, and it is this possibility that leads to the suggestion of the cogito as a performance. In his paper on the subject, Hintikka shows the existential inconsistency evident in a person proclaiming, “I do not exist”.[11] As this inconsistency only works in the first person and in the present tense, and that the Meditations were written this way – it opens the door to the possibility that the cogito is meant as the conclusion of a performance. This means that “I exist” is necessarily true every time I utter it, and the truth of this conclusion is available to anyone else by doing the same.

It has been objected that this argument takes a wider definition of ‘thinking’ than Descartes might have intended, given that other words would have been more appropriate to capture such a delicate meaning.[12] However, Hintikka’s solution also depends upon the infallibility of the attribution of agency made to the performance. 

3.2.1       False Attribution of Agency/Ownership
Descartes outlined that the human mind can commit errors when it makes judgements and inferences. Recall that his solution was to frame the cogito as an appeal to intuition where the reader can just grasp the truth and certainty without having to seriously engage the rational mind. It has been suggested that basic logical principles like the self-evident modus ponens similarly appeal to some sort of core subjective assent.[13] Despite his attempt to remove all those beliefs which were obtained from potentially fallible means, I believe the attribution of ownership Descartes makes by claiming the thoughts as his own also fall into this category.

The advantage of analysing the cogito in the Twenty-first Century is that it allows us to lend some empirical support to Descartes’ deceiving demon. Firstly, consider the possibility that the demon could cause us to think we had performed certain physical acts that we had not. It has been shown that stimulating certain parts of the parietal cortex can result in beliefs in the subject that they had performed certain movements when they had not.[14] This alone does not pose any problem for Descartes as he has already discarded sensory input as a candidate for certainty. But this does show that beliefs can be implanted into our consciousness by external sources that remain outside of our awareness. Thus, it remains possible that the desire for certainty which leads to the cogito was deliberately implanted by the demon.

Furthermore, some studies have also shown that it is possible to make a false attribution of the ownership of actions performed by other people.[15] Thus, one study from 1997 of schizophrenic patients illustrates this point well.[16] Thirty schizophrenic patients and control subjects were tasked with performing specific hand movements without direct visual access to their hands. The only visual feedback the subjects received was via television screen, and for some the feedback was of a confederate’s hands performing the same task. The results showed that the schizophrenic patients were more likely to incorrectly claim the alien hands as their own, revealing a deficit in the ability to recognise one’s own actions. 

While he did not have the benefit of modern psychology to draw upon, this does pose a problem for Descartes’ enterprise. If the brain can be stimulated in a way that forms and influences our conscious processes including the potential to make false attributions, there emerges the possibility that the internal narrative that Descartes presents is not his own. Recall the possibility that the demon can manipulate Descartes thoughts as part of a wider plan. We now have some doubt that the cogito, whether performance or inference, is the product of his own thinking. This means that the cogito cannot involve any active process of thinking and must involve some more primitive mental phenomenon.

3.3      Ego Conscientiam: Cogito as Awareness
Descartes’ subtracted all that was the product of a potentially fallible inference to be left with raw, certain subjectivity. Unfortunately, Descartes’ internal narrative is similarly susceptible. In other words, we must now look upon conscious thought as another form of sensory experience whose source we cannot be certain of. However, even if we are not certain that we are in control of our conscious mental processes, we can subtract them to be left with passive awareness. This takes the cogito one step back and relies on a wider conception of thinking that is compatible with Kenny’s study of Descartes’ use of the term, despite his objection of Hintikka’s excessively wide definition.[17] Indeed in the Second Meditation, Descartes does provide a brief list of what he considers ‘thinking’ to entail and they include processes like the experience of sensory perceptions.[18] Elsewhere, he associates thinking with being “…immediately aware…” – These are things not normally associated with the term ‘thinking’ in English conceptions.[19] Newman notes that Russell underestimated the subjective character that introspection presents us with, and we have just illustrated why this is so.[20] Unfortunately, this presents us with a dead-end rather than a promising first step in a framework for knowledge. All that we can be certain of is that we are passively aware. Indeed, it has been noted that Descartes’ standard for certainty was set too high even for his own project.[21]

4      Concluding Remarks

Descartes’ cogito is a well-conceived device that is the product of an extreme form of doubt. We have not been able to support either the syllogistic nor active performance interpretations of the cogito, given the lack of support for both. However, we have been able to salvage Descartes cogito from the previously unentertained possibility that the internal narrative which gives rise to it is not Descartes’ own thought. By restricting the cogito to passive awareness alone, we have found that there is no room for Descartes to proceed in building a framework of certainty. This renders the cogito unsuitable for the task that it was conceived to fulfil.

Works Cited

Blakemore, Sarah-Jayne. "How We Recognise Our Own Actions." In Downward Causation and the Neurobiology of Free Will, edited by Nancey Murphy, George F. R. Ellis and Timothy O'Connor. Berlin: Springer-Verlag, 2009.
Cottingham, John. Cartesian Reflections: Essays on Descartes's Philosophy. Oxford: Oxford University Press, 2008.
Descartes, Rene, and John Cottingham. Meditations on First Philosophy: With Selections from the Objections and Replies. New York: Cambridge University Press, 2017.
Desmurget, M., K. T. Reilly, N. Richard, A. Szathmari, C. Mottolese, and A. Sirigu. "Movement Intention after Parietal Cortex Stimulation in Humans." Science 324, no. 5928 (May 8 2009): 811-3.
E, Daprati, Franck N, Georgieff N, Proust J, Pacherie E, Dalery J, and Jeannerod M. "Looking for the Agent: An Investigation into Consciousness of Action and Self-Consciousness in Schizophrenic Patients.". Cognition 65, no. 1 (1997): 71-86.
Hintikka, Jaakko. "Cogito, Ergo Sum: Inference or Performance?". The Philosophical Review 71, no. 1 (1962): 3-32.
Kenny, Anthony. Descartes: A Study of His Philosophy. New York: Random House, 1968.
Newman, Lex. "Descartes' Epistemology." In Stanford Encyclopedia of Philosophy, edited by Edward N. Zalta, 2014.
Popkin, Richard H. The History of Scepticism from Erasmus to Descartes. Assen, Netherlands: Royal Van Gorcum, 1960.
Prado, C. G. Starting with Descartes. London: Continuum, 2009.
Russell, Bertrand. History of Western Philosophy. Abingdon, Oxon: Routledge, 1946. 2006. 1946.
Sarkar, Husain. Descartes' Cogito: Saved from the Great Shipwreck. Cambridge: Cambridge University Press, 2003.


[1] Rene Descartes and John Cottingham, Meditations on First Philosophy: With Selections from the Objections and Replies (New York: Cambridge University Press, 2017), 15.[2] Ibid., 21.[3] Ibid.[4] Ibid., 25-26.[5] Husain Sarkar, Descartes' Cogito: Saved from the Great Shipwreck (Cambridge: Cambridge University Press, 2003), 184, 86.[6] Richard H. Popkin, The History of Scepticism from Erasmus to Descartes (Assen, Netherlands: Royal Van Gorcum, 1960), 187.[7] Lex Newman, "Descartes' Epistemology," in Stanford Encyclopedia of Philosophy, ed. Edward N. Zalta (2014).[8] John Cottingham, Cartesian Reflections: Essays on Descartes's Philosophy (Oxford: Oxford University Press, 2008), 118.[9] C. G. Prado, Starting with Descartes (London: Continuum, 2009), 73.[10] Bertrand Russell, History of Western Philosophy (Abingdon, Oxon: Routledge, 1946; repr., 2006), 519.[11] Jaakko Hintikka, "Cogito, Ergo Sum: Inference or Performance?," The Philosophical Review 71, no. 1 (1962).[12] Anthony Kenny, Descartes: A Study of His Philosophy (New York: Random House, 1968), 44.[13] Newman, "Descartes' Epistemology."[14] M. Desmurget et al., "Movement Intention after Parietal Cortex Stimulation in Humans," Science 324, no. 5928 (2009).[15] Sarah-Jayne Blakemore, "How We Recognise Our Own Actions," in Downward Causation and the Neurobiology of Free Will, ed. Nancey Murphy, George F. R. Ellis, and Timothy O'Connor (Berlin: Springer-Verlag, 2009), 148-9.[16] Daprati E et al., "Looking for the Agent: An Investigation into Consciousness of Action and Self-Consciousness in Schizophrenic Patients.," Cognition 65, no. 1 (1997).[17] Kenny, Descartes: A Study of His Philosophy, 44.[18] Descartes and Cottingham, Meditations on First Philosophy: With Selections from the Objections and Replies, 24.[19] Appendix to Replies to Second Objections, cited in Kenny, Descartes: A Study of His Philosophy, 44.[20] Newman, "Descartes' Epistemology."[21] Popkin, The History of Scepticism from Erasmus to Descartes, 199.


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