Before I start describing my questions, I would like to draw some background on my understanding and knowledge of Descartes' ontological(metaphysical) views regarding the cogito and philosophy in general. I would also like to mention that there will be a number of connected questions and follow-up questions. I don't expect answers for all of them but I would highly appreciate if I got insights to as much of them as possible, at least just one.

So far, I understand that there has been multiple interpretations and critiques of the statement and I know so far that the statement "Cogito, ergo sum" in a more elaborate way could be written "Dubito, ergo; cogito, ergo sum" which translates to English as "I doubt therefore I think therefore I am" but I have understood in multiple occasions that this could be wrong because of the "I" component because it defeats the idea of him doubting everything because he is predefining an existing consciousness with a lot more than just thinking. I have heard that a better understanding would be to assume a "thinking thing"/"a doubting thing" as the cogito instead of "I" because through the process of Descartes' doubt that is the only conclusion we can arrive to without much confusion, but then I read an even more concise and compelling yet not-so appealing variation of "Cogito, ergo sum" i.e., "there is doubt"/"there is thought". It makes sense to actually arrive at this conclusive statement because it leaves out any uncertain/unprovable statements like existence, consciousness and proving "I".

I find this approach and conclusion quite compelling, but this is where my first conjoined question arises. When boiling the argument down to "There is thought"(on what basis, intuition or basic logic?), it seems like Descartes is trying to prove that something exists. To show that reality, was not an empty set (this was the best synonym I could find for nothing). I have a feeling he arrived at this conclusion because it is hard to prove that reality is nothing, it is intuitively easier and lazy to get to something exists in reality than to say nothing objectively exists? It felt like his cogito philosophy was there to establish a metaphysical proof for "Is there actually anything at all?/Is reality nothing?" And after he found that thought/doubt exists he extended that finding to the idea that something had to be there to receive the thought and so realized the thinking thing (the cogito) exists and somehow extended that to himself and then using the Cartesian circles (circular argument) extended it to the existence of a benevolent God and then everything else as we know it. But I am not sure at all so is this the case?

The second understanding I had was through a similar re-creation of Descartes' thought process that got him to the realization of "There is doubt". The re-creation goes something like this: "If the devil is deceiving me through the senses, experiences and everything else I know including my sense of self and consciousness and for the sake of philosophical inquiry think all of that is just deception and that I am being fed these deceptive thoughts by the devil, but I decided to doubt this deceptive reality, but then I doubt that that doubt wasn't real but was being fed to the cogito by the demon, but regardless of it being a deception or not, wouldn't matter since it would be congruent to what is actually happening since in a way the deception and objective reality converge in a sense, something just like the argument for if we make an exact simulation replica of our world to the smallest detail, would it matter if it was a simulation or not? In the same way, I understood Descartes got to the conclusion of "There is doubt" in such a way. Is this the right understanding?

The third understanding, is similar to the second, almost an extension in a way. In this thought process similar to that of mentioned directly above, Descartes doubts his reality but then continues to doubt that doubt but then continues to doubt that doubt too and continues on in this process until he deems it possible he can doubt infinitely. And in the same process he responded to the charge of circularity in his arguments: "He acknowledged that we cannot have a complicated chain of inference directly before our mind at one time. If we have proven A, figured out that that requires B, and then that B requires C, and so forth … what happens when we come to, say, Z? We can not have a clear and distinct idea of the whole proof of Z all at one time. Now, he said, we don’t need to call upon a benevolent God to assure us that any one link in the chain is valid. We have that link before us, we know that it is clear and distinct, that is enough." In this way, he could even arrive at the conclusion he made later on in his meditations, that the idea of infinite from a finite cogito points to an evidence to the existence of God. This is all speculation and so again I ask is this the right understanding?

I have a slight inclination to think that my first understanding is the right one but neither of these might be what Descartes' argument was and so if you know what it is, please explain it to me in the hopes I understand it and what the purpose of his meditations and the cogito were?

I do understand that Descartes was not genuinely carrying out the Devil argument in his head but was just a way to support his argument, I understand Descartes had previous grounds in the school of scholasticism and so the whole thing was just a mere show to prove his point, but I think Descartes' thought process has potential for absolute truth regardless of it being genuine or not, when He carried it out.

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    You can see this post: and this one: a reading of cogito is that it is not a deductive inference but an argument based on an intuition. "When someone says 'I am thinking, therefore I am, or I exist,' he does not deduce existence from thought by means of a syllogism, but recognizes it as something self-evident by a simple intuition of the mind. (Replies 2, AT 7:140)." Commented Jan 15 at 14:55
  • D's argument is from cogito, to God, to the existence of reality and our possibility of a reliable knowledge, based on celar and distinct ideas. If so, according to D, from the fact that I think and I feel I'm not licensed to infer directly that there is something real outside me that act on my sense and that my sensations are faithful witnesses of that "something". Only through the certainty (or belief) in the existence of a non-deceiving God, I can assert this conclusion. Commented Jan 15 at 14:59
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    Your first interpretation might be what Descartes should have been trying, with the benefit of hindsight and fortification against criticisms that came later, often much later. But what he was doing did have the I wrapped into it from the beginning, and was subject to those later criticisms. There is just no way to turn Descartes's actual project with its turns and flaws into a tidy argument pleasant to modern eye. You can read some interpretations and reconstructions of it in SEP, The Cogito and Doubt.
    – Conifold
    Commented Jan 15 at 15:06
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    and "objectively" is "cogito ergo sum" the base of all modern "sciences"...
    – xerx593
    Commented Jan 15 at 17:24
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    I think at a certain point the distinction between good and evil cannot be discerned, if your thought process, goes along, and, gets that far (or close!)!. Having two pushing rackets (handles/tacklers/handlers whatever you may call them), helps you steer in the right direction (if, they, is the type of thinking mechanism you call upon to be impreigned upon you). There may be others. Not sure what they would be, but a description of thought steerers and tacklers is certainly something I would like to see in AI videos on problem solving. Commented Jan 19 at 3:58

3 Answers 3


My reading is such: Descartes establishes that the sentence 'I am not' is never assertable, not that it is never true. It becomes clear once you embed it in a conditional, i.e. "Once I am not, I have died". Clearly intelligible, because assertion- and truth-conditions of a conditional "if p, then q" depend on truth and not assertion conditions of p and q. I don't mean to say that Descartes attempts to prove that we have an immortal soul with the 'cogito', but that his reasoning doesn't exactly demonstrate what he hopes to demonstrate, because it remains on an epistemic level and does not reach logical level (in other words: "we cannot doubt that X" doesn't mean "X is true"). And that might have be enough for Descartes' goals, had his other arguments been sound, it's hard to judge whether he was ever aware of the distinction.

Your reasoning for me goes as such: Descartes', by establishing that one cannot doubt that one exists, establishes that it is necessarily true that one is not fooled by the Devil to think one exists, because, if one exists, then he cannot doubt that he exists, and if he doesn't, then he cannot doubt his existence either in the virtue of non-existence. That is correct reasoning and shows what I was commenting on: the strictly epistemic nature of Descartes' argument. The objective and the subjective converge, as you say, because epistemic notions have an inherent "subjectivity" to them (it's related to the topic of semantic anti-realism - I won't go into that).

You're correct that this doesn't establish anything but Descartes not being fooled and not his existence. It's however, as I said, uncertain what he was aiming at.

One can clearly see how different is Kant's and Hegel's idealistic understanding of thought and Descartes' strictly subjective understanding of thought which the British empiricists have taken from him.

A note: Others claim the inference 'cogito, ergo sum' is supposed to establish merely the intuitive self-evidence of the claim, but I think this interpretation is at least sketchy.

  • Why do you think the inference that 'cogito, ergo sum' is just a mere intuitive self-evidence of the claim sketchy. What is your reasoning? Please explain in detail?
    – How why e
    Commented Jan 17 at 23:40
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    @Howwhye Because it's hard to understand why a inference, which is a non-immediate way of acquiring knowledge, would be the form in which a supposedly immediate, intuitive truth should be expressed in. Inference is mediated whereas intuition is immediate. If "I think, therefore I am" were an intuitive truth then it would be simply "I am" - not mediated through the "I think".
    – user71009
    Commented Jan 18 at 0:14
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    @abcga Not unless, Descartes, with his preoccupation upon ensuring the certainty of his argument would have the intuition "I am", but feel obliged to prepend such a claim with "I think" as to create the appearance of the deductive certainty of "I think therefore I am". One often embeds persuasive passages with performative-like utterances to establish one's certainty and authority pragmatically. Consider the blind use of the term 'hereby' in assertions, that strictly speaking, operate outside the context of speech coming from a social authority with the ability to wield power...
    – J D
    Commented Jan 18 at 15:54
  • When a judge says "I hereby claim that you shall comply therefore you shall", the judge prepends the speech in a pragmatic fashion to establish authority. It would be a categorical mistake to claim that the assertion is inferential at all just because the surface syntax contains 'therefore'. Sometimes, 'therefore' plays a role other than the conditional in formal reason. That is, sometimes it plays a pragmatic role. You seem to presume that the 'therefore' is actually inferential in its role as opposed to merely giving the appearance.
    – J D
    Commented Jan 18 at 15:56
  • In this case "I think therefore I am" seems more likely to express an intuition of metaphysical necessity, and therefore is outside of logical necessity. It is simply a sensible intuition upon which one's first principles can be built on. Cartesian deductive certainty starts from an axiom about the necessary connection between thinking and being, and no axiom can be said to be an inference by definition.
    – J D
    Commented Jan 18 at 16:05

There are disputes about what Descartes argument consists of. They matrix into different approaches to do epistemology.

In epistemology, there are generally three ways to establish something to be true:

  • Logical proof
  • Direct apprehension
  • Indirect inference

One can also build up a worldview from a limited set of assumed "truths", or one can instead adopt a networked worldview just based on coherence.

The philosophical understanding of how to do empiricism was not yet fully developed at the time, while deductive reasoning was well understood. Therefore, Descartes tried to cast his thinking as based on certain observations (thinking, selfhood), from which one could draw deductive conclusions, building up a worldview from these foundations.

Descartes discovered that the foundations he identified (selfhood, thinker) were just too small/narrow to do much with, so he had to cheat a bit, and argue for a kind God who would not want us deluded about most of our assumed inferences about the world.

Most of the criticisms one finds of Descartes are based on

  1. His assumptions are not REALLY unquestionable. There are Delusionists in philosophy of mind who deny selfhood and conscious thinking. Just as there are those who deny time, causation, and willing. These observed aspects of our world are not unquestionable, they are instead just very very plausible. With sufficient justification, we could reasonably reject them.
  2. Foundationalism is just too narrow of an approach. We neither have total certainty, nor have enough bandwidth from the mostly certain, to build up a full worldview.
  3. Use of advances in empiricism would have improved Descartes argument. What he really was doing was an "inference to best explanation". And if instead of foundationalism, he inferred to a coherent worldview, even if it IS still doubtable, then there would be a lot less objection to his claims.
  • What do you mean by foundationalism doesn't have total certainty? Are you saying that the foundations we start with are in fact questionable and therefore are not totally certain i.e., therefore whatever 'deductive' truth we arrive from these foundations will still not be justifiable?
    – How why e
    Commented Feb 15 at 1:33
  • The points Descartes attempted to establish with certainty have been explicitly argued against by credible philosophers. Hume disagreed that there is an I. Dennett and the delusionists argue there is no consciousness. Etc. The majority of opinion is with Descartes rather than these alternatives, but they are not impossibilities.
    – Dcleve
    Commented Feb 15 at 4:39
  • @Howwhye forgot to at you.
    – Dcleve
    Commented Feb 15 at 5:55
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    Dennett, near the end of Consciousness Explained, admitted that he was trying to do the same thing to his readers, he had constructed a set of intuition pumps that were the focus of the book and which collectively he hoped would cause his readers brains to switch to a different operating system that would no longer include the delusion of consciousness. Note Dennett argues an identity theory, that consciousness is identical to a back written narrative that is created when short term memory is written into long term memory, hence consciousness is "real" but we are deluded about its nature.
    – Dcleve
    Commented Apr 5 at 14:25
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    Whoops, autocorrect got me, "there is a something that consciousness is REALLY, not "silly""
    – Dcleve
    Commented Apr 5 at 14:28

If 400 years later we're still debating the meaning of the phrase, and have no idea if it has any real importance or relevance, then I'd argue that it boils down to wordplay which doesn't actually tell us anything meaningful, or useful about the human condition.

For reference, the theory of evolution wasn't discovered for another two hundred years after the cogito. So Descartes was steeped in a world without science, and where philosophy certainly produced coherent statements, but where we still knew very little about the world around us.

But now that we are steeped in a scientific world, consider how much more we can know about a human being than we could in 1637. Ask yourself, what impact does the cogito have compared to the knowledge we've gained in the past 150 years? The two aren't even comparable.

I think there's a tendency to revere some of these old philosophers, and memes like the cogito tend to carry on via their own inertia, but in reality the twentieth and twenty-first centuries are the only centuries we need to pay attention to vis-a-vis philosophy and science. Anything before that is a history of ideas, worth knowing to understand where we came from, but not always useful for understanding the present.

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    1. Do you want to teach schoolchildren quantum mechanics? 2. It's exactly because of the knowledged we have gained after Descartes we can finally perhaps fully understand where he erred and where he was right. It's not just a "meme", Descartes was quite a smart guy, I'd say, and if he was convinced it's significant that one cannot doubt in cogito, then it's at least worth re-evaluating. 3. 200 years? Have you heard about Lamarck or Erasmus Darwin?
    – user71009
    Commented Jan 19 at 21:57

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