Am I Certain That I Exist?

Am I Certain That I Think?

Descartes wanted to build human knowledge on a foundation of certainty. He thought the Cogito provided an instance of certainty, and many have agreed (Montaigne was there before him). Critics have argued that the conclusion of the Cogito doesn’t follow from the premise (the Lichtenberg objection). However, the premise itself is seldom questioned; it at least is certain, whether or not it entails the existence of a thinker. But is it certain? First, we need to ask what it means: when I say “I think” what proposition am I asserting? Does it mean the same as “I am a thinker”? And does that imply “I am a rational thinker”? Am I asserting that I think rational thoughts?  But there are two problems with this interpretation: (a) how can I be certain that my thoughts are rational and (b) how can I be certain that I have thoughts plural? What if there is a brain disease that renders my thought processes irrational while giving me the illusion that they are rational? I can’t rule this out with certainty. And how can I be certain that I have thoughts in the plural given that this will require a series of thoughts over time? I can’t be certain I have had thoughts in the past since memory is fallible, and the existence of future thoughts is even less certain. So, should “I think” be read as “I have a thought now, which may or may not be rational?” But is it possible to have only one thought and it be completely irrational? Would that even be a thought? Thoughts occur in series of linked thoughts (“temporal holism”), and their title to being thoughts surely depends on some degree of conformity to rationality, however minimal. But these requirements are not open to certainty. In addition, thoughts in the ordinary sense have intentionality, but is that open to certainty? Couldn’t I be having thoughts about nothing—how can I be certain that my thoughts are aboutthings? What thought is it that I am supposed to be certain I am having? Is it the thought that it is (say) raining in Miami now? But how can I be certain my thought is about Miami and rain—what if I am a brain in a vat and content externalism is true? Is it the thought that I think (“I think that I think, therefore I am”)? But then we are back with the problem about rationality and thought plurality. It looks as if we need to retreat inwards a step: “I seem to think, therefore I am”. We thus cancel the proposition that I really think and maintain more modestly that I appear to myself to think. This falls far short of the original Cogito in that it concedes that I cannot be certain that I think: that proposition cannot be the premise the Cogito works with. We can gloss “I seem to think” as “I may be thinking now but maybe I am not—it only seems to me that I am”. Is this strong enough to get the conclusion we want? It seems like a very flimsy foundation for erecting a tower of certain knowledge. And if we are to retreat to a “seems” version of the premise, why not say simply “I seem to exist, therefore I exist”? For, if we can’t appeal to an unqualified “I think” but must restrict ourselves to “it seems”, then we may as well do it straightforwardly and honestly—”I seem to myself to exist, therefore I must exist”. But that looks like a straight non-sequitur: how can my existence follow from the mere appearance that I exist? Don’t we need the existence of something real to get anywhere—as in the existence of real thoughts? How can seemingentail being? Certainly, this revised Cogito looks weird and fishy compared to the classic version—hardly self-evidently true. This impression is confirmed by raising another skeptical possibility, namely that we can’t get existence out of seeming existence—out of the mere impression of existence. Nor can we get it out of the mere impression of thoughts as opposed to real thoughts. Suppose you are Meinong and believe in different kinds of being, subsistence and existence: maybe you can derive self-existence from genuine thought-existence, but how can you derive it from mere appearances of existence? Surely subsistence could seem like existence, so it may be that the self you derive from “I seem to exist/think” is just a subsistent entity not an existing one (like a hallucinatory golden mountain that looks real). In order to rule this out you would need to refute Meinong by claiming that all subsisting objects are existing objects—or else the Meinongian will insist that the conclusion could only be that I have some sort of being. In other words, the seeming premise only licenses an inference to “The subject of this seeming has being of some sort”. To be more specific, how can I be certain I am not a fictional character? It can seem to a fictional character that he thinks and exists, but he is not thereby a thinking existing being like you and me (as we believe, at any rate).[1] Or if you hold that fictional characters really have existence, then the new Cogito has to conclude “Either I exist in the real world or I am a character in fiction”—not quite what Descartes was hoping for. The problem is that seeming is too weak to give (real) being, but we can’t justify the original premise that asserts certainty about the existence of thoughts (thinking). Can we assert the existence of real seemings? If so, we might be able to move to real subjects of seemings. But of course, there can be fictional seemings: it can seem to a fictional character that things are thus-and-so. I therefore need a way of showing that my seemings are real, but all I am entitled to is that they seem real. We are now at an argumentative stalemate, whereas the original Cogito at least purports to start from a premise about incontestable reality, viz. the known reality of thoughts and thinking. The idea was that we can know with certainty that thinking really exists and then move from this to the existence of the self. But it now turns out that only a “seems” premise is acceptable, which undercuts the move to an “is” conclusion (“I exist”). So, Descartes needs his version of the Cogito and not the weakened “seems” version: if the argument were equally good under the “seems” interpretation, he could have simply said “I seem to exist, therefore I exist”—which looks like a blatant non-sequitur.[2] But the original version is open to skeptical doubt about the premise itself, not merely about the validity of the inference. The lesson is that trying to base human knowledge on certainty is hopelessly quixotic and should not be attempted (unless we stick with the ordinary man’s use of “certain” and forget about philosophical skepticism). Or to put it differently, an epistemology of science should not be in the business of refuting skepticism. It will only take a sound beating if it chooses to take on the skeptic (like Don Quixote himself fighting foes far more powerful than him[3]). Descartes clearly had problems with his attempt to prove the external world (what with the ontological argument and God’s supposed non-deceptive nature), but in fact the problems begin much further back with his attempt to find at least one indubitable proposition. It is the whole Cartesian project that is at fault. Certainty is a false god.

[1] This is exactly the situation of two characters in Sophie’s World by Jostein Gaarder (1994): they think they are real but discover that they are characters in someone else’s work of fiction. Fictional characters cannot use the Cogito to prove they are real.

[2] There is also the problem that in order to know that it seems to me that I exist, or that I seem to have thoughts, my seeming must have intentional content; but how can I be certain that it does, given that this doesn’t depend solely on my inner state? The skeptic will argue that my seeming might not have the content I take it to have, if I am a brain in a vat or sufficiently mentally deranged or confused. Episodes of seeming can be as subject to skepticism as thoughts are with respect to their content. Things are not as simple as Descartes supposed.

[3] Don Quixote de la Mancha cuts quite a philosophical figure: even after a series of terrible drubbings he refuses to abandon his absurd delusions, despite the entreaties of Sancho Panza (the voice of common sense). He is the living embodiment of human error—of life inside Plato’s cave. Descartes is quixotic in the precise sense that he keeps fighting for his misguided ideals even when he is clearly outgunned by the evil demon; he is too entranced by the romance of complete certainty. There is a nobility to this, but it’s none too realistic.

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9 replies
  1. Jim Ramsay
    Jim Ramsay says:

    I actually prefer an even softer version of the cogito: “I experience.” I agree I can’t be certain of the cardinality of previous thoughts or the rationality of any thoughts, or even ownership of the thoughts… I could be a passive subject just watching someone else’s movie.

    But doesn’t “I seem to think/exist” still necessarily presuppose an “I” who can “seem”? (Likewise “I experience”, the experiencer?) Existence, at least in some sense of the word, is a necessary assumption of any self-reflection. Thus I can always be certain that I “exist” within some context, but whether this context is a “real” world or a “fictional” one is inaccessible to me and irrelevant to this one tiny spec of certainty.

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    • Colin McGinn
      Colin McGinn says:

      But if it only seems to me that I exist, then I might be a fictional character, and fictional characters don’t exist; or if we choose to say they do, we get only a very attenuated kind of being out of the Cogito–not what Descartes was aiming for. We just get the idea of a grammatical subject or a Meinongian intentional object.

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      • Jim Ramsay
        Jim Ramsay says:

        I agree that Descartes was aiming too high. The certainty I think I can justify is just in some Meinongian or context-dependent kind of existence. Any further claim as to the nature of that context, be it a physical reality, a simulation, an idealist mental state, or a fictional story, is a completely orthogonal (and I think unresolvable) question.

        But certainty in that “attenuated form of being” is still certainty. When you ponder whether “I might be a fictional character”, I read that not as you doubting whether you exist, but questioning the ontology of the context of that existence.

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        • Colin McGinn
          Colin McGinn says:

          It is certain that the sentence “I seem to exist” contains a subject term and can refer to an object of thought (like Santa Claus), but such intentional objects don’t exist in the sense that believers in the Cogito would like. I don’t believe that existence is a context-dependent property: there is no context in which Santa Claus exists (though he can be believed to exist).

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  2. Paul Reinicke
    Paul Reinicke says:

    Indeed. Have any one of us ever had even *one* actual thought? That is, what is thought and what is thinking, if — as Robert Sapolsky argues in his book Determined (and I would agree) — everything we think of as thinking is nothing more than the result of countless causational factors all swirling together and beyond our control?

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      • Paul Reinicke
        Paul Reinicke says:

        Hmm. My thoughts are going in several directions at once. For example, what is meant by “we,” what is meant by “think,” what is meant by “compare perceptions and emotions.” But I guess what I’m really getting at is if thinking is determined by factors beyond our control then is what we think of as thinking really thinking? If you lightly tap a knee with a reflex hammer and it moves, is that knee “thinking?” Similarly, if a brain is lightly “tapped” with causational factors causing it to think ‘x,’  is that really what we generally regard as “thinking?”

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        • Colin McGinn
          Colin McGinn says:

          Is perceiving with the senses really perceiving if it is caused by a stimulus over which we have no control? Yes. Same for emotions, beliefs, desires, pains, and so on. Why should thinking be any different?

          Reply
  3. Giulio Katis
    Giulio Katis says:

    I just reread Part Four of Descartes’ Discourse on Method. It is interesting to watch/listen in slow motion (so to speak) what is going on in his mind. It is a very intimate moment he shares with us (he expresses his concerns up front about sharing this experience). It is remarkable, a privilege really, that we can listen in on this after all these centuries.

    This is what seems to me to be going on (behind the words). Even the most ardent doubter cannot doubt their own ability to doubt, otherwise they will cease to exist as a doubter. This does not mean cease to exist altogether – just the grasping to their identity as a rational doubter would have to cease. But, somewhat ironically, Descartes does not seem to recognise this. I do think though he had a flash of psychological insight, but then this got lost in a fixation on the words of thought. That flash, I suspect, was not a conceptual insight about thinking and the nature of existence, but was an unmediated recognition of one’s capacity to decide on one thing, that one thing being one’s capacity to recognise.

    He writes: “And having noticed that there is nothing at all in this I think, therefore I am that assures me that I am speaking the truth, except that I see very clearly that, in order to think, it is necessary to exist, I judged that I could take as a general rule that the things we conceive very clearly and very distinctly are all true, but that there is merely some difficulty in properly discerning which are those that we distinctly conceive.”

    This is not an argument. I take it to be a recounting of some form of vision (direct psychological insight) of what it means to be in a state of decisive confident knowledge. And presumably for Descartes this was the meaning of existence. I note that this actually requires no (articulated, logical) thought per se – it is a psychological state. Confident knowledge of the world, a world that may contain an actual thinking Descartes, would be something else. I take this to be part of the point you are making in this post.

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