Descartes imagined an Evil Demon to suggest that the external world could be a complete illusion. This Evil Demon would have the power to trick all your senses. This idea is similar to the Buddhist concept of Maya or the simulation hypothesis which is known world wide because of films such us ExistenceX, The Thirteenth Floor or The Matrix series.

Was Descartes wrong assuming that you are a thinking entity? How can you know that your thoughts are really your thoughts and not induced or created by another entity (evil demon, karma, an AI machine in the Matrix, etc)?

Is Buddha right assuming that you are not your mind and your mind creates your ego (idea of the self) which is also an illusion and you don’t need to think to know you exist? (experienced meditators know this creating huge gaps between thoughts such us in emptiness meditation)

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    It means that your mind is not at the core of your being. Your consciousness or existence is not the same as your mind. Just are just like a set of Russian dolls or a ghost in the shell, you use the computer but you are not the computer. The computer may have an agenda of its own. E.g. I'm my nationality, my race, my culture, etc. all that (ego) it's created by your mind which is not ultimately you. You are consciousness, existence you don't need a thought to know you exist. (Is that any clearer?)
    – user22051
    Apr 19, 2018 at 13:25
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    D's Evil Genius Doubt was a skeptical hypotheses assumed to "run" the argument concluding with the remark that, I “am finally compelled to admit that there is not one of my former beliefs about which a doubt may not properly be raised”. 1/2 Apr 19, 2018 at 13:31
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    At the end the only thing you now for sure is that there is some kind of consciousness experiencing something. All else is speculation.
    – vonjd
    Apr 19, 2018 at 13:31
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    @MichaelK maybe we do. It's just existence is a "no-thing" concept but our ego prevent us from seeing it. I will make a thought-experiment question in the future. Thanks
    – user22051
    Apr 19, 2018 at 14:01
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    " I will make a thought-experiment "... NO; the Matrix-like machine that is "acting you" will perfom a play showing us a thought-experiment. Apr 19, 2018 at 14:10

4 Answers 4



How can you know that your thoughts are really your thoughts and not induced or created by another entity (evil demon, karma, an AI machine in the Matrix, etc)?

I think you are skidding on 'your'. They are only not 'your' thoughts in the sense that they have been externally induced (without your knowing it). But they are still 'your' thoughts in the sense that you have them. However they came about, the thoughts are within your consciousness and hence are 'yours'.


Was Descartes wrong assuming that you are a thinking entity?

It isn't strictly correct to say that he assumed this. His first certainty was 'I think (and thinking), I exist' (Meditation 2). In the more usual form, 'I think, therefore I exist' only has a point-instant certainty. It is true only whenever it is enacted. If X enacts the thought now, and enacts it five minutes later, it does not follow (and Descartes does not think it does) that X has had a continuous existence as an entity between the two enactments.

Take a parallel with a clock : whenever it is working it shows the right time. Because it shows the right time on Monday and the right time on Wednesday, it does not follow that the clock has had a continuous existence between the two days. It may have been dismantled on Tuesday and not existed as a clock at all.

Descartes argues the case for his being a thinking entity (a continuant). It is may not be a cogent argument but it is an argument, set out in Meditations 2 and 6.


Is Buddha right [in] assuming that you are not your mind and your mind creates your ego (idea of the self) which is also an illusion and you don’t need to think to know you exist?

I am not sure about the exact line of thought here. Probably my fault. But if it is an illusion that one is one's mind and an illusion (generated by the mind) that one is an ego or self, the question naturally suggests itself : to whom or what do the illusions occur ? Who or what is 'illuded' ? There can't be an illusion without something that has it. What is the 'one' that is not its mind and is not an ego or self ? What remains to have the illusions ?

If 'one' is itself an illusion, the question recurs : to whom or what does the illusion of being 'one' occur ?


J. Cottingham, Descartes, Oxford : Blackwell, 1986, ch. 2.

Alan Tomhave, 'Cartesian Intuitions, Humean Puzzles, and the Buddhist Conception of the Self', Philosophy East and West, Vol. 60, No. 4 (OCTOBER 2010), pp. 443-457.

  • Logical mistake. I think therefore I'm. The evil demon creates the universe by tricking my senses. If the devil can trick my thoughts I may no exist. I'm conscious of the external world that is created by the demon therefore it's not mine. If i'm conscious of my thoughts it's because they are mine... Remember that there are also frmi scanners that can predict a thought before you even realise it. en.wikipedia.org/wiki/Neuroscience_of_free_will check Libet This it's just another philosophical belief that it's obsolete. As Buddha said attachment (suffering) is trouble letting go.
    – user22051
    Apr 23, 2018 at 7:47
  • I grant the possibility that I may exist only as a part of the evil demon's dream. In that case, enacting the thought 'I think, I exist', does not prove my existence because in fact I don't exist - I merely subsist as part of the dream. What do you think of that possibility ? Had you considered it ? Best - GT
    – Geoffrey Thomas
    Apr 23, 2018 at 7:55
  • As long as you experience existence (you don't need to think at all for that) you exist here and now. It doesn't matter if what you experience is a dream, illusion or computer generated world. That's the whole point of the question. Thanks for "your thoughts" :)
    – user22051
    Apr 23, 2018 at 8:00
  • That isn't quite what I said. It is not a matter of whether what I experience is a dream. The suggestion is that I 'exist' only as dreamt - only as a figment in the Evil Demon's dream.
    – Geoffrey Thomas
    Apr 23, 2018 at 8:08
  • @PbxMan, illusions are existent. Even if our world is simulation, it still exists.
    – rus9384
    May 7, 2018 at 11:01

I think that Descartes did a good thing when he said "if the Evil Demon deceives me, there is still an 'I' to be deceived." It sounds like the Buddha asks you to throw this away, since I is "no-thing".

There seems to be an inconsistency in thinking that "I" can attain emptiness, if emptiness means non-existence... clearly, if it takes work to do, then there is me, doing that work. Emptiness of own-nature then has a peculiar meaning that I have difficulty understanding.

Still, I think that each of these approaches provides an effective self-fulfilling prophecy: Descartes claims to exist; but a buddha has acknowledged (or attained) "emptiness of own-nature". Non-existence has the same power as solipsism ("only I exist") against various logical objections.

Since neither claim seems to be refutable, we are simply left with a choice! I prefer Descartes for two reasons: first, I am skeptical that my interests could still be preserved if I let go of my own nature in favor of nothing.

Second, because under Descartes' thinking I don't have to submit to objections like "if you try too hard to understand the doctrine, you will not understand the doctrine."

This is not to say that there is no place for a thinking person to submit. But it is better and more comforting to submit to a person who is worthy of submission than to submit to nothingness.

  • it's about knowing no-thingness. Something that is not in the world of form created by the mind but beyond that. Something to be experienced but not be told.
    – user22051
    Apr 19, 2018 at 15:30
  • Knowing no-thingness seems accessible by the will, and I won't push the point that this seems self-contradictory. That's why I say it comes down to a choice rather than a matter of finding the truth. It's like an unstable equilibrium. Apr 19, 2018 at 15:40
  • if you get to know no-thingness you transcend your ego and your mind. It's not solipsism it's all the opposite. It the same consciousness playing different roles in different minds and avatars in space and time. It's just the whole universe playing with itself. It is not that you only exist is that we are all one. Our mind-ego prevent us from seeing that.
    – user22051
    Apr 20, 2018 at 8:08
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    @PeterJ, I don't think it is irrational, illogical, etc. for a person to accept this doctrine, but I do think it's Un-Western, which is fine. I once heard a history person say that the best explanation will be plausible, have the best explanatory power, the best explanatory scope, and be less ad-hoc. Buddhism is definitely in the running by this metric. Apr 20, 2018 at 13:25
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    "For there is suffering, but none who suffers; Doing exists although there is no doer. Extinction is but no extinguished person; Although there is a path, there is no goer." - Visuddhimagga XVI 90. There is indeed an inconsistency in thinking any 'I' can 'attain' emptiness
    – CriglCragl
    Apr 20, 2018 at 19:29

I suppose some of the distinctions I'm about to make depend upon the strand of Buddhist thought to which you're referring. I'm going to approach this from an ancient Indian Madhyamaka perspective.

Was Descartes wrong assuming that you are a thinking entity? How can you know that your thoughts are really your thoughts and not induced or created by another entity (evil demon, karma, an AI machine in the Matrix, etc)?

It isn't that Descartes is wrong about the thinking part of the 'thinking thing' assertion; his assertion is flawed, according to Madhyamaka Buddhist thought, because, within that assertion, Descartes is already presupposing real existence of essence -- a claim about self's thinghood, which is a claim about the ultimate truth of self. But, since self can't be understood as independently arisen, it is therefore empty (of ultimate truth.) It should be noted that this does not imply a theory of self cannot be conventionally/provisionally true.

Is Buddha right assuming that you are not your mind and your mind creates your ego (idea of the self) which is also an illusion and you don’t need to think to know you exist? (experienced meditators know this creating huge gaps between thoughts such us in emptiness meditation)

Again, according to the tradition I'm reading in, Buddha demonstrates the illusory of self in order to show such notion is ultimately empty, not to argue against the 'thinking' aspect. I think the distinction I'm drawing here is best understood in terms of the two truths.

It is important to note that emptiness of essence does not preclude provisional existence or truth. Nagarjuna even argues that emptiness is, itself, empty.


Descartes is at very different purposes with his Evil Demon than the role of maya or the simulation hypothesis. Descartes places primacy on mental experience, which makes the regularities in the material world problematic - which he accounts for with the mentality of a deity, an inevitable consequence of substance dualism (but not property dualism). It may appear that theism is not essential to Cartesian dualism, but it makes the unity of the external world at the very least require the 'god of the philosophers', or deism. Materialism or physicalism, places primacy on material experiences, which makes accounting for subjective experience or qualia problematic, resulting in the Hard Problem of Consciousness.

Maya is translated as 'pretence' or 'deceit', a negative mental quality like lust. In Buddhism, conventional experience is always founded in misconceptions, is always a kind of dream or illusion. There is no other kind of subjective or self-identifying experience. Delusion, craving, suffering, and the arising of causal chains and identity, are seen as of a piece, in the chain of dependent arising. There is no true unity in the external world, except in what is regular in the nature of minds and their shared history together or codependent arising.

Descartes says there is this thinking I, which he already makes assumptions about the capacities of - such as access to apriori concepts. Buddhism says, whatever locus of experience there is, that is the self. And then by reflection and direct experiencd, identifies that there being a locus for events is in fact an illusion. The former cannot deal with the Private Language Argument. The latter prefigures it (imho).

"David Chalmers has argued that we should consider the 'simulation hypothesis' not as a skeptical hypothesis that threatens our having knowledge of the external world but as a metaphysical hypothesis regarding what our world is actually made of. " http://philosophycommons.typepad.com/flickers_of_freedom/2014/08/the-case-for-libertarian-compatibilism-a-brief-overview.html (discussed here Are we living in a simulation? The evidence). This can be used to reconcile subjective mental experience, and the experience of a shared external world, such as through the Peer-To-Peer Reality idea - very like Indra's Net, a model of mind and reality shared by Hindu and Buddhist thinkers.

So, Descartes is wrong not because he can't be sure they are his thoughts, but because he can't have the conceptual notion of a self without an inheritence, without a prconception of a shared and collectively generated reality. In Buddhism this is called karma, and can be analysed for instance as Eight Consciousnesses (very similar to Aristotle's three souls).You thinking about it, is you being a self - so using thought can never unpick your being or negate any existence. It's like using a telescope to try and look at itself. In meditation you first try and see how clear is the lense, then about why you feel motivated to turn the telescope to certain things, then you put the telescope down and see what happens. This is not using thoughts to look at thoughts, creating thinking-self. It is observing, settling, observing, just watching what your mind does without pushing it anywhere.

  • Thank you for your contribution but I think you are wrong in some aspects. I have been to some buddhist and yoga meditation centers and they all say the same thing. "If you can observe it it's because it's not you" If you can observe your house, your car, your flag, clothes, your body and even your own thoughts it's because it's not you!" you are just "the watcher" the rest is Maya. At least that's what it's told in those places. I wonder why the Dalai Lama or similar have not addressed this question. Perhaps a good deal of western philosophy is just flawed but we cannot accept it.
    – user22051
    Apr 22, 2018 at 12:05
  • That restates exactly what I said.
    – CriglCragl
    Apr 23, 2018 at 12:42

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