In the third meditation, does Descartes' knowledge of his limitations, or his imperfections, lead to his conclusion that there must be something limitless, something perfect?

In his third meditation, Descartes decides that he has an idea of some attributes which he lacks:

By the word ‘God’ I understand a substance that is infinite, eternal, unchangeable, independent, supremely intelligent, supremely powerful, which created myself and anything else that may exist. The more carefully I concentrate on these attributes, the less possible it seems that any of them could have originated from me alone.

From this, he seems to argue that only an infinite substance could have given him the idea of an infinite substance:

It is true that my being a substance explains my having the idea of substance; but it does not explain my having the idea of an infinite substance. That must come from some substance that is itself infinite. I am finite.

He notes that the idea of the infinite may simply be the negation of the idea of the finite:

It might be thought that ·this is wrong, because· my notion of the •infinite is arrived at merely by negating the •finite, just as my conceptions of •rest and •darkness are arrived at by negating •movement and •light.

But he argues that this is not the case:

I clearly understand that there is more reality in an infinite substance than in a finite one, and hence that my perception of the infinite, i.e. God, is in some way prior to my perception of the finite, i.e. myself. Whenever I know that I doubt something or want something, I understand that I lack something and am therefore not wholly perfect. How could I grasp this unless I had an idea of a more perfect being that enabled me to recognize my own defects by comparison?

I'm not sure that this amounts to a knowledge of perfection. I grant that it might amount to the possibility of more perfection than Descartes, or, put another way, something less imperfect than Descartes.

So, again, why does Descartes' knowledge of his limitations, or his imperfections, lead to his conclusion that there must be something limitless, something perfect?

If it doesn't, what are the common objections?

I'm using this as my text: https://www.earlymoderntexts.com/assets/pdfs/descartes1641_2.pdf

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    This is a variation on Plato's argument for "unforgetting" of forms in Meno: how can we get to a perfect circle from those sensible distortions - it must be implanted from birth. Descartes adds a moralizing aspect to it (it is so great and perfect that it 'must' have "more reality" than humble me), infers the "perfect being" (Christian God), presumably, as the 'best explanation' for the source of perfection, and gives 'assurance' that he understands it "clearly". It is a typical example of an epistemological argument within a religious/moralistic narrative in pre-modern philosophy.
    – Conifold
    Aug 23, 2023 at 3:49
  • Even the conclusion and the word "perfection" amounts to such knowledge, his understanding surely could also be made further clearer under his own reasoning logic, not unlike Leibniz's inassignable numbers such as infinitesimals to approach the limit from a polygon to a perfect circle as his usual example to illustrate your above same conclusion... Aug 24, 2023 at 0:14

1 Answer 1


You might wanna google lumen fidei and lumen gratiae and, if you really think about it, also lumen naturale. Sorry folks, all seats are taken. You can catch the next ferry at 10:30 AM. Have a nice day and ... don't forget ta be awesome!

  • Could you say more about that? Aug 23, 2023 at 17:14
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    Fidei is just faith and Gratiae is divine grace and naturale is reason/logic, all thought ta be different ways of acquiring knowledge and lumen is light. Aug 24, 2023 at 1:31
  • Do you mean thatbDescartes doesn't think he is actually "concluding" anything, but rather having things revealed to him through lumen fidei and lumen gratiae? Aug 26, 2023 at 2:47
  • Unfortunately, I haven't read Descartes' work. However, from what I've gleaned from discussions on Cartesian skepticism, dubito ergo sum juat wasn't enough to bake the philosophical cake ... so to speak. Aug 26, 2023 at 15:54

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