1/8. Descartes 3: Proofs of the Existence of God

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1 1/8 Descartes 3: Proofs of the Existence of God Descartes opens the Third Meditation by reminding himself that nothing that is purely sensory is reliable. The one thing that is certain is the cogito. He now describes the fact of knowing the cogito as a clear and distinct mental perception and on the basis of this description states that everything perceived clearly and distinctly will be true. However whilst this appears to provide us with a criterion for understanding what is true and what is not it is not immediately evident how to apply it given that many things appear to us be certain when in fact they are capable of being doubted. Descartes now reminds us that the perception that there exist things that are external to the mind is one of the matters that always previously struck us as similarly certain. He points out however that he is not denying this even now. That is, he is not denying that things appear to be external to him. However, the correspondence of this idea to existent things is what is open to doubt. Another area of apparently secure previous knowledge concerned mathematical and geometrical matters. Descartes now remembers that whilst the ideas of mathematics and geometry struck him as clear and distinct that what rendered them doubtful (in the course of the First Meditation) was the notion that God might exist and in existing might make me be deceived constantly when I thought that I had these ideas clearly in mind. There is no necessary reason to think that such a God exists of course and because of this Descartes describes this as a metaphysical doubt. Whilst the doubt does rest on adopting a hypothesis this hypothesis

2 2/8 is one that there are no good reasons as yet for ruling out. The God that exists, given that he is all-powerful, could also be deceiving me. However, it is also worth pointing out that when Descartes looks at the things themselves which I think I perceive very clearly he is convinced by them and he includes in this statement of conviction simple mathematical truths such as 2+3=5. This suggests that whilst he is thinking of mathematical truths they seem true but when the metaphysical doubt concerning God is introduced they appear false. Hence, the immediate response to mathematical truth is an affirmative one. Still, this is not sufficient to enable us to rescue these truths, as the very possibility of the hypothesis concerning God being true is enough to unsettle these apparent truths and render them insecure. Before examining the question of whether this notion of God is really a clear and conceivable one Descartes first takes the precaution of examining the question what types of ideas can be said to be capable of being true or false. Some thoughts are basically just images of things and as images cannot be false. That is, when I think I have an image of a goat then this is because a goat does appear to be before me in some form so I do have an image of the goat when I think I do. However this does not entitle me to say that there actually is a goat external to me that corresponds to this image. For this involves not just the notion that there is an image of a goat but also that there is a goat and to make this step is to make a judgment about the image that I have in front of me. Hence if I make a mistake about

3 3/8 something, that is, if there is something that is a thought that is capable of being false, then this must be a judgment and only judgments, not images, are capable of being false. Why then do I make the judgment that what appears before me is in truth external to me? One reason is that the things that I judge to be external to me do not depend on me in the sense that, for example, I do not choose whether something appears in front of me. What appears to be in front of me impresses itself on me and I cannot, by my thought, alter it. Hence it appears to be independent of me. However this is not a sufficient reason for thinking that it really is independent of me as when I am dreaming images appear before me that I cannot alter and change as I would wish and that force themselves upon me whether I would wish to be faced with them or not. And even if a thought about an object came from the object in question then this does not mean that the object corresponds to the thought about it. So my idea of the sun if dependent on perception would represent it as small whilst if I reason about the sun I am aware of it as large and yet my perception of the sun is commonly said to come from the sun. So even if ideas of objects do emerge from these objects that is not a sufficient reason for thinking that these ideas are correct. Lets move away from considering objects in relation to perception then since this way we seem to get no closer to a reason why we think that there exist objects external to us. If we attend instead to our thoughts and examine their nature we should find that we can make distinctions based on

4 4/8 reason alone without reference to the senses; for example, the distinction between substance and accident. Everything that appears to me, that is, appears in modes and manners. So, an apple appears to me as coloured, as weighing a certain amount, as tasting a certain way, having a certain smell and as producing a certain type of sound if tapped. All these modes of appearing are what philosophers term its accidents. But underneath all the accidents is something to which they belong and this is what we term the substance of the apple or in other words for us to describe the apple or anything else as possessing certain properties involves us also having to say that there exists a possessor of these properties and this possessor is a substance, that which is permanent underneath all the changes of the modes. This distinction is important to Descartes because the fact that the accidents or modes change whilst the substance remains the same enables him to say that the former are less real than the latter, that their reality is less objective. This leads him back to the subject of God. Just as the notion of a substance is more objective than the notion of an accident so the idea of God has, he states, more objective reality in it than does the idea of an ordinary substance. All substances other than God are finite, that is, they are bounded in power whilst the substance of God is infinite or without boundary. Since God is infinite or without boundary whilst all other substances are bounded so the notion of God is more real than the notion of finite substances. But what contains less reality must be dependent upon that which possesses more reality so finite substances must depend upon God. Not only is this an

5 5/8 argument concerning the ideas of the things. That is, it is not just that my idea of a finite substance requires the idea of an infinite one. But if I have the idea of a finite substance and I concede that this idea contains more reality than the accidents said to belong to the substance then I have reason to think that this idea must have arisen in me from something which is at least equivalent to it in force. This is so because if the thought of the finite substance did not arise from finite substances then it must have arisen in any case from something capable of having the forcefulness and independence of me that this notion has as otherwise the idea would have come from nowhere. But since the idea is more real than the qualities said to belong to it then it cannot have come from nothing. Not only is it the case however that the idea of the substance is more real than that of the accidents said to belong to it but this idea is itself less real than the idea of God so if the idea of a finite substance does not come from existing finite substances then it must have come from something more real than it but what is more real than it is God. This is presented as a reason to think that God exists but this argument alone is unlikely to be sufficient to convince us as it really turns not just on the difference of reality between things but on a presumed identification of that which is infinite with God and we might, after all, doubt that these two notions do coincide. When I examine all the thoughts of things that I have, I am aware that the notions I have of all sensory things could have come from myself, that is, I could have imagined them. As with the wax, so with all sensory

6 6/8 things, the qualities they seemingly possess are all changeable and uncertain. Even the substances underlying the accidents of these things may not exist as the notion of this distinction between substance and accident could have arisen in me by extension from my own case. I know I exist and yet almost all my qualities undergo change so I distinguish between my substance and my accidents and perhaps this was how I arrived at this distinction with regard to appearances. Therefore nothing that appears external to me seems necessarily to be actually external to me. But this seems different with the idea of God. This is because the idea of God includes attributes that I do not possess such as being an infinite substance, being all-powerful and all knowing. Since these attributes do not match my own then the notion of them must belong to the notion in question as part of its nature and that leads to the conclusion that the object that the idea describes must of something that necessarily exists. A further reason for thinking that there must be a God is that otherwise it would appear that my existence was either dependent on myself alone or on some other finite substance. But if I was self-created then I would not be imperfect as I am but would be God. Further, what caused me to exist must possess as much reality as me and hence must be a thinking thing and capable of supplying me with ideas like that of God. But only God suffices as an explanation as otherwise finite beings would cause themselves and this contradicts their imperfection. The idea of God furthermore cannot

7 7/8 have arisen in me from the senses and I cannot have invented it because it is too perfect a concept for me to have invented it so it must be innate in me. The suggestion that the idea of God is something that is innate in me is based not just on a denial that we could have arrived at this notion from the senses. It is also that the conception of God is based upon our clear and distinct perception of a number of other ideas that necessarily lead us to formulate the conception of God. These other ideas include infinity, unity, simplicity, perfection, substance and immateriality but also the elements that are required to explain causation. Causation is here alleged to require a match between cause and effect and a basis for the persistence of causes. I may previously for example have taken the cause of my own existence to have been acts performed by my parents. However even if such acts brought me into being they required the parents themselves to be constantly sustained in being and, furthermore, I have to be sustained in being by something once I am here. The basis of the persistence of causal power is here suggested to require something beyond any given particular causal action as no particular action could preserve me in being. When we add this consideration to the combination of ideas that I find I need (such as substance, infinity and perfection) I am led to the conclusion that both the basis of the preservation and conservation of causal power and the ground of my own most distinct ideas must reside in the same thing, namely, God. Finally, the idea of God allows us to remove the objection to mathematical knowledge that we put forward in the First Meditation on the

8 8/8 basis that God could be a deceiver. That suggestion was based on an incomplete conception of God as it allowed both that God could be allpowerful and also a deceiver. Descartes now points out that there is no basis for deception in a perfect being as deception is always evidence of lack of power and perfection. Nothing that has sufficient power to bring about whatever ends it desires needs to deceive and nor, if perfect, would it wish to. Hence since he has proved the existence of God he has at the same time showed that there is no ground for us being deceived concerning mathematical knowledge which is sufficient to show that what it tells us about the nature of things must be true.

Philosophy 203 History of Modern Western Philosophy. Russell Marcus Hamilton College Spring 2010

Philosophy 203 History of Modern Western Philosophy Russell Marcus Hamilton College Spring 2010 Class 3 - Meditations Two and Three too much material, but we ll do what we can Marcus, Modern Philosophy,