The music in this podcast episode comes from the album Subliminal Mind Pub by Nick Herman. Purchase the full album on Bandcamp. Support indie artists!
Before getting into Descartes, I want to share some news with you. Philosopher
whose EM panpsychist theory of consciousness I introduced you to a while back has published a review of our book, Truth and Generosity. in The Journal of Mind and Behavior. (Click the image below to read it). I can’t thank Mostyn enough for all the work he has put into this, as I know getting a self-published book reviewed in an academic journal is nothing short of a miracle!
In my last post we discussed the first two Meditations from Descartes’ work, Meditations on First Philosophy, and here we’ll finish up. Here’s another site with audio readings of the Meditations. Feel free to follow along!
THIRD MEDITATION
At the beginning of the Third Meditation, Descartes reaffirms the measure of truth must be contained within himself: “I am certain that I am a thinking thing; but do I not therefore know what is required to render me certain of anything?” But even while saying “I am certain that I am a thinking thing,” Descartes again finds a way to doubt his previous discoveries:
“And certainly, since I have no reason to believe that there is some deceiving God, and since I haven’t yet considered the proofs for the existence of any God whatsoever, the ground of doubt that rests only on this supposition is very slight, and, so to speak, metaphysical. But in order to be able to completely remove it, I should inquire as to whether there is a God as soon as the opportunity presents itself; and, if I find that there is one, I should also find out if he can be a deceiver, for without the knowledge of these two truths, I don’t see how I can ever be certain of anything.”1
According to Descartes, the only way to discount the evil genius is by showing that God exists and could not be a deceiver—otherwise he can’t be certain of anything. Which means even clear and distinct ideas, i.e., the cogito and mathematical propositions, ultimately depend on the existence of a non-deceiving God.
He begins not with the famous ontological argument, but with this:
“Now it is manifest by the natural light that there must be at least as much reality in the efficient cause and total cause as in its effect; for from whence can the effect draw its reality if not from its cause?”
The cause of my idea of a perfect God must come from a real perfect God. Descartes explains why his skepticism towards sensible objects doesn’t apply to his idea of God:
“Although I have many thoughts of things outside of myself, like the sky, the earth, light, heat and a thousand others, I did not struggle at all to know where they came from, but because I saw nothing in them which would render them superior to me, I could believe that, if they were true, they were dependent on my nature…”2
I know I’m not perfect, yet I have an idea of a perfect being. This perfect being must exist and be the cause of my idea of it, because perfection cannot be born from imperfection. On the other hand, I can doubt that my ideas derived from sense perception derive from external reality because sensible objects are less perfect than me.3
FOUTH MEDITATION
Now that we know God is perfect and exists, we can also deduce that God would not deceive us, for deception is a sign of imperfection. Whoopie! Reality really is real!
Not so fast. Descartes has some explaining to: How can we ever be wrong if God is perfect and doesn’t deceive us? Descartes responds to this problem in two ways:
First of all, God can only assure us of our clear and distinct ideas. Any idea that is not clear and distinct is still prone to error.
Secondly, we make mistakes because we have the freedom to affirm or deny the truth. The will is in essence different from the understanding; it is unlimited, whereas the understanding is limited. I can be mistaken when I will or affirm something beyond the bounds of my understanding:
“Then where do my errors come from? They can only come from the will covering a much wider range than the understanding because I don’t contain it within the same limits, but I extend it even to things that I don’t understand. And as the will is itself indifferent, it easily chooses the bad instead of the good or the false instead of the true.”4
The will is the cause of error, but only when it goes beyond the understanding. Now we see the purpose behind his method of doubt. While doubting, the will places a check on itself, preventing itself from going beyond the understanding and preventing us from falling into error. But my will can no longer place a check on itself when I doubt clear and distinct ideas such as the cogito, for as we have seen, the cogito cannot be doubted without engendering contradiction.
There can be no way of falling into error once I know that God exists and is not a deceiver AND that my will has not affirmed anything beyond my understanding. Knowledge of God’s existence can only secure our knowledge of clear and distinct ideas.
FIFTH MEDITATION
The next argument for the existence of God is often referred to as the ontological argument. Its placement in the fifth Meditation seems strange since Descartes has already provided a proof for the existence of God; there seems to be no reason for a further proof. But there it is. Anyway, let’s be generous and just assume all his arguments for the existence of God are both valid and sound. According to Descartes, the idea of God implies the existence of God, by definition:
“For, being accustomed to distinguish between existence and essence in all other matters, I easily persuaded myself that existence can be separated from the essence of God, and that therefore one can conceive of God as not actually existing. But nevertheless, when I think of it more attentively, I clearly find that existence can no more be separated from the essence of God than the equality of three angles to two rights angles from the essence of a rectilinear triangle, or even the idea of a valley from the idea of a mountain; in such a way, there is no less repugnance in thinking of a God (or in other words, a perfect being) to which existence is lacking than to conceive of a mountain with no valley at all.”5
Absolute perfection necessitates existence; an absolutely perfect thing could not at the same time be a mere fiction of my mind and yet retain its perfection. God cannot be anything but absolute perfection, for God would not be God without at the same time being perfect (all-powerful, non-deceiving, etc). In other words, God’s essence entails existence. Therefore, God exists by definition, just as geometrical demonstrations contain within themselves their proofs.
SIXTH MEDITATION
Proof of the existence of a non-deceiving God was necessary to show that clear and distinct ideas are true, and to ensure that I can properly deduce other knowledge from these without being deceived. Now that Descartes has proven that a non-deceiving God exists (and, as I have said previously, I will not dispute these proofs), here in the last Meditation he tries to show how we can know external reality:
“The only thing left for me to examine is the existence of material things: Certainly at the very least I already know that they exist in so far as they are objects of geometrical demonstrations, seeing that in this way I conceive of them very clearly and very distinctly.”6
Material things are known “clearly and distinctly” by the intellect, through geometrical demonstrations. We can know reality, but only mathematically.
Returning to the wax example in the second Meditation, we see that Descartes had already assumed as much—that material things can be known clearly and distinctly only insofar as they are known mathematically—and only needed to verify that God is not a deceiver. The piece of wax could not be known by the properties that we would normally associate with it, such as hardness, color, smell, and other sensible qualities, but only by the idea of extension in general—extension as it is applied to all objects, or any object whatsoever. The proper way to know material objects is, according to Descartes, through mathematical concepts involved in the idea of extension in general.
Now we know in what way material objects are to be known, if they are to be known, but we have yet to see Descartes prove that they exist. He argues that because a perfect, non-deceiving God exists, it is highly unlikely we would be deceived in believing material objects exist as well:
“Because he [God] has not given me any faculty for knowing this is the case, but on the contrary, a very strong inclination to believe that they have been given to me or that they come from corporeal objects, I don’t see how we can excuse him of deception if, in fact, the ideas came from or were produced by causes other than corporeal things; therefore, we must admit that corporeal things exist.”7
So Descartes fails to prove that material objects exist, strictly speaking. He finds that, while he has not been given the “faculty for knowing this is the case,” he must believe that material objects exist. God would have to be a deceiver if material objects didn’t really exist, for God has given him a “strong inclination to believe” in corporeal objects; therefore “we must admit that corporeal things exist.” After a rigorous application of extreme doubt, Descartes seems to permit one belief—or rather, one God-given “strong inclination”.
But he doesn’t say material objects exist in just the way that we perceive them. External objects are known in so far as they can be understood mathematically as extension.
“However, perhaps they [external objects] are not entirely such as we perceive them by our senses, for sense perception is very obscure and confused in many cases; but at least it is necessary to admit that all the things which I conceive clearly and distinctly, or in other words, everything that is included as an object of speculative geometry, is, generally speaking, truly external to me.”8
God doesn’t guarantee anything derived from sense perception—only clear and distinct ideas and the existence of external objects in general.
ALL WE CAN KNOW FOR CERTAIN (according to Descartes):
God exists.
God is no deceiver.
Because of the above, our clear and distinct ideas are true. Clear and distinct ideas include:
the cogito
the mathematical, geometrical (extension)
God’s essence entails existence (let’s ignore the circularity of this argument)
The cogito doesn’t help us know reality, and neither do the proofs for the existence of God. Therefore, we can know reality only through mathematics.
NOW THAT WE HAVE A BASIC UNDERSTANDING of Descartes’ arguments, as well as what he concluded from them, we can see what has been excluded from the realm of certain knowledge—morality and aesthetics, for sure, but also all the qualities that make up the vast majority of our experiences.
In a previous post I criticized those who mischaracterize Cartesian introspection as being infallible. We’ve seen why that characterization leaves much to be desired, especially given that Descartes casts doubt on our ability to be certain of anything at all. Plus, by leveraging the will to explain how we can be wrong if God is not a deceiver, he makes it clear that we can be gravely mistaken about most things in life such as the qualities we experience through sensory perception, as well as ourselves. Only “clear and distinct” ideas pass the stress test; math is our only passage to reality.
What do YOU think?
Do you think Descartes is right about mathematical reality, that it’s more reliable than other ways of knowing? Does reliability make for a better kind of knowledge? Can everything be fruitfully mathematized? Art? Morality? Consciousness?
Hume once pointed out that even deductive reasoning relies on our memory—I can’t add numbers together if I can’t remember all the numbers. Hume’s skepticism would seem to cause trouble for Cartesian rationalism. Do you think Descartes can defend his ‘clear and distinct’ ideas from memory failure?
The music in this podcast episode comes from the album Subliminal Mind Pub by Nick Herman. Purchase the full album on Bandcamp. Support indie artists!
My translations. My French sucks, so if I messed up, please let me know!
« Et certes, puisque je n’ai aucune raison de croire qu’il y ait quelque Dieu qui soit trompeur, et même que je n’aie pas encore considéré celles qui prouvent qu’il y a un Dieu, la raison de douter qui dépend seulement de cette opinion est bien légère, et pour ainsi dire métaphysique. Mais afin de la pouvoir tout à fait ôter, je dois examiner s’il y a un Dieu, sitôt que l’occasion s’en présentera ; et si je trouve qu’il y en ait un, je dois aussi examiner s’il peut être trompeur : car sans la connaissance de ces deux vérités, je ne vois pas que je puisse jamais être certain d’aucune chose. » My italics. Ibid (see next footnote). Méditation Troisième [Meditation Three], AT IX, 28, pp. 97.
René Descartes, Œuvres et Lettres : Discours de la Méthode, Quatrième Partie [Works and Letters : Discourse on Method, Part Four], (Bruges, 1963: Sainte Catherine; reprint, 1953, Gallimard) pp. 149. All future references of this work are to this edition and all translations from the French are my own: « Pour ce qui est des pensées que j’avais de plusieurs autres choses hors de moi, comme du ciel, de la terre, de la lumière, de la chaleur et de mille autres, je n’était point tant en peine de savoir d’où elles venaient, à cause que, ne remarquant rien en elles qui me semblât les rendre supérieures à moi, je pouvais croire que, si elles étaient vraies, c’étaient des dépendances de ma nature… »
Eric Schwitzgebel and Alan T. Moore come up with a similar version of this argument against solipsism, one that doesn’t rely on the existence of God per se, in Experimental Evidence for the Existence of an External World.
« D’où est-ce donc que naissent mes erreurs? C’est à savoir de cela seul que, la volonté étant beaucoup plus ample et plus étendue que l’entendement, je ne la contiens pas dans les mêmes limites, mais que je l’étends aussi aux choses que je n’entends pas ; auxquelles étant de soi indifférente, elle s’égare fort aisément, et choisit le mal pour le bien, ou le faux pour le vrai. » Ibid. Méditation Quatrième [Meditation Four], AT IX, 46, pp. 145.
« Car, ayant accoutumé dans toutes les autres choses de faire distinction entre l’existence et l’essence, je me persuade aisément que l’existence peut être séparée de l’essence de Dieu, et qu’ainsi on peut concevoir Dieu comme n’étant pas actuellement. Mais néanmoins, lorsque j’y pense avec plus d’attention, je trouve manifestement que l’existence ne peut non plus être séparée de l’essence de Dieu, que de l’essence d’un triangle rectiligne la grandeur de ses trois angles égaux à deux droits, ou bien de l’idée d’une montagne l’idée d’une vallée ; en sorte qu’il n’y a pas moins de répugnance de concevoir un Dieu (c’est-à-dire un être souverainement parfait) auquel manque l’existence (c’est-à-dire auquel manque quelque perfection), que de concevoir une montagne qui n’ait point de vallée. » Ibid. Méditation Cinquième [Meditation Five], AT IX, 52, pp. 161.
« Il ne me reste plus maintenant qu'à examiner s’il y a des choses matérielles : et certes au moins sais-je déjà l’objet des démonstrations de géométrie, vu que de cette façon je les conçois fort clairement et fort distinctement. » Ibid. Méditation Sixième [Meditation Six], AT IX, 57, pp. 173.
« Car ne m’ayant donné aucune faculté pour connaître que cela soit, mais au contraire une très grande inclination à croire qu’elles me sont envoyées ou qu’elles partent des choses corporelles, je ne vois pas comment on pourrait l’excuser de tromperie, si en effet ces idées partaient ou étaient produites par d’autres causes que par des choses corporelles. Et partant il faut confesser qu’il y a des choses corporelles qui existent. » Ibid. Méditation Sixième [Meditation Six], AT IX, 63, pp. 189.
« Toutefois elles ne sont peut-être pas entièrement telles que nous les apercevons par le sens, car cette perception des sens est fort obscure et confuse en plusieurs choses ; mais au moins faut-il avouer que toutes les choses que j’y conçois clairement et distinctement, c’est-à-dire toutes les choses, généralement parlant, qui sont comprises dans l’objet de la géométrie spéculative, s’y retrouvent véritablement. » Ibid. Méditation Sixième [Meditation Six], AT IX, 63, pp. 189.
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