Erik Hammar

I am lucky to have a girlfriend who understands my academic passions. I recently received a cherished gift from her, a beautiful little edition of Rene Descartes’ brief but worthwhile Discourse on the Method (various title translations; 1637). It is an autobiographical and philosophical work, in which Descartes tracks his record in developing and living according to a certain “method for the well guiding of reason” he has devised. The four maxims which constitutes this method are quite interesting, so let me quote them almost in full:

1. “The first was, never to receive any thing for true, but what I evidently knew to be so”
2. “The second, to divide every one of these difficulties, which I was to examine into as many parcels as could be, and, as was requisite the better to resolve them”
3. “The third, to lead my thoughts in order, beginning by the simple objects, and the easiest to be known; to rise little by little, as by steps, even to the knowledge of te most mised, and even supposing and order among those which naturally do not precede one the other”
4. “And the last, to make everywhere such exact calculations, and such general reviews, that I might be confident to have omitted nothing”

A set of criteria for the method of gaining knowledge, he says, inspired by the step-by-step deductions of the geometricians and mathematicians. These maxims indicate what I think is interesting, that the common portrayal as Descartes as a skeptic and pessimist about knowledge is inaccurate and confused. Descartes thinks, quite simply, that there is quite a lot of things that human beings have the ability to gain firm knowledge about, although he is very aware of the risks of personal and cultural bias and prejudice we always run in doing so. In light of this, I want to elaborate and put into context Descartes’ thought, but I must apologise in advance to those who are experts on Descartes specifically, as opposed to philosophically interested generally – I am no expert on Descartes. My summaries and interpretations will be crude. (I also don’t aim to criticise Descartes’ views, as I am afraid I don’t have time to write that much.) However, what is partly crude need not be fully useless, if it can offer introduction or useful overview.

To remind, Descartes is most famous for his “method of doubt”, expounded most elaborately in his Meditations on First Philosophy, whereby he starts by clearing away all those bits of knowledge that he can conceivably doubt, to see what remains. Sensory impressions, for example, must initially go, since they can be doubted on the basis that we can believe that we have certain sensory experiences when we are dreaming or delirious. What is left, he asks, if I remove from the tables of my mind all that I can conceivably doubt. Famously, he argues that the one thing about the world that he cannot doubt is that he himself exists, since in doubting, he is thinking, and thus, there is something that thinks (cogito, ergo sum).

However, because the summary of Descartes often stops at this point, he has become something (I believe) of the embodiment of the caricature philosopher – the lofty, detached skeptic, questioning how you know you are sitting in a chair and that you are eating müesli, as everyone else gets on with the business of real life. Now, as an aside, even if this were a true characterisation of Descartes’ views, the disregard for it would be up for grabs. Skepticism about your eating müesli might be a defensible epistemological position in some sense, and nothing immediately follows about whether you should disheartedly drop your spoon or defiantly keep crunching your müesli in the face of its ontological dubiousness.

But to return to Descartes, the crucial distinction is that between doubt as philosophical method and doubt as philosophical position. The latter, only, is skepticism. Descartes tries to demolish the apparent foundations of knowledge through the method of doubt, only in the hope to erect a more stable epistemological abode on top of them. Put in its context his attempt is put in a very different light from that of the Philosophy 101 caricature. Descartes is writing in the midst of the intellectual upheaval of the Enlightenment and the ideological debates between established Church and Science. He is looking for a foundation for science, rather than a bizarre skeptical argument for doubting the material world of chairs and tables around us.

His argument, shorltly, is something like what follows. He can perceive, in his famous phrase, “clearly and distinctly”, that it could not be the case that he did not exist yet was thinking. Since he is thinking (specifically, doubting), then in exactly the same way as he can infer that it is true that 2+2=4 from the inconceivability of its not being so, he can infer that he actually does exist from the fact that he is thinking (doubting).

Introspecting into the self the existence of which he has thus established on firm grounds, he discovers that he has in himself certain ideas. These ideas include mountains, animals, etc. But they also include a subset of other notions of perfection, of which the key one is the composite idea of a being more perfect than himself in every conceivable way. He can see, he says in the Discourse on Method, that he is not perfect, since he has in him “the idea of a being more perfect than mine”. This idea, which it is “manifestly impossible” to regard “as nothing”, cannot come from something less perfect than him (perfect, I understand it, in terms of reason). Having thus argued that he exists, has within him the idea of a more perfect being, and that this idea is clearly not nothing, he goes in for the great conclusion:

And because there is no less repugnancy that the more perfect should succeeed from and depend upon the less perfect, than for something to proceed from nothing, I could no more hold it from myself: So as it followed , that it must have been put into me by a nature which was truly more perfect than I, and even which had in it all the perfections whereof I could have an idea; to wit, (to explain myself in one word) God.

Descartes is often said to make use of the ontological argument for God’s existence (originally presented, I believe, by St. Anselm). I found it interesting that actually reading Descartes’ version, it does not really follow the standard summary of the ontological argument, which is: “We can imagine a perfect being. A perfect being would not be perfect if it lacked existence. Hence, a perfect being exists (and we call this being ‘God’).” (A wonderfully cunning argument. I believe that the standard view among philosophers is that it was Kant who finally demolished it by showing that existence is not a predicate in the standard way.) Now, Descartes argument says, instead, that he has the idea of perfection within him, and it could only have originated from something which is perfect. The argument here hinges on the premise that the idea of something perfect necessarily originates from a something perfect in the relevant way, or invertly, that the idea of something perfect cannot originate from something which is not perfect in that way . Hence, since the idea of perfection exists in us, the perfect being from which it must originate, exists (or theoretically, has existed). Importantly, the conclusion that God exists and has the qualitites of perfection is one which Descartes sees on par with mathematical proofs. It is one which no rational being who properly understands the argument can, in good faith, doubt. Thus he says:

As for example, I well perceive, that supposing a triangle, three angles necessarily must be equal to two right ones: but yet nevertheless I saw nothing which assured me that there was a triangle in the world. Whereas returning to examine the idea which I had of a perfect being, I found its existence comprised in it, in the same manner as it was comprised in that of a triangle, where the three angles are equal to two right ones; or in that of a sphere, where all the parts are equally distant from the centre. Or even yet more evidently, and that by consequence, it is at least as certain that God, who is that perfect being, is, or exists, as any demonstration in geometry can be.

Let us get back to the thread of the main story. How does this help Descartes in restoring proper foundations for knowledge, and in particular, scientific knowledge? Well, he goes on to leverage the conclusion that God exists to put back on the table of knowledge all those articles which his method of doubt has temporarily, as part of the skeptical exercise, displaced. If God is perfect in every way imaginable, he is also perfectly good, and so would not deceive the senses so, that the world around us is all the results of the machinations of an evil demon, that what we take to be real is not in any way so. A perfectly good God would not deceive us. Hence, we have reason to trust what careful examination and experimentation can indicate to us about the physical world.

It is indeed amazing how the commonly derided skeptic dreamer Descartes can thus very practically argue:

For they [the notions touching natural philosophy] made it appear to me, that it was possible to attain points of knowledge, which may be very profitable for this life: and that instead of this speculative philosophy which is taught in the Schools, we might find out a practical one /…/ as we know the several trades of our handicrafts, we might in the same manner employ them to all uses to which they are fit, and so become masters and possessors of nature.

For the sake of, he continues, convenience and good health – a most practical view indeed, or at least in comparison with the caricature of Descartes the skeptic. He concludes that he will spend his time studying medicine, as it is the most important science. “I think, therefore, we have solid epistemological foundations for the kind of scientific knowledge which we should use to bring convenience and good health to the public.” Perhaps less catchy, but, if I am not mistaken, a tad more complete a summary.