I recently had an extraordinarily stimulating conversation with two friends who wish to remain anonymous (but they know who they are). The topic: can we ever have certain knowledge about anything? My initial response, not intended to be flippant, was: I’m not certain.
The friends claimed certainty about things that I don’t think we can reasonably be certain about. One claimed to have achieved certain knowledge through the Sufi practice of dhikr; I argued that this could be a feeling of certainty about falsehood rather than about truth, so that one needs standards of truth external to the mystical experience. The other claimed that we could know with certainty that we are awake and not sleeping; I wasn’t ready to grant that. I’m ready to grant the basic point of Descartes’s skepticism: although we can be relatively confident that the things of the world are as they seem, it’s possible they could all be a dream, or the creation of an evil demon – or even the Matrix. (What a gift that movie is to teachers of introductory philosophy!)
Now Descartes himself thinks he can have certain knowledge in spite of all this doubt, or in a certain sense even because of it: he believes that the one thing he can’t doubt is the fact that he is doubting. His doubt would be logically self-contradictory, for its very existence would require the presence of a doubter, namely himself. Thus, “I think therefore I am” (cogito ergo sum).
My Buddhist readers will probably be unsympathetic to Descartes’s argument, and rightly so. Descartes tries here to prove the very thing that the Buddha of the Pali suttas – and the vast majority of later Buddhists – would be at pains to deny, namely the existence of the self. I would argue that a Buddhist critique knocks Descartes down quite effectively. Descartes may have established the existence of doubt, but not of an agent of doubt, of a doubter. That’s an error, a reification. As a popular book on Buddhism has it, there are thoughts without a thinker. Even if one disagrees with Buddhist deconstructions of the self – and I am often skeptical of them – one must surely still acknowledge that they at least cast doubt on the self, the thing Descartes thought could not be doubted.
Nevertheless, there’s a route to certain knowledge that one can still follow from here. The basic Buddhist critique knocks down certainty about the thinking self; it does not knock down the more basic pursuit of foundations and certainty in the face of skepticism. Descartes had a basically sound insight in one respect: while you might doubt the existence of a doubter, you cannot doubt the existence of doubt itself! If Descartes was really aiming for a completely certain foundation to stand on, he would have been better off saying: “There is thinking, therefore there is being.”
It’s there, in thought itself, where I would look for certain knowledge. Thought must be possible; the existence of the idea that thought isn’t possible implies that it is. Even in the Matrix, thought must be possible; it cannot be otherwise. Moreover, the existence of thought seems to require something like Aristotle’s laws of logic; without them, thought cannot make sense. Everything is what it is (the law of identity); and nothing can both be and not be in the same time and in the same respect (the law of non-contradiction). Less sure about his third law, the law of the excluded middle (everything either is or is not); that one’s been quite plausibly challenged by contemporary intuitionistic logic, and before that by Madhyamaka Buddhists like Nāgārjuna. But a denial of identity or non-contradiction effectively invalidates itself.
Here, in the realms of thought and logic, is where I would look for certainty. (Plato’s venture into mathematics is also a plausible place to look: even in the Matrix, one would think, 2+2 is always 4.) The possibility of thought, the law of identity: these things seem incontrovertible. But that’s just the problem: maybe they only seem incontrovertible. Descartes thought that the existence of the self was an ironclad, logically irrefutable foundation; but he turns out to be wrong. As far as I can tell, the existence of thought or the law of non-contradiction are irrefutable. But couldn’t I be missing something the way Descartes was?