Note on Skepticism

This page is part of my advice/opinion pages.

Although it feels somewhat pretentious to have a “philosophy” section of these pages, I think it’s potentially useful for anyone curious about some of my beliefs and opinions to understand where they’re coming from.

There’s a key piece of Descartes’ Meditations (https:// en.wikipedia.org/wiki/Meditations_on_First_Philosophy) which I continue to find very convincing (Hume expands on this along with other skeptical philosophers), and which leads me to consider myself a skeptic (in the “I don’t believe certain knowledge is possible” sense, not in the “In dogmatically anti-Christian” sense):

Descartes starts by questioning the very foundations of knowledge, adopting a kind of radical doubt. “Let’s assume everything we think we know could be wrong, and then try to find out what we can actually derive and be certain of via logic”. The only problem is: there isn’t much that can be derived without at least some assumptions. Descartes basically winds up with the famous “I think, therefore I am” statement, which means “even the most scrupulous doubter, in virtue of being a doubter is at least able to think”, and so some kind of ‘self’ that’s capable of ‘thinking’ is something we can safely conclude is true. It’s a very clever observation, but the rest of the Medetations basically concludes that beyond that thinking self’s existence, there’s nothing we can be sure of (unless like Descartes we agree to take some things on faith, like the existence of God, which is somewhere I diverge from his thinking). Descartes treats this as a reductio-ad-absurdum argument that God must exist, but others (like me) treat it as a solid argument that “true objective knowledge” is impossible. There’s a bunch of interesting stuff that flows from “objective knowledge is impossible”, and there are several branches of skeptical philosophy that propose different attempts to answer the question “what non-objective kinds of knowledge can we have?”

Many natural scientists who have not studied philosophy recoil from this conclusion (I certainly did at first) and many people refuse to accept it (although I haven’t ever seen anything close to a compelling counter-argument). “What about the laws of physics? The scientific method?” To briefly address this: if in fact the laws of physics are going to change in the future (maybe gravity is scheduled to turn off next Tuesday), no amount of empirical observations made before next Tuesday could ever discover that fact. If we were able to derive some kind of “the universe needs to be fair and can’t change the laws principle” then great, but there isn’t really any good way to do that. Most people just assume that physical laws exist and are timeless, which has been a good assumption so far in history, but that’s (however useful) an assumption, not any kind of logically certain conclusion. Incidentally, “pragmatism” is the name of the response to skepticism that says “well if we have to pick assumptions, let’s pick ones that have good explanatory power and/or ones that are useful”. I’m happy to follow along with pragmatic assumptions, but I still recognize that these are assumptions, not certainties.

To me, the most useful result of understanding the limits of knowledge is that it helps me be respectful of non-scientific knowledge systems. I’ve got a strong instinct from my upbringing to assume that empirical knowledge is superior to all other belief and knowledge systems, but skepticism shows that science is just as much a matter of faith as any other religion or belief system. This doesn’t mean that I have to give equal respect to all assertions about the world, and it’s fine and good for me to have preferences between belief systems (e.g., I reject homeopathy and think others should do the same). It does mean I need to be humble and do my homework before rejecting things, and that “it’s not scientific” isn’t alone a valid basis for rejecting a belief system. It does mean recognizing that in some contexts there are some belief systems which are better than science in terms of pragmatic utility and/or simple veracity.