Yesterday on Twitter I posted:

Has anyone applied Einstein’s theory of relativity to radical skepticism? i.e. spaces of reference in knowledge relative to each other.

Twitter is great for tossing out a quick idea, but on reflection, this one probably needs more explanation. To give credit where credit is due, the idea occurred to me while I was watching a Coursera lecture on Epistemology by Duncan Pritchard (University of Edinburgh) for an evening’s entertainment (what can I say, it’s more fun than most things on television). Though, ultimately, the idea is a distillation of several lines of thought that have been knocking around in my head for years now. (If you really, really want to get at the roots, it all goes back to Richard Jozsa, who was my professor in Quantum Computation at the University of Bristol before he moved on to Cambridge, and who set me on a whole new path of thinking.)

First, a bit of lightweight background, so everyone can follow along. In very rough terms, radical skepticism is a perspective on the fundamental nature of human knowledge, specifically that knowledge is impossible. Pritchard used the classic “brain in a vat” or “Matrix” illustration, which might be simply stated: If I were a brain in a vat, being fed fake experiences by a computer (far more advanced than any we currently have, but still, play along for the sake of argument), then everything I think I know about the universe would actually be fake. I wouldn’t really “know” anything. And the kicker is, there really isn’t any way to prove I’m not a brain in a vat, and therefore, at a very basic level there isn’t any way to prove that anything I know is true. (Apologies to academic philosophers who might happen to read this, I’m keeping the explanation as simple as possible.)

Now, relativity in physics (again, very much simplified) is a theory that examines motion within frames of reference. For an intuitive sense of what this means, go outside and throw a ball to a friend so they can catch it. Now, go ride on a train with the friend and throw a ball there (try not to hit the other passengers). The two situations have radically different external contexts, one is stationary on the sidewalk, the other is hurtling along the tracks. And yet, for you, the friend, and the ball, the motion is the same: if you throw the same way and catch the same way, the arc of the ball relative to the two of you would be the same. The train car forms a frame of reference, and you can meaningfully examine the laws of physics within that frame, while completely ignoring the motion outside the frame. And, of course, remember that even the “stationary” case is actually on a planet that’s spinning and hurtling through space around the sun, in a universe that’s also in constant motion.

(Digression: Years ago, I set out on a lark to memorise the entirety of an English translation of Einstein’s “Spezielle Relativitätstheorie” i.e. “The Theory of Special Relativity” (Doc. 71, Princeton Lectures). I still can’t recite the whole thing verbatim, but a funny thing happened along the way (as I took classes in quantum mechanics and astrophysics): at one point a lightbulb went off and I suddenly realized I wasn’t just memorizing anymore, I was beginning to understand what Einstein was talking about on a deep level.)

Okay, bringing it back around, the problem with radical skepticism is that if you declare that it’s impossible to know anything, then any study of the fundamental nature of human knowledge, philosophy, or ultimately our entire existence, is really rather meaningless. Simply saying “it doesn’t really matter if I’m a brain in a vat” is a shatteringly weak argument in the face of “everything you think you know is wrong”. And yet, the recorded history of humanity demonstrates that it’s possible to construct internally consistent systems of knowledge, and value in exploring the nature of that knowledge. What if, instead of trying to wave away radical skepticism in a puff of smoke, we instead accepted it as a fundamental truth, at the same time as systematizing a study of knowledge within frames of reference, analogous to Cartesian frames of geometry or relativity frames of motion. So, whether I am a brain in a vat, or a living, breathing physical organism experiencing a physical environment, I exist within a “frame of reference” (a computer-constructed or physical world). Within that frame it’s meaningful to study the system of knowledge, while abstracting away from details outside the frame. It’s even meaningful to study the nature of knowledge across different frames of reference, for example as either a brain in a vat or a physical organism I might “know” that I have two hands, that one of them is grasping a cup of coffee, etc, etc. In either frame, I have a true belief, reached through the reasonable application of my cognitive abilities. My knowledge of my hand and my knowledge of the coffee cup are the same relative to each other, within both frames of reference. In a sense, we can say that the “laws of knowledge” are consistent across frames of reference.

Let’s take it one step further. When I inhabit a virtual world, whether it’s as vast and mutable as Minecraft, or as carefully controlled as a game in the Zelda series, I enter into a frame of reference of knowledge. I become a “brain in a vat” to that virtual world, because my dual existence as a physical organism in a physical world isn’t relevant within that frame. This is only becoming more true as technologies like Emotiv’s EPOC controller begin to make the brain-to-world connection more direct, and technologies like Oculus Rift begin to make the world-to-brain connection more direct. Within the frame of reference of a virtual world, I may have genuine knowledge that I have two hands, and that one of them is holding an object. As a slightly more abstract but still narrow example, I may have knowledge of completely different physical laws in two frames of reference (one may not have gravity, or may permit me to fall from 1,000 feet without injury), and yet both have an internally consistent set of physical laws, and my knowledge of those physical laws is absolutely essential to my ability to function as an entity within that frame of reference. And, I can meaningfully compare the nature of my knowledge of physical laws across the two frames of reference, even though the physical laws themselves are different. So frames of reference in knowledge aren’t merely an academic abstraction for the sake of reconciling two apparently conflicting approaches to philosophy. They’re also potentially a valuable tool in the study of the fundamental nature of human knowledge, in much the same way that relativity was to physics.

BTW, if anyone knows of research or published articles heading in this general direction of thought, I’d be very interested to hear/read more about it.