This is a list of philosophical questions I’m currently grappling with.

Truth and objectivity

I tend to be a realist, i.e. I think there are objective truths about the world, whether or not we’re aware of those truths. And for a while I’ve had the view that through science, philosophy, conjecture, reason, and error-correction, we could get closer to knowing those objective truths. (Some thoughts on objectivity here.)

Recently I’ve been less sure about (1) the existence of such definite, objective facts describing the world, and (2) whether error-correction actually helps us get closer to those facts.

  • My doubts about #1 come from Jake Orthwein’s Do Explain episode where he discusses David Chapman’s work. Chapman claims that reality itself has some nebulosity to it: there is no set of definite propositions describing the world in its entirety. I’m curious to explore his work further.
  • My doubts about #2 come from David Deutsch’s assertion in this video that as critical rationalists, we’re not actually striving for the truth – we’re just trying to correct errors. (Are these the same thing? It seems they may not be.)

This article about truthlikeness also got me wondering about whether the notion of proximity towards truth is misguided.

Reductionism and levels of explanation

The first chapter of The Fabric of Reality convinced me that reductionism is an error: the best explanation of something does not always result from breaking it down into its tiniest parts.

Deutsch says that multiple different levels of explanation can coexist – we can understand a lot about a cup of water without thinking of it as the amalgamation of trillions of atoms.

There is no reason to regard high-level theories as in any way ‘second-class citizens’. Our theories of subatomic physics, and even of quantum theory or relativity, are in no way privileged relative to theories about emergent properties. None of these areas of knowledge can possibly subsume all the others. Each of them has logical implications for the others, but not all the implications can be stated, for they are emergent properties of the other theories’ domains.

I think Deutsch makes a compelling argument that reductionism is nothing more than a mistake born of our intuitions, but part of me is having difficulty letting go of it. I guess the question I have is: if low-level theories do not subsume high-level theories, how exactly do the low and high levels relate to each other?

To put it concretely: I can describe the same thing at different levels of explanation, e.g. ‘cup of water’ vs ‘collection of trillions of H₂O molecules’. A reductionist would say the ‘cup of water’ description is made up, is less true, is just an illusory approximation of the truer and more precise ‘molecules’ description. In contrast, Deutsch would say no, they are both valid descriptions, relevant to different problems.

But what Deutsch doesn’t address is what the relationship between the two levels is, why they both exist in the first place, why ’trillions of molecules’ corresponds to ‘cup of water’ and not to something else. Why and how does emergence happen?

Hard problem of consciousness

I keep going back and forth on whether I think there is a hard problem of consciousness, and whether consciousness is fundamental to reality or not.

Bernardo Kastrup makes a compelling argument here that consciousness must play a fundamental role in our metaphysics, and that physicalism is deeply flawed. Other scientists like Donald Hoffman are working on theories of reality that take consciousness as a primitive.

Conversely, some scientists and philosophers think consciousness is merely an emergent property of information processing, and that the base layer of reality is non-conscious matter and energy. (Per the previous section, the very concept of a ‘base layer of reality’ entails assumptions about levels of explanation.)

Deutsch and other critical rationalists seem to argue that the hard problem of consciousness is nothing more than a reductionist error, and that we may be able to explain consciousness purely in terms of abstract entities. But even if we did that, I still see an explanatory gap between abstract entities and qualia; why would a given abstraction (e.g. a particular graph structure) correspond to a particular conscious experience like the color blue?

At this point, I don’t see how any explanation of unconscious physical processes—or of abstract entities—could ever possibly give us a description or prediction of qualia. So yes, I do think there is a hard problem and this does lead me towards the view that consciousness is somehow fundamental.