[lukev]

It is entirely uncontroversial that mental states affect the physical body. You've probably observed this yourself, directly, if you've ever had headaches or muscle tightness related to mental or emotional stress.

We can use MRIs to directly observe brain differences due to habitual mental activities (e.g. professional chess players, polyglots, musicians.)

It would be extremely odd if our bodies did not change as a result of mental activity. Your muscles grow differently if you exercise them, why would the nervous or hormonal systems be any different?

[epiccoleman]

I think my question is more a question of how whether than whether, if that makes sense. There is something about "thought" affecting "matter" that feels spooky if there is a bidirectional relationship.

If thought / consciousness / mind is purely downstream of physics, no spookiness. If somehow experienced states of mind can reach back and cause physical effects... that feels harder to explain. It feels like a sort of violation, somehow, of determinism.

Again though, as above, I'm basically a day into reading and thinking about this, so it might just be the case that I haven't understood the consensus yet and maybe it's not spooky at all. (I don't think this is the case though - just a quick skim through the Wikipedia page on "the hard problem of consciousness" seems to suggest a lot of closely related debate)

[bccdee]

You've struck at the essential problem of dualism. If thoughts are nonphysical, how can thoughts influence our physical bodies? If consciousness does not interact with the physical world, but merely arises from it, then how can we possibly discuss it, since anything we describe is causally linked to our description of it?

Descartes thought the soul was linked to the body through the pineal gland, inspiring a long tradition of mystic woo associated with what is, in fact, a fairly pedestrian endocrine gland.

Further reading, if you're interested:

https://plato.stanford.edu/entries/dualism/

https://plato.stanford.edu/entries/consciousness/

Personally, my take is that we can't really trust our own accounts of consciousness. Humans describe feeling that their senses form a cohesive sensorium that passes smoothly through time as a unique, distinct entity, but that feeling is just a property of how our brains process sensory information into thoughts. The way we're built strongly disposes us to think that "conscious experience" is a real distinct thing, even if it's not even clear what we mean by that, and even if the implications of its existence don't make sense. So the simple answer to the hard problem, IMO, is that consciousness doesn't exist (not even conceptually), and we just use the word "consciousness" to describe a particular set of feelings and intuitions that don't really tell us much about the underlying reality of the mind.

[epiccoleman]

Thank you for the links!

[lukev]

I mean it's funny you mention Descartes, because I find the argument that consciousness is the ONLY thing you can really know exists for sure to be pretty compelling. (Descartes then significantly loses the thread, hah.)

I agree with you that consciousness is much more fragmented and nonlinear than we perceive it to be, but "I exist" seems pretty tautological to me (for values of "I" that are completely unspecified.)

[bccdee]

Since "I think therefore I am" is meant to be a foundation for reasoning, it precedes any real definitions of "I," "thinking" and "being." So I think it's really more of a set of definitions than a conclusion.

We have a noun, "thought," which we define very broadly so as not to require any other definitions, and another noun, the self, which those thoughts are assumed to belong to. I think this is presumptive; working from first principles, why must a thought have a thinker? The self is a really meaty concept and Descartes just sneaks it in there unremarked-upon.

If you take that out, all you get is "thoughts exist." And even then, we're basically pointing at thoughts and saying "whatever these are doing is existing." Like, does a fictional character "exist" in the same way a real person does do? No, I think it's safe to say it's doing something different. But we point at whatever our thoughts are doing and define it as existence.

So I don't think we can learn much about the self or consciousness from Cartesian first-principles reasoning.

[epiccoleman]

I definitely share this intuition - it almost, in some sense, feels like the only thing we can really know. It makes it rather tough for me to accept the sibling comments arguing that "actually, the answer is that consciousness is an illusion." That just seems... transparently experientally false, to me.

[bccdee]

Here's my issue, though: Consider that our thoughts are encoded in physical matter. Something about the arrangement of the chemicals and charges in our brain holds our thoughts as real-world objects, just as ink and paper can hold a piece of writing.

Given a piece of paper with some information written on it, does the contents of the message tell you anything about the paper itself? The message may say "this paper was made in Argentina," or "this message was written by James," but you can't necessarily trust it. You can't even know that "James" is a real person.

So just because we feel conscious—just because strong feelings of consciousness, of "me-being-here"-ness, are written into the substrate of our brains—why should that tell us anything?

Whatever the sheet of paper says, it could just as easily say the exact opposite. What conclusions can we possibly draw based on its contents?

[epiccoleman]

> So just because we feel conscious—just because strong feelings of consciousness, of "me-being-here"-ness, are written into the substrate of our brains—why should that tell us anything?

It's a fact about the universe that it feels a certain way to have a certain "brain state" - just like it's a fact about the universe that certain arrangements of ink and cellulose molecules comprise a piece of paper with a message written on it.

That fits perfectly well into a fully materialistic view of the universe. Where it starts to feel spooky to me is the question of whether thoughts themselves could have some sort of causal effect on the brain. Could a person with a healthy brain be lying safely in bed and "think themselves" into something "unhealthy?" Could I have a "realization" that somehow destabilizes my mind? It seems at least plausible that this can and does happen.

Maybe the conscious experience is pure side-effect - not causal at all. But even if the ultimate "truth" of that series of events is "a series of chemical reactions occurred which caused a long term destabilization of that individual's conscious experience," it feels incomplete somehow to try to describe that event without reference to the experiential component of it.

Whether we posit spooky downward causation or stick to pure materialism, there still seems to be a series of experiential phenomena in our universe which our current scientific approach seems unable to touch. That's not to say that we never could understand consciousness in purely material terms or that we could never devise experiments that help us describe it - it just seems like a big gap in our understanding of nature to me.