me wonder about just how much divergence there is in contemporary
philosophers' intuitions about physicality. In the spirit of intuition
calibration, I am hereby surveying Brain-Hammer Heads on the following:
True or false? Necessarily, for all x, if x is cube (or approximately
cubic) then x is physical.
If I am in "The Matrix", and I perceive myself to be in a computer generated room with a computer generated cube, is this cube physical? I'd think that the cube only existed in my perceptions of it, a la Kant.
ReplyDeleteAlternatively, what if I just pick out an arbitrary cube shaped area of empty space that I can see and say that this area is my cube...is that physical?
What if I see a cube in my dreams? Is that cube physical?
I think I'd have to say no. Cubes aren't necessarily (if ever) physical.
In the Matrix and dream scenarios, I'd deny that there is anything that is a cube. For example, I wouldn't say that your experiences were cubed, even if they had cube as part of their content.
ReplyDeleteDavid Braddon-Mitchell ("Against Ontologically Emergent Consciousness") claims that there may be logically possible worlds where non-physical substances are arranged spatially or some other way so as to map onto the geometry of spheres. If there were such a world, then in some sense something could be a sphere without being physical (he talks about spheres, but the point applies to cubes).
Since I don't have intuitions, I'll say instead that this is not clearly incoherent. So I'll say false. But my ontological conscience is kind of weak.
Martin R
Hi Martin,
ReplyDeleteThat's the right sort of thing to say about dreams of cubes. There is no such kind of cube which is a dream cube. There are kinds of dreams that are cube dreams. (Compare: A drawing of a lion is not a kind of animal.)
Thanks for the Braddon-Mitchell reference. That's the sort of thing I was wondering about. Are there antiphysicalist positions sufficiently unhinged as to allow for non-physical space-filling stuffs? Strikes me as kinda bonkers, (I take anything cubical, including a cubical region of empty space, to be physical). But let a thousand flowers bloom, I guess.
If you were in the matrix or in a dream, but were not aware of the fact, what experiment could you perform that would reveal that the cube was not in fact a "real" cube?
ReplyDeleteIf space is a Kantian form of intuition, not something that exists independently of our perceptions, then a cube of empty space would not be physical. This is supported by The Matrix argument I think, where we interpret the computer generated inputs as having a spatial dimension, even though no such dimension physically exists.
Obviously what we know are our observations...everything else is inferred. If our observations indicate "cubeness", then that's all there is to it. If later you wake up and realize it was a dream, then you can change from "I saw a cube" to "I saw a cube in my dream".
If you add enough restrictions to your definition, of course you can thereby eventually claim that cubes are necessarily physical.
But you are implicitly saying "Mandik-restricted cubes are physical". Not cubes in the general sense. An empty win.
Hi Allen,
ReplyDeleteI guess I would say more works needs to be done to get the conclusion that some cubes are non-physical. The Matrix and dream scenarios do not support this, for from the fact that you are experiencing as if there is a cube, it does not follow that there is something which is cubed. If I dream that I am eating a 20 pound cheesecake, does it follow that there is something which weighs 20 pounds? What would that be? Your argument seems to rest on equating properties represented by experiences with properties of experiences.
MR
true. if i picked 8 equidistant points in empty space, there would still be a cube, no?
ReplyDeleteas long as there's a universe with spacial relations there will be a physical cube.
an existential quantifier always makes a handy rock to scissors, though.
Nice points, Martin. Additionally, even if dreamt cubes or Matrix-hallucinated cubes were kinds of cubes, it still wouldn't follow that they were nonphysical without further assumptions such as the assumptions that minds, dreams, or Matrices are nonphysical.
ReplyDeleteAs for drawings of lions and 20-lb cakes, those are oranges. We are discussing apples. What definition are you using for "lion"? 20-lbs...this implies gravity. Cheesecake involves and matter and perhaps a causal history that must include cows and chickens...so we'd have to get into definitions of these things as well.
ReplyDeleteThough, for that matter, you haven't really defined "physical" either.
A cube is defined purely in terms of spatial extent.
If what we refer to as "space" is something that only exists in our perceptions, then cubes only exist in our perceptions, and thus are not physical.
The Matrix thought experiment (as well as computationalism, e.g., brain simulations) would seem to imply that space is an aspect of our perception and processing of information, not necessarily something that exists external and independent of us. Again: Kant...our observations do not necessarily reveal anything about what really exists or how things really are. This fits very well with "simulation arguments" like the Matrix.
So, cubes are not necessarily physical.
Alternatively, one could point to "The Holographic Universe" hypothesis, where we experience the world as three dimensional, but what *really* (physically) exists are two dimensions. Cubes require 3 spatial dimensions by definition, therefore cubes could not be said to be physical. They would fall more under the category of illusion...and illusions are something in the mind of an observer.
As for "properties represented by experiences" vs. "properties of experiences", all that we know are our experiences. Everything else is inferred. You are making the assumption that there are properties that exist independently of our experience...but you have more work to do to get to that conclusion!
and what if we designated 8 temporal points?
ReplyDeletei can't get my google account to work even though i've been using 'chrome'.
If we designated 8 temporal points you would have to show that time is not one dimensional otherwise you just have a line but nothing cubic.
ReplyDeleteAllen,
ReplyDeleteEven if we take the Kantian route being proposed, it's still not clear you get non-physical cubes. Kant says space is an a priori form of intuition (and geometry describes the properties of this space), but he thought objects had shapes, not our ideas of objects (he wasn't Berkeley). So from the fact that our mind "contributes" something to objects, it does not follow that what the mind contributes has the very properties contributed. Kant would not say that minds were cubed, or that ideas were cubed. Cardboard boxes and pieces of cheese, etc., are cubed, and those are physical objects (even for Kant!). I think this is also suggested when Kant remarks that a succession of perceptions is not the perception of succession. Kant is warning us not to confuse properties represented with properties of representations.
But I'm no Kant scholar (I just play one on the internets), so maybe this is an amateurish reading of Kant.
MR
So I am also no Kant scholar, BUT, let me quote one (or at least someone who plays one on the internet!):
ReplyDelete"Having seen Kant's transcendental deduction of the categories as pure concepts of the understanding applicable a priori to every possible experience, we might naturally wish to ask the further question whether these regulative principles are really true. Are there substances? Does every event have a cause? Do all things interact? Given that we must suppose them in order to have any experience, do they obtain in the world itself? To these further questions, Kant firmly refused to offer any answer.
According to Kant, it is vital always to distinguish between the distinct realms of phenomena and noumena. Phenomena are the appearances, which constitute the our experience; noumena are the (presumed) things themselves, which constitute reality. All of our synthetic a priori judgments apply only to the phenomenal realm, not the noumenal. (It is only at this level, with respect to what we can experience, that we are justified in imposing the structure of our concepts onto the objects of our knowledge.) Since the thing in itself (Ding an sich) would by definition be entirely independent of our experience of it, we are utterly ignorant of the noumenal realm.
Thus, on Kant's view, the most fundamental laws of nature, like the truths of mathematics, are knowable precisely because they make no effort to describe the world as it really is but rather prescribe the structure of the world as we experience it. By applying the pure forms of sensible intuition and the pure concepts of the understanding, we achieve a systematic view of the phenomenal realm but learn nothing of the noumenal realm. Math and science are certainly true of the phenomena; only metaphysics claims to instruct us about the noumena."
Okay, with that in mind, let me try to clarify my previous point:
A cube is defined purely in terms of spatial extent.
If what we refer to as "space" is something that only exists in our perceptions, then cubes only exist in our perceptions, and thus are not physical...EVEN IF our perceptions of the cube were CAUSED by something physical.
So the computer simulation that runs The Matrix has some electrons in a particular configuration that represents a cube. The information represented by these electrons is fed into our nervous system, and cause us to perceive an object that meets the definition of a cube. The electrons caused our perception of the cube, but did not themselves meet the definition of a cube.
In the Holographic Universe example it would be the same. The 2-D physics of the holographic universe act on us in such a way as to cause us to perceive a 3D cube. But nothing in the 2D universe meets the definition of a cube.
So a physicalist I assume would argue that perceptions are physical, because everything is physical. In which case there's no point in even asking the question in the original post. You've already arranged your definitions so that the answer is a foregone conclusion. But since your definition is based on assumptions, I'd say it's another empty win. Different assumptions give a different conclusion.