refutation of anonymous person's philosophy of mind

a friend of mine recently co-authored a journal review of the film inception. i haven't personally seen the film, but the article gives away enough of the plot to give context for its review and suggest possible philosophical implications from the film's content. here is the part of the article concerning what i want to address:


The hierarchical structure of dreams within dreams raises the profound philosophical question: how do you know when you’re dreaming and when you’re awake? For the film’s target, and even occasionally for team members (and also the audience), it is hard to tell the difference between dream and reality. After all, the target has to be convinced he is in a dream (which is itself within another dream). Furthermore, the film contains some ambiguity regarding what, if any level, was reality. The top level of the dream-within-dream hierarchy is presented to the viewer as reality, but, similar to the classic film Dreamscape (dir. Joseph Ruben, 1984), there is reason to suspect that even this top level is a dream. The film remains ambiguous on this matter, and appropriately so, as this ambiguity highlights the ambiguity we must face within our own lives about what actually is real.

The ambiguity about whether our perceived realities are indeed real is a topic of ongoing debate within the philosophy literatures on epistemology and philosophy of mind. A classic thought experiment in this realm is the brain in a vat (Brueckner 2006; Putnam 1981). Here we imagine a human brain placed in a vat of liquids containing all the nutrients necessary for the brain to survive and function. The vat also contains connections for sensory input to and information extraction from the brain. The connections are run through a computer which processes the brain’s thoughts and returns sensory input corresponding to a highly plausible perception of reality – so plausible that it would be indistinguishable from the reality we perceive. The question here is, how do we know we are not brains in vats? A similar thought experiment is the simulation argument (Bostrom 2003). Here, a powerful computer simulation contains simulated minds with all the complexity of our own. In parallel with the brain-in-vat thought experiment, the question here is, how do we not know we are a simulation within a computer program? The simple answer is that we don’t know, and cannot know. While this idea is more fully explored in the movie The Matrix (dir. Larry and Andy Wachowski, 1999), Inception raises the idea that if dreams can be that powerful – and that manipulable – then we may not be able to know whether or not we are in one.


an anonymous person thought that the above 2 paragraphs were basically bs, and responded with his own approach to philosophy of mind. his argument goes as follows:

what is reality?
reality is a perception
what is a dream?
dreams are a perception
done!


now, of course this seems like an oversimplification, and intuitively, it doesn't seem to make sense, but just what exactly is wrong with his argument? i broke it down and found the following faults:


1) he's assuming reality is solely epistemic instead of metaphysical or having a metaphysical component


2) here are my definitions of the two, which i believe to both be correct:

reality is: external physical objects --> perception --> conscious cognition (mostly conscious, but some unconscious too) --> one's experience

dreams are: internal representations formed from conscious and unconscious perception of external physical objects --> unconscious cognition --> one's experience

so, as you can see, by definition, reality and dreams are not equivalent or interchangeable. furthermore, dreams are dependent on reality in order to exist, so technically, you can add the first three steps of "reality" before the first step of "dreams".


3) reality is assumed to be reality (as opposed to being assumed to be a simulation), but dreams are assumed to be a self-created simulation of sorts. since the two appear to be different, the question one must ask is what if reality is a simulation? how would it compare to our dreams? would it be exactly like a dream or would it be somewhat similar but also have differences? a simulated reality would be:

internal simulation --> internal representations formed from the simulation (how they are classified as perception or cognition depends on how one defines the phenomenology of the simulation, but in either case they serve as the "building blocks" from which the ultimate cognition is formed) --> conscious cognition (mostly, but some unconscious too) --> one's experience.

compare that to the dreams definition in #2 and you can see how the two can serve as loose analogies, but they are not one and the same. if one does away with the unconscious/conscious distinction and ignores the perception part, then the only difference is the formation of the initial premise (one which assumes an "external reality" and the other which assumes a simulation, thus accounting for an extra step, although remember that technically for dreams that occur in an "external reality" you can add the first three steps of reality before the first step in dreams). to clarify things and update them, here are the four definitions:

reality: external physical objects --> perception --> cognition --> experience

dreams: internal representations formed from an external reality --> cognition --> experience

simulated reality: simulation --> internal representations (whether they should be classified as perceptions or lower-level cognition remains open to debate) --> cognition --> experience

dreams within a simulated reality: internal representations (lower-level cognition) --> cognition --> experience

technically, since for dreams within a simulated reality internal representations are derived from the simulation, then you can include simulation as a step before internal representations. contrary to the anonymous person's belief that reality and dreams are the same due to perception, the exact opposite is true: the definition of perception is the only thing (in addition to the conscious/unconscious distinction) that separates simulated reality from dreams within a simulated reality. if we cannot differentiate between conscious and unconscious cognition, then it would be impossible to differentiate between perception and cognition, thus making dreams and a simulated reality equivalent.


4) even if reality is solely epistemic, as in some form of idealism, his comparison between the two would be different because for a revision of #2,

reality would be: idealism that projects as a substitute for an external reality --> perception --> cognition (mostly conscious, but some unconscious too) --> one's experience

dreams would be altered too: internal representations formed from conscious perception of idealism --> unconscious cognition --> one's experience

so the differences regardless of whether reality is solely epistemic or not are that dreams are unconscious whereas reality is conscious (mostly) and that reality involves some form of perception whereas dreams do not.


5) his own argument isn't internally sensible. if he had said reality = perception, and dreams = perception, therefore, reality = perception, then at least his argument would make sense if its premises were true (his premises are not true as 1-4 have proven). by saying "a perception", he leaves a lot open to interpretation as he does not denote what perception exactly he is referring to. for example, if reality is perception (subscript 1) and dreams are perception (subscript 2) -- a scenario perfectly plausible given how he wrote his argument -- then reality is not equivalent to dreams.


6) his definitions don't make sense. experience amounts to the holistic endpoint of perception + cognition, so he's missing half of the puzzle. also, he's confusing perception and cognition. if he wants to believe in idealism (reality is epistemic), and thus reality is only perception, then he can do that (although he's wrong in ignoring cognition), but in that case, dreams are not perception, they are cognition, albeit unconscious and being connected to perception on some level if a reality is assumed to exist (perception is required in order for representations to form in a person's mind which a person's cognition then uses unconsciously in forming dreams, so ultimately, in a vulgarly oversimplified form, dreams = cognition). contrasting the two, reality is perception and dreams are unconscious cognition. so not only are they not equivalent, but his model does not take into account the existence of conscious cognition, so his schema entailing reality and dreams is incomplete.