Derrick,

As you asked for comments, here are mine, for what they're worth.

1. The argument is logically deficient

Even if I grant, for the sake of argument, that there is some delay between the flash and the observer's perception of it, there seems to be a problem with your item 3. There, you say that it follows from the fact that there is a delay that "...what actually occurs between T + 100 milliseconds and T + 101 milliseconds in your vision must be merely a subsequent mental representation of the scene".

This claim really makes your further points trivial; if I buy item 3, then I've bought them all. Specifically, item 5 is merely an obvious generalization of the section of item 3 that I quoted above. The question then is: what argument do you present for your claim in item 3? I can find none, except the mere fact that there is a delay between the event and its perception. But this itself proves nothing; item 3 looks like a petitio to me.

Perhaps the proposition "if there is a delay between the event and my perception of it, then what I perceive can't be the real thing, but must be a mental representation of it" seems so obvious to you that you think no argument must really be presented for it. But if you do think this, then why pretend to present an argument at all?

By the way, Nigel Thomas raised a similar objection against the original form of your argument.

2. If we were subject to the "illusion" that we perceive the world, then your argument could not be stated.

If we have only the experience of the flash, and if this falls out to mean we cannot see the flash itself, then we can't know anything about the flash. In other words, your graphics should consist of only one row--the first. How could we determine when--or even if-- the "real" flash occurred, if we cannot--by virtue of your argument--know anything about it? The sequence of illustrations implies that we can fix both the flash and the observer's seeing of the flash in time, and measure the difference. I cannot imagine any scientific experiment that would establish such a temporal relationship.

You yourself raise what I take to be a version of this same argument in item 2) of your (full) paper: you attempt to demolish the assertion that representationalism is inherently unprovable. However, you do not seem to present a very forceful argument. You say of representationalism

"...such theories merely assume, rather than assert, that there exists a physical world and that the experiences that we call perceptions are indeed, somehow, experiences of that world."..."Therefore, contrary to this objection, the representative theory of perception merely asserts that if, as we assume, there exists a physical world and the experiences that we call perceptions are indeed experiences of that world, then what we directly experience perceptually isn't the physical world itself but merely a mental representation of it."

You seem to be opposing the objection to representationalism by saying that, according to representationalism, the existence of the "external" world is merely assumed. But that is precisely the objection! Far from refuting the claim of non-provability, you admit that it is true. Assumptions or assertions are not proofs, nor even arguments.

3. Delayed perception of events occurs frequently, but does not mean representationalism is true.

If you have ever watched a lightning storm or observed artillery fire, then you have perceived delayed perception. You see the lightning or the muzzle flash...then you hear the sound produced by the event. You hear thunder; you hear the detonation of the powder charge. To my knowledge, no one has ever argued that because of this delay, we hear only a representation of the thunder, or the detonation.

We notice these "delay" phenomena because the speed of light is much faster than the speed of sound. We compare the delay between the flash and bang. Yet we do not doubt that we are perceiving the same event through different senses. For that matter, we know that even light has a finite velocity, and our perception of the flash is also delayed--though there is no way we can observe this delay; not only is the delay infinitesimal, but there is no faster way to find out that any event has occurred, other than by light. As I stated in an earlier post, our visual perception would suffer this delay, even if we assumed vision was instantaneous. So if delay means that we do not see "directly", then we would still be, as you say, "...the victim of an extraordinary illusion"--even if the machinery of perception were itself instantaneous.

4. Smelling a Rat

Philosophers like to concentrate on vision, so I was gratified that you mentioned the sense of smell near the end of your full paper:

"It therefore takes a great conscious effort to remain aware as you walk down a street, for example, that all of what you are directly experiencing perceptually is merely a real-time, multi-sensory mental simulation of the world around you and your own body: the sight of the street scene around you...the smell of exhaust fumes..."

I simply must ask: do you smell the fumes of the past? Do you really smell fumes, or only a mental representation of fumes?

Suppose you smell gas in your rooms. Ordinarily, this would indicate some sort of emergency. However, because we are subject to deceptive illusions, perhaps the gas leak has stopped (assuming it existed at all). After all, how long does it take for odors to travel from their source to your nose? There's no point in declaring an emergency over some gas of the past. Best light a pipe to aid in the analysis of this philosophical puzzle.