Philosophers have always wondered if what they perceive is actually the case. In other words, It’s not at all self evident that “existence exists” as you put it. Our sense could be in error, they could be lying to us. Or all of what we perceive could be the product of our imagination. Or it could all be a dream. There is no proof that could be offered for the accuracy of reality that could not be offered in a dream. Or we could be a brain in a vat of chemicals hooked up to electrodes that feed input into our minds, and what we perceive doesn’t really exist but is rather a projection foisted upon us by someone else. There is nothing that cannot be cast upon with doubt. Therefore, to say that error in perception is impossible is actually a statement of faith. And saying that what we perceive is real and true instead of any one of the falsities it could be is just cherry picking. As you quoted from Anton Thorn, “Things are what they are regardless of anyone’s wishes…” Perception may not be, as you say, the pre-conceptual awareness of an object, but rather the awareness of a falsity we take to be the truth. So faith would be in play when it comes to the perception of objects or to the experiencing of something if you take it to be accurate.
You say, “It is certainly true that one can *cast* doubt upon all sorts of things. But that doesn’t mean such uncertainty has any basis in reality; i.e., that such uncertainty has any truth value, i.e., actually obtains or is rational. I can doubt that I’m actually staring at a computer screen as I type this right now. Jodi Arias can doubt she’s a convicted murderer.” But, I don’t have to show that what we perceive is a falsity in order to question perceptual infallibility; I only have to show that falsity is a possibility. Even you say it is possible, as indicated by the first line of this paragraph, therefore, perception is not infallible. Saying it has no basis in reality though is begging the question, for that is the very thing in question. Are we perceiving truth or falsity?
You say “Peikoff addresses my complaint head on, when he writes: “It is possible, the skeptic argument declares, for man to be in error; therefore, it is possible that every individual is in error on every question. This argument is a non sequitur; it is an equivocation on the term ‘possible.’” And you go on to say, “what is possible to a species under some circumstances, is not necessarily possible to every individual member of that species under every set of circumstances. Thus, it is possible for a human being to run the mile in less than four minutes; and it is possible for a human being to be pregnant. I cannot, however, go over to a crippled gentleman in his wheelchair and say: ‘Perhaps you’ll give birth to a son next week, after you’ve run the mile to the hospital in 3.9 minutes — after all, you’re human, and it is possible for human beings to do these things.”
But this is wrong headed thinking. You are taking a specific conditional circumstance and showing how it does not apply to all humanity. But, Perception is not a specific conditional circumstance, it is the universal experience of mankind. As a universal, it can be universally in error. It would be a monumental achievement of you to show how a universal thing such as perception could not conceivably be a false experience. I don’t think you can prove that.
A man coming into contact with proof of something or other in this world would indeed, as you imply, be forced to accept the absolute truth of the matter. Man would no longer have a real choice in judging this or that to be right. The matter would be decided for him, and those who rebel against such proof would be considered madmen, detached from reality. The amazing thing is that you say that you have proof and have risen above skeptics and the religious alike. You quote, “for the sake of both the mystic and the skeptic, it’s best that their doctrines operate in the shadows, away from proof, for that is how faith and doubt thrive. To do otherwise and expose them to the shining light of reason, would cause them both to implode and, thereby, give away the game.” But the mystic and the skeptic understand reason, which is purported lately to be the only way of knowing everything, can only take them so far and no further. Through the shining light of reason they have not found proof. So, how is it that you can claim proof when no one else can? It’s by claiming perception cannot possibly be in error. But, let’s examine this a bit more.
You say that the basis of all man’s knowledge is the perceptual stage. From that basis we form concepts which allow us to state propositions which then may or may not be used to form a certain knowledge. So, you have a hierarchical series of percepts to concepts to propositions to knowledge. Each member in the series is supported by the previous member and this series is able to stand on its own because the base is infallible. In other words, we are not allowed to ask, “what supports the first member in the series, the perceptual stage?” We are asked to believe it stands on its own, that it is infallible. It’s a bit like saying, “No one may do anything (including asking for permission) without asking for permission.” But, what’s really going on here?
Imagine a small number of circus performers underneath a big top. Their act consists of standing on each other’s shoulders. The second person stands on the first, the third stands on the second and so on until the last member stands on the top. What’s amazing about this act is that the first performer does not stand on anything else. The second member all the way to the topmost member do not worry about this because the top member has told them that the first member is fully capable of holding them all up without anything holding him up. Each member in the series is supported by another member and they are able somehow to stand on their own. The first member supports himself. It’s quite an amazing act.
Such is the case with your hierarchy that brings you certain knowledge. But, your act gets a bit weirder. The last member of your series is certain of this proposition, “Any “error” or “uncertainty” at the perceptual stage [first member] would be an impossibility” and has caused all the members of the circus act to bend in such a way so the hands of the last member can grab the feet of the first member thereby validating the infallibility of the first member. They have formed a circle. Now the act is even more amazing because it is still suspended in mid air. It supports itself. But just like all other acts in the circus, it is not to be believed, only wondered at.
The mystic and the skeptic both recognize the circular quality of such philosophies. The mystics find some philosophies that can be made straight and ground them upon a transcendent foundation: faith in God. The skeptics reject all philosophies that are circular and are forever trying to search for or invent philosophies that aren’t. But in this way, they are like restless nomads going from unsatisfying tent to unsatisfying tent. They begin to rest when they rest upon foundations which they cannot see. And it is in this way that all Christians feel that their real home lies in another country of which their senses cannot testify.