I've been rather busy over the last few days, but I wanted to get a response to you here before things get even busier for me over the coming weeks.
I wrote: <<<Gravity, for instance, is non-physical, but I can experience this with my senses (such as when I pick up a book, I feel the pull of the earth's gravity affecting the book; I do not see gravity, but I sure do feel it).>>>
Peter responded: "This statement here, 'I do not see gravity, but I sure do feel it', seems to be saying that what can be felt is not necessarily physical, but what can be seen is. I do not think this is what you mean, but this is unclear."
By 'feel' in the statement I made I mean tactile sensation, as something brushing against my skin (e.g., wind) or the weight of something when I pick it up (e.g., gravity). I am not referring to feelings in the sense of emotions (which some people confuse as a mode of cognition). My point here is to draw attention to the fact that even if I consider something non-physical, we can sense it by one of our five senses. Does the 'supernatural' behave that way? Well, let those who claim that there is a 'supernatural' something answer this question, and provide evidence supporting the point on behalf of which they want to argue.
Peter asked: "If something is non-physical if it can be felt but not seen, would that not make air non-physical?"
I think this is a scientific question. However, my armchair analysis would be that air is a physical attribute of the atmosphere, which is a property of the earth. Objectivism does not hold that air is an entity.
I wrote: <<<How else would we be able to determine that something exists, if we cannot perceive it in some manner?>>>
Peter responded: "I hope you understand the difference between knowing something exists and the reality of something existing (after all, it is part of the axioms of Objectivism). I still want to see the reason that you can assert that we are fully capable of knowing the facts of reality to such an extent that the supernatural is denied."
Well, Peter, be honest, you're simply going to poo-poo anything I have to say on this matter, because you would consider it a threat to your beloved god-beliefs. Besides, I think it's clear already that you reject reason, so what would be the point? If you want to pursue this matter, why don't you tell us what you mean by 'supernatural' (i.e., tell us what it is, and not simply what it is not - be as specific as possible) and argue for its reality (e.g., explain how its existence can be scientifically verified)? If you claim that the 'supernatural' actually exists, then you should argue for this positive claim (so that we do not conclude that the 'supernatural' is simply another mystic fantasy). Otherwise, I might as well consider the point conceded to me.
I wrote: <<<Yes, I do accept that there is non-physical existence, but in each instance I recognize that the non-physical is in one way or another dependent upon something that is physical.>>>
Peter asked: "Is this a reasonable conclusion to make?"
Given the data sets which I have, I think it is the only conclusion to make, and that it is reasonable within the context available to me.
Peter asked: "Is it impossible for there to be non-physical existence independent of something else that is physical?"
I would tend to agree with this since I am not aware of anything which exists and which is wholly non-physical and which is not in some way dependent upon that which is physical (such as gravity and consciousness are). To accept something as a possibility, I must have some supporting evidence, and I am aware of none. But if you have a worthy counter-example which can be scientifically verified, by all means, cart it out for us to examine. I think that's a reasonable request, don't you?
Peter asked: "Isn't there a possibility that something physical could actually be dependent upon something non-physical?"
I would have to have some evidence for this hypothesis. If you have evidence for this, please identify it, and let's examine the quality of this supposed evidence. If there is no evidence for this, then on what basis would I entertain this hypothesis as a legitimate possibility? On no basis? On the basis of someone's imagination?
I wrote: <<<Furthermore, I do not accept the claim that there are non-physical entities; the non-physical is always an attribute of a physical entity. >>>
Peter responded: "This is a blanket statement asserting something positively--"the non-physical is always an attribute of a physical entity" (shifting emphasis for clarification). What reason do you have to assert this claim and to make it a universal claim?"
This is the result of my observations of what exists (i.e., my data sets). I cannot claim that something which I have never observed in some way or another, directly or indirectly, exists, particularly if it contradicts the general knowledge which I have validated. I tend to operate in the basic manner which George H. Smith describes in his book Atheism: The Case Against God, on page 103:
These are general principles which we derive from our experience.
Every instance of something I identify as "non-physical" has been an instance of an attribute of a physical entity. To overturn this inductive conclusion, all one needs to do is provide legitimate counter-evidence. Otherwise, you'll simply have to accept that this is my position on the matter, whether you think it is justified or not.
I wrote: <<<For instance, in the case of consciousness, I hold that consciousness is an attribute of man, where man is the indivisible entity possessing consciousness as an attribute.>>>
Peter asked: "But how does that make man necessarily physical?"
I don't think that any statement has the power to "make man necessarily physical." He is physical by virtue of his identity qua man. Otherwise, this simply sounds like a challenge to prove a negative (e.g., "Prove that man cannot be wholly non-physical! Now!!"), and I have no obligation to entertain such a challenge. If you have evidence to the contrary, then cart it out. If it is legitimate evidence, that would settle the matter. Otherwise, I consider it settled as is.
Peter asked: "Could a non-physical man exist holding to consciousness and still fit these qualifications? Logically, yes."
I would say that your use of logic is divorced from reference to reality, as Peikoff points out:
Any theory that propounds an opposition between the logical and the empirical, represents a failure to grasp the nature of logic and its role in human cognition. Man's knowledge is not acquired by logic apart from experience or by experience apart from logic, but by the application of logic to experience. All truths are the product of a logical identification of the facts of experience. ("The Analytic-Synthetic Dichotomy.")
Peter wrote: "You must first demonstrate that man must be a physical entity."
Why? What would you consider an acceptable demonstration? I don't think you would accept any such "demonstration" since you want to believe in some supernatural myth. That is why you put so many high-bar challenges up to those who do not share your beliefs. That's a cheap tactic. If you think that a wholly "non-physical man" is possible (which you seem to think is "logical"), why don't you hold yourself to the same standard which you expect others to meet, and demonstrate this man's existence? Please provide a clue on how you distinguish this person's supposed existence from a figment of your imagination.
Peter wrote: "From there, you must demonstrate that all non-physical existence is dependent upon a physical existence."
I think it is obvious (given what I know) that this is the case. Again, if you have counter-evidence, please provide it. I have no onus to "prove" that things must be the way they are. This is just another way of challenging me to prove a negative, which I will not accept. Do you assert that there is a non-physical man? If so, then cart out your evidence. If you don't, then I don't think it's an issue.
I wrote: <<<All these issues are dealt with in the Objectivist literature, Peter. You might be impressed by some of it if you were to examine it firsthand.>>>
Peter responded: "I have examined quite a bit of it, at least through the writings of Rand and on various Objectivists sites, etc. And while I certainly think it is more impressive than relativism, I do not think you have any reason to not be a relativist given the nature of Objectivist philosophy. I will not say any more at this point because I do not want to get off onto another subject until we are finished with this one!"
What exactly do you mean by "relativist" (different people seem to have differing ideas as to what this means, so I ask for clarification from you), and what are you trying to say here about Objectivism based on what little you know of it?