Your vocabulary lends itself to some fascinating interpretations of what "IS" is. THAT is why any debate with you ends up in a hair splitting exercise. What you DO with words is, as RE has pointed out repeatedly, move the definition goal posts around so that you can say, uh, NO "I didn't say that" or "No, this thread has no relevance to eXternalism", etc.
Instead of just accusing me of moving the goalposts, show me where I have.
FOLLOWED by your apparent willingness to discuss an issue, that by your own words, is rather fruitless to discuss (i.e. the interaction). 
It is not fruitless to discuss it, and in fact I welcome discussion of it, since I am pretty sure that the more people think about it, the more people will realize that the interaction problem has no solution, and so take a look at the alternative -- idealism. Of course they might also fall into the error of materialism, in which case I would welcome discussion of the hard problem of consciousness, which they can't solve.
Here's the deal, Ka. EVERYTHING about your outlook on what you consider WHATEVER is impossible to argue against BECAUSE you DO NOT REALLY BELIEVE (yeah - I know you'll claim that about you is incorrect as well) WE are talking to each other here.
Yup, incorrect. See below.
Sure, you can come up with all sorts of erudite labels with "justification" for your claim that you believe we do have sensory apparatus and that you do actually engage in debate with other humans and recognize that we talk to each other, but it is NOT SO, according to your concept of reality.
My concept of reality is that there is nothingness (no-thingness) AND there is thingness, and each depends on the other, making them a unity. So it does not follow from my concept of reality that there is no sensory apparatus, or other humans, or biosphere.
This then taints absolutely every subject on the issue (i.e. cause and effect related) about integrating, analyzing and taking appropriate action on, INFORMATION about the OUTSIDE world that our sensory apparatus MUST have for us to remain as viable homeostatic biological entities.
There is just NO WAY for you to look at your belief system and seriously consider the possibility that you are a space cadet living in a totally erroneous private world. The biosphere is NOT accessible through a meditation chamber, and never will be, IMHO. You have provided zero evidence that it is.
?? What does meditation have to do with the existence of anything?
Furthermore, you may even claim that "looking for evidence" is evidence
of an incorrect approach to "perceiving" the biosphere or anything else.
The only (non)-thing for which one cannot look for evidence is no-thingness. The biosphere is a thing, so there is no problem perceiving it, or studying it scientifically.
It's kind of like saying that jumping out of a window of a multistory building is not dangerous; it's the concrete that kills you. And even that was a mere perception of smacking the concrete. 
Ah, now here there is something to say. Yes, smacking the concrete is just perceptions, very painful ones, resulting in death, which is to say the scrunched up body is no longer able to perceive physical reality (its sensory apparatus has been destroyed). After which (I think) one perceives non-physical reality, but I can't prove that. In any case, physical reality continues to exist as long as there are people or bacteria perceiving it. The problem I suspect you have with this is the word "just" as in "just perceptions". My task, if we are to actually debate this, is to show that saying that physical reality is "just perceptions" does not detract an iota from science, or how we should engage with physical reality, for example, it remains the case that jumping out of high windows results in death.
When I question your ability to perceive without accepting the fact that perceiving IS a sensory EVENT that INCLUDES integrating outside information, you DANCE by saying the, uh, "interaction is not explained".
As I said, I accept that perceiving is a sensory event, and have no idea why you think I would think otherwise. And it does integrate outside information, that is, information that was outside my ego consciousness, and moves inside it. However, I would also say that "inside" and "outside" are spatial metaphors, and that space has no independent existence, that we create space, time, and mass in the act of perceiving. And this, of course, is where discussion gets tricky, and calls for "hair-splitting", though I would call it precision. The moon really exists, but only exists located in spacetime when it is looked at.
I'll tell you what. When you agree that it is possible that you are a space cadet and do not have a clue of what you speak, then I will admit that SAME possibility is present in my worldview as well. But until you, a separate and distinct entity from me, are actually willing to GO THERE, you are fibbin' when you claim you ARE willing to "go there" on the issue of eXternalism.
I agree that it is possible that I am wrong. There is no certainty in metaphysics. All one can do is argue over what is most plausible. But then I have never claimed otherwise, so I really don't understand this talk about being unwilling to "go there". After all, until I was 37 I was just as much an externalist as you are now. So I've been there.
I challenge your claim that eXternalism is not related to, or relevant to, this thread. It is.
Of course it is highly relevant to this thread, which is why I made my first post in this thread attacking externalism. However, it is not relevant to the debate I had with RE over the usage of 'ad hominem', which is all I claimed.
People who BELIEVE that there is ZERO meaning in anything and everything they "do" OFTEN end up committing suicide (e.g. Buddhists). THIS SENSELESS ACT is born of nihilism. ANYONE that teaches others that there is NOTHING because there is NO THING is nurturing a potential nihilist who may end up committing suicide.
Then I'm off the hook, because I definitely believe there are things, such as you, me, and the biosphere, and that real people are doing real harm to it. What I do not believe is that there are any mindless things existing on their own.
DON'T hair split with me about the importance of MEANING and PURPOSE in human lives. Your worldview EXCLUDES BOTH MEANING AND PURPOSE. But of, course, you will claim that you never said any of that or represent any of that. Well, I think you do. And I think you should take responsibility for telling people there is NOTHING to FEAR out there because there is NO THING, or even an "out there".
I am afraid of disease, poisonous critters, of losing my savings to some bankster, etc. etc., since I consider viruses, critters, and banksters to all be real. I also think that MEANING and PURPOSE are names of God, and that things exist to express that Meaning and fulfill divine Purpose.
You say I am moving goalposts. Show me where I have. Show me where I have ever said or implied that "nothing is real" or anything like that. Some Buddhists say that, but I am not one of them.