1.  But like I said, even without trusting any sensory data, you still remember receiving the sensory data.  So if you don't believe that time has passed, then everything prior to this very instant is a false memory (not just true memory of false data), and indeed any thought you happen to be thinking was constructed as part of it.  In fact, not only can you never construct any logical argument (due to your disagreement with C) but you cannot trust any preconstructed logical argument because if your memories are false then whatever agency falsified them may have left holes in your thesis.  Anything you aren't thinking specifically about this very instant is an untrustable blind spot. 

2.  No, I disagree.  Sensory data cannot reasonably support all theories, as some do not adequately explain it.

I'll try to make this reply slightly less long-winded, because eventually I'm not going to be able to get around the fact that all of my arguments will rely on judgements of sensory data.  (And of course, my contention is that yours do as well.)

To that, a person might say "Of course it can."

"Prove it," I'd say.

They then work up an extraordinarily detailed proof, involving all sorts of evidence, etc.  I take one look and say, "But you've used language to try to communicate your idea, which I reject.  Therefore, your 'proof' is either invalid or circular."

To that, they respond, "But your initial claim--that 'language cannot communicate ideas'--itself rested upon an implicit assumption that language can, in fact, communicate ideas."

And that's where I think we are.  I believe that what you're saying is tantamount to this:

"Based on all of the experiences I've had in my life--everything I've sensed and the judgements I've made based on those sensations--I conclude that such judgements are arbitrary and unreliable."

I feel as though, were I to ask you for any "evidence" to back up your assertions, the only possible evidence you could produce would rely on the very things you claim to disprove, i.e. an implicit assumption that we see, touch, hear, etc., and can make valid judgements on that basis.

Otherwise, if we were to give a temporary "agreement" to your stance, then your own argument would be completely arbitrary (as there'd be no good reason to believe what you have to say, or anything else), and would collapse in on itself in paradox.  In other words, as soon as we conclude that all judgement is arbitrary, we're robbed of anything that would give meaning to such a claim.

Consistent with what?

I think you mean internally consistent, as within the syllogism you later supply.  But the only consistency that really matters vis-a-vis philosophy is consistency with reality.  I believe that if you truly take something other than sensory data as axiomatic... let's say you conclude, arbitraily (via coin flip?), that arsenic is a healthy drink, and you drink it... well, your conclusion was not consistent, ultimately, with reality.

That's why you've made the choice to "assume" empricism, and so have I, and so have so many others... and why only Two-Face lives his life according to the cast of a coin.  Because the latter method simply doesn't work very well.

This is an example of deductive logic.  Deductive logic works when the premises are, themselves, true.  But deductive logic is not logic entire; there is also inductive logic, which is the method by which we arrive at statements such as "all cows eat meat."

Appropriate for our discussion, inductive logic rests squarely on... the judgements we make based on our sensory data (e.g. have you ever known a cow to not eat meat?).  So, I think it's safe to assume that you feel comfortable in rejecting inductive logic as a discipline altogether.

However, deductive logic--the internal consistency that you believe stands for all consistency--is completely meaningless without inductive logic.  If we can never know the truth of the premises (which I think is another way of formulating your argument), then what do our conclusions possibly matter?

Our beliefs must be reconciled to the reality around us because we wish to live, and avoid arsenic.

Or, if you have another goal--say death--then consistency (in my sense, not yours) is still important in order to find arsenic and carry it out.  Though I'll admit; death is easier to come by through an arbitrary belief system than is life.

But it's my contention that no such theist actually exists.  (You: "based on, what?  Empiricism, right?"   Me: "Of course--there is no other way.")

While ultimately (if I'm correct in my atheism), a theist will eventually reach a point where he finds that his theistic views are inconsistent with the evidence of his senses, and will have to reject one of them, I don't believe that it is a rejection of empiricism that ever leads a theist to his theism.

Instead, I believe that a theist initially believes in god because he believes that it is somehow consistent according to his experiences.  But, like I said long ago in this discussion, empiricism doesn't mean that people don't make mistakes in their judgements... and, as an atheist, I believe that theism is just such a mistake.

As an example for all of this, I believe that the seasons were witnessed before Persephone was "created"; not the other-way around.

Well... I dunno if I managed to be less long-winded or not, but I'll have to leave the field for now, at least temporarily; this is a wonderful discussion that has done incredible damage to the work and chores I've needed to do over the last few days. :)

1.  But if you are working on the tenth step of a logical problem, and you didn't actually do the first nine steps but only think you did, there is no assurance that the entity behind this deception did them correctly.  So the logic is not dependent on you actually doing the work, but the logic may be invalid. 

2.  But if you posit "the world is exactly as I sense it and the Moon is made of green cheese" and you go to the Moon and it is not in fact made of cheese of any color at all, then sense data does not support that view.  I think you are blinding yourself to all the nonsense views precisely because they are inconsistent with empirical evidence, but when you say "ANY theory" you have to mean it.

1.  If you think you did, you did.  If you didn't (that is, actually forgot what premesis you were using), you would find yourself not being able to make a conclusion, as you didn't know your premesis (I'm referring to premise-premise-conclusion, the method of logic).  You could suddenly have an altered premise, but that would also alter your conclusion, so whatever conclusion you have now would follow.

2.  Sense data, as we agreed, does not say anything in and of itself; it's our judgements, and our judgements are arbitrary.  So when we got to the moon, we could say of what we sensed "Ah ha, green cheese indeed!" or we could say something else.  My point is, there is no reason to suppose that our sense data supports any view we have, as whatever judgement process we have cannot subject itself to itself without assuming itself.

 Itself

1. You don't understand.  What if there is faulty logic in between the premises and the conclusion, in the part of the work that was implanted memory?  Or what if (as you say) a premise was suddenly altered, but the work didn't adjust itself to cope with the new data and therefore became invalid?  You are assuming that your logic would dynamically adjust itself to handle the alteration but this is simply not the case. 

Like this:  "Here is a kitten / Kittens are cute / The being in the first premise is cute" is altered to become "Here is a chicken / Kittens are cute / The being in the first premise is cute"

You can never double check sufficiently to correct for this, because every time you turn your back it could be screwed with. 

2.  As far as I can tell you are proposing that a fantasy world cannot contradict itself beyond reconciliation.  I disagree.  Basically the dreamer you posit is changing the definitions whenever his senses contradict his worldview, which doesn't count.  (Perhaps it might be better to say, it dodges the point that the previous view was in fact contradicted by the senses.)

1.  Well, the example is necessarily very short, but I'm thinking of doing more lengthy thinking.  With a long problem you rely on your memory to hold information about what you've taken from the premises and deduced into new premises.  For instance, if you have two sets of premises that you work on separately and later combine the results to solve the problem.  You are presuming that you will go back and double check to see that you haven't made any mistakes (or had any made for you).  But no matter how many times you check, if your memory is untrustable there is ALWAYS the possibility of something being missing/wrong. 

2.  But the just because the senses don't prove anything absolutely doesn't mean they don't prove anything relatively, as in "assuming the senses are accurate then this is wrong".  So any worldview that includes the position that the senses are accurate could have its validity challenged by contradictory sensory input. 

If I have the idea that my perceptions are roughly accurate, and that a rock is as I percieve a rock and cheese is as I percieve cheese (and that they are very different), and that the moon is made of cheese, and I percieve that the moon is made of what I percieve to be as rock, then part of my worldview (either my definition of cheese or my view of what the moon is made of or my view of the accuracy of my senses) is wrong. 

This is why we do NOT agree here.  Just because senses can't ABSOLUTELY PROVE that a worldview is the true really for real truth, that doesn't mean that they can't prove that a worldview is not consistent with sensory data.  (This is what I mean by senses "contradicting" a worldview:  to say that something else is the case.  That doesn't necessarily mean that the senses win the disagreement.)  And, if part of the worldview is that sensory data will agree with the worldview, thus contradict itself.  Your position (in the final sentence) is only true of a worldview that gives no credence to sensory data.