You seem to doing the same thing that you accuse iano of doing...
That is:
Not being able to tell the difference, yet assuming there
is a difference.
You say:
If both manifest the same way, the same logic applies in describing them both. Only in places where the two would of necessity be different (which, you assert, is nowhere) would this line of reasoning be in any way meaningful.
and then you conclude:
Therefore, if reality is objective and external, the interpretation of reality that is most objective and external is most likely to be correct. Well, seeing how religion relies on personal feelings and interpretations, while science relies on outside observation and repeatability, I submit that science is more objective and more external. So, here are the two options that this entire line of reasoning permits:
(1) Subjective reality: We're both wrong
(2) Objective reality: You're wrong
Don't you, in arriving at your conclusion, assume a difference here:
So, the question is, either the "external reality" is the right boat, or it's the wrong boat. If it's wrong, then both theists and atheists are wrong together. If it's not wrong, at least one of us is still wrong (because, in an external, objective reality, we can't both be right).
So, we're only in the same boat if we're all wrong. This doesn't drive the argument to stalemate, because it only stalemates under the condition that everybody's wrong. This effectively polarizes the argument (i.e. leaves no room for middle ground).
Maybe I'm missing the difference you must have pointed out?
Here you said:
Both theistic and atheistic approaches depend upon some external source of reality. This, you believe, puts us in the same boat, and renders all our claims about reality utterly subjective and completely equal in validity. I can understand this logic. That boat is the "external reality" boat (as opposed to the "subjective reality" boat).
If "all our claims about reality utterly subjective and completely equal in validity" then how is the boat the ""external reality" boat"?