Shall we discuss hard epistemology? Fine.
> You have no idea how he got to his position
False. I cannot prove how. The objection is pure sophistry. Were I to ask him, "how did you arrive at this position", his answer could be a lie. Would you commit the fundamental attribution error and assume that he would tell the truth? Perhaps he secretly doesn't even believe what he claimed to believe!
I doubt very much that you live your life doubting all things beyond your own thoughts. Trotting out a single fallacy mode and applying it in a scope carefully limited to bolster your argument is a rhetorical method for scoring debate points, not sound logic.
You are attempting to use "intellectual honesty" as a cudgel. Who wouldn't want to be intellectually honest?! Of course, you'll be the judge of when someone has met the criteria for honesty, and that will depend on whether they agree with you or not.
I am under no misunderstanding as to what I can and cannot know. I am completely comfortable with using mental shorthand to navigate the world. I do not need to stop and listen to every individual born-again christian to discover if they are the one that holds the key to my finally knowing the truth.
I do, in fact, have a very good idea as to how Thiel arrived at his position. I have a very good idea about why Strom Thurmond opposed the civil rights act of 1964. I have a very good idea that the sun will rise tomorrow.
> you go on this big rant that places you above him in terms of virtue
Yes, precisely. We all hold values. I find his to be in conflict with mine.