Well, yes, a lot depends on what we assume the upload includes, and how important the missing stuff is.
If Dave!upload doesn't include X1, and X2 defines Dave!original's humanity, and X1 contains X2, then Dave!upload isn't human... more or less tautologically.
We can certainly argue about whether our experiences of hunger, thirst, fatigue, etc. qualify as X1, X2, or both... or, more generally, whether anything does. I'm not nearly as confident as you sound about either of those things.
But I'm not sure that matters.
Let's posit for the sake of comity that there exists some set of experiences that qualify for X2. Maybe it's hunger, thirst, fatigue, etc. as you suggest. Maybe it's curiosity. Maybe it's boredom. Maybe human value is complex and X2 actually includes a carefully balanced brew of a thousand different things, many of which we don't have words for.
Whatever it is, if it's important to us that uploads be human, then we should design our uploads so that they have X2. Right?
But you seem to be taking it for granted that whatever X2 turns out to be, uploads won't experience X2.
Why?
Just because you can experience something someone else can does not mean that you are of the same type. Belonging to a class of objects (ex. Humans) requires you to be one. A simulation of a piece of wood (visual texture, graphics, molecular structure, etc.) is not a piece of wood and so does not belong to the class of pieces of wood. A simulated piece of wood can experience simulated burning process or any other wood-suitable experience, but it is still not a piece of wood. Likewise a piece of software is by definition not a human being, it is at best a simulation of one.
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A list of some posts that are pretty awesome
I recommend the major sequences to everybody, but I realize how daunting they look at first. So for purposes of immediate gratification, the following posts are particularly interesting/illuminating/provocative and don't require any previous reading:
More suggestions are welcome! Or just check out the top-rated posts from the history of Less Wrong. Most posts at +50 or more are well worth your time.
Welcome to Less Wrong, and we look forward to hearing from you throughout the site!
Note from orthonormal: MBlume and other contributors wrote the original version of this welcome post, and I've edited it a fair bit. If there's anything I should add or update on this post (especially broken links), please send me a private message—I may not notice a comment on the post. Finally, once this gets past 500 comments, anyone is welcome to copy and edit this intro to start the next welcome thread.