Originally posted by CP5670
Exactly, but when did I say anything about not making other observations? I simply said that this direct one you talk of was not necessary. The very fact that we are measuring it once and getting a meaningful result out of it means that there is change right there; remember that we need some control to measure, so we must have seen a similar thing before.
I did. I'm not interested in what is happening to the glass, whether liquid is going in or out or anything else you care to imagine. I care only about whether the thing is filled to 50% capacity at the present moment. Whatever changes might be happening and whatever rules govern those changes are irrelevant: I care only for whether the glass and its contents are in this state, not how they got that way.
I never said that it was not so; I was talking about the general concept of observation at the elementary particle level, where the theory is just as accurate as any practical observation. Since our theories are far less developed at this larger level than are our observational capabilities, it would usually be more accurate to directly observe in some way, but what I am saying is that this is not true as a general rule. (although why you brought that up here in the first place is beyond me)
I never said you did say so. I don't think we've been on the same page this whole time. My entire concern is with the state of the glass at a particular moment. Changes occuring through time are of no importance, becasue I don't care how the glass was 1 second ago, nor how it will be 1 second from now -- I care only whether at this present instant it is 50% full.
That is still a theory; what more than mental involvement and analysis is a theory then? Are you saying that it is some fully tangible thing? Although this is true to some extent, the theory can be interpreted in too many different ways (using different axioms) to call it anything more than an ideal analysis.
Theories involve propositions. Categories of thought do not. A theory is something like "If I eat this sandwich, I won't be hungry anymore," or "Force equals mass times acceleration." A category of thought is merely a basic, irreducible mental concept like "quantity," "identity," "causality," "substantiality," etc. We make propositions using these, and can even make self-referential propositions about them, but in themselves they are basic.
um, we are talking about this particular observation; all you have to do here is to use an observation that has been done with better precision to theorize about another event that cannot be accurately observed so easily. I did not say that it is possible to get an exact result, but that it is possible to get a more accurate result.
We are still left with an inaccurate description of the situation. As long as we are willing to admit that our description of the glass's state is only an approximation of reality, I have no problem with anything.
Also, anything is hypothetically possible since it is just a hypothesis; that first sentence is messed up. 
Touche.
That amounts to the same thing;
No it doesn't. Experimental science is used to check whether our theories roughly correspond to reality, and in that sense it is very useful. But it's purpose is to keep theory close to reality. If we could get perfect measurements we could keep theory perfectly in line (not necessarily true, but in line) with reality, and could also dissolve the basis for my original objection. But the fact that we cannot get perfect measurements does not negate the meaingfulness of experimental science to its intended purpose -- getting an accurate as possible measurement of the contents of the glass would only be a means to the end, not the end itself.
it was given (or rather, implied, since I think he assumed that you had heard the question before) that the glass was 50% full. Of course, I still think that this given statement should be been explicitly stated there, but this has nothing to do with real/non-real glasses, hypothetical situations or whatever else you brought up;
It has everything to do with them. If we are making an assumption about the glass and then discussing it, we are no longer talking about the real glass, but about the ideal glass. We're talking about a hypothetical situation.
it is a simple logical problem that it is intended to reveal the second assumption, which varies from person to person.
I know what it is for, I'm just being a pain in the ass.

And what exactly do you mean by "shown?"
Demonstrated with complete certitude.
The second statement would be correct for an "ideal" thinking machine that only has a one-way link between the knowledge store and the analytic portion, but it does not apply to humans unfortunately.
That we interpret data through our categories to render them intelligible to our minds I do not dispute. I don't agree that the theories (i.e. propositional statements, see above) we hold are necessary to the raw processing of the data by our senses, and now that we've distinguished them I'm sure you'll see what I mean in that regard.
But in the entire discussion I have have been precisely unconcerned with how we assume the glass to be, and entirely concerned with how the glass is in itself.
Anyway, now that I've had my fun (see "pain in the ass" comment above), I'll point out the real flaw in all my argument from the beginning, and thus depart: In all my brouhaha about the real vs. the assumed glass, I was talking nonsense, since there never was a real glass! The existence of the glass was already a hypothetic, so quibbles about being able to determine its precise fullness never applied -- there was nothing to inaccurately measure.
