I've kind of come to the point of view that part-ness is the quality of non-intelligibility without the whole object. We usually think of the liver as a "part" of a human body and an isolated liver doesn't make any sense (indeed, an isolated liver cannot even continue existing as a liver). Essential to this view is that part-hood is relational and, consequently, not a fixed property of things per se.
I'm not a philosopher, but I do like to think about mereology.
What about things that are a part of one thing but also a part of something different? Molecules can be part of a bird or a pen or even independant. In such a case a bird requires molecules but molecules don't require a bird.
Yes. I suspect that nobody involved in this kind of thought process would argue with that.
While the liver is outside the human body it is no longer being a liver for a human body. It is in some other state
If we took a human kidney and used some scifi technology to use it as the functional component of a dialysis machine, does the nature of the kidney change while the dialysis machine is in use, vs. at rest?
If we transplant another animals liver into a human (maybe invoking scifi — I don't know where we're at with transgenics research) does it become a human liver or is it always a pig liver in a human?
What is the point of such philosophy? It's not "search of truth" because it doesn't care about the reality, it only cares about categorizing things into arbitrary structures.
It's like arguing whether a particular cloud resembles a dog more than a cat. It's neither, and it doesn't matter.
Putting a precise point on what our intuitions about how fundamental things works has, in the past, anyway, been useful for advances in physics. For instance, the question of mereology is pretty important in quantum mechanics. In regular mechanics the observable quantities that you put into the action have a local quality to them: if the positions of particles in your action are "distant" (in terms of the speed of light) then there is a precise sense in which you can consider those different parts of the action separately. That is, "distant objects do not form wholes." In a special relativistic context, events outside of eachother's light cones cannot participate in a "part-whole" relation with one another in a little local area around themselves.
In quantum mechanics this doesn't appear to be true, at least in a naive way. Superposition means that something like a "part-whole" relation can persist even when events relating to it are outside of eachother's light cones. One way of justifying continued meditation on mereology is to suggest that maybe something about our understanding of mereology is wrong, despite what is "obvious" to us.
I don't understand the philosophical terminology used here, but I do know QM. I find it highly suspicious that you claim philosophy is useful in QM given that we have contradictory interpretations of QM that all fit the equations and experimental data and provide exactly the same predictions about reality.
Yeah, but quantum mechanics and general relativity (arguably just QM and special relativity) don't make sense. Talk to any theoretical physicist at the frontier of quantum field theory or quantum gravity and you will meet people very interested in basic philosophical questions.
If all you care about is laying a bra against a ket or calculating scattering amplitudes I suppose the philosophical questions are far away from you, in more or less the same way that one could employ epicicular models to calculate planetary motion with as good or better accuracy that using general relativity. But if you want to _understand_ the motion of heavenly bodies you must do more than just calculate.
> Yeah, but quantum mechanics and general relativity (arguably just QM and special relativity) don't make sense.
It won't suddenly start making sense if we stare at it long enough. We have to change our assumptions.
I'm a fan of the Dragan and Ekert paper that derives QM axioms from relativity. The only thing you have to sacrifice is the ban on superluminal observers :) No philosophy required, just relax the "common sense constraints" on the solutions for relativity. Of course - it can very well be wrong. But I like it cause it's quite elegant.
> But if you want to _understand_ the motion of heavenly bodies you must do more than just calculate.
AFAIR the arguments in favor of geocentric models were philosophical, the arguments against it were experimental. We moved forward when we ignored what makes sense, and focused on what the data is.
Similarly we assumed absolute spacetime cause it made sense, and only accepted it's relative when data forced us to.
I love HN topics+comments. Not only is it it my daily reading, but I can easily imagine a high school or college discussion class centered on it as part of a truly liberal education.
I'm not a philosopher, but I do like to think about mereology.