Sunday, December 26, 2010

"Bonald" comments (link via the Western Confucian) on the same article by Stephen Barr which I wrote on here: "The example he gives is the band structure in metals. This is certainly formal, although metals don’t have the intrinsic teleology or indivisible unity of biological substantial forms. What we need is a sort of weaker idea of form for this lower order of being, one without teleology."

Is a pure body of water, or a metal lattice a substance? Or just a group of individuals? Or something in between?  Associations other than substantial unities have form, but it is an accidental form, not a substantial form. But an accidental form will have some sort of teleology. But it should also be said that discerning the end of something can be difficult for us, especially if we are trying to determine remote ends rather than proximate ends. But I do not think that is the problem we have with electronic band structure, since we are looking at potencies and actualities of parts of a whole. How much can a part be actualized before it is no longer a part of that whole? It seems to me that electronic band structure is just the quantification of those actualities. (James Chastek has this relevant post: Quantitative and logical parts.)

10 comments:

Zac said...

Hi again Papabear,

I wrote an email to Stephen Barr about that article; glad to see it discussed here.

As a novice metaphysician, please tell me if I'm out of my depth!

My resolution of the metal problem was that metals are themselves substances in their own right. It is incorrect to say that electrons and crystal lattices of atoms exist within metal (as substances); just as it is incorrect to say that hydrogen and oxygen exist within water (as substances).

I've read it phrased as such: hydrogen and oxygen atoms are 'virtually present' within water molecules. But they are not substantially present. If we stick to the level of actual substances, the issue of causation does not present the problems that Barr suggests. 'Electronic band structure' merely describes the qualities of the metal substance on a very fine, qualitative level, whereas Aristotle's causation operates on a substantial level.

Is this what you mean by "It seems to me that electronic band structure is just the quantification of those actualities."?

I like this line from your original post: "Aristotelian-Thomistic vocabulary begins with what we first know and it is used to understand what we come to know."

That is a great summary of the difference in world view, from my limited experience. The opposite view leads to strange thoughts in high-school chemistry classes along the lines of:
"Ah, I see! Water is really just hydrogen and oxygen!!"

Kind regards,

Zac

papabear said...

Zac, thank you again for your comments. I agree with what you said about the virtual presence of parts in a whole.

"'Electronic band structure' is just the quantification of those actualities'" is an attempt to reformulate "Electronic band structure describes the energy levels of electron atomic orbitals."

Some more thoughts --

I do not know if they are better said to reflect the qualities of the whole substance rather than qualities of its parts (as potential wholes). Can we say that the higher energy levels represent a decreased stability of the substance?

The characteristic band structure of metals is different from that of semiconductors or insulators. It reflects differences in how substances (especially substances of the same kind) interact with each other. How do we understand the flow of electrons -- as the movement of substances or as the transmission of a quality between substances?

I haven't yet worked out answers to these questions...

Zac said...

Sorry for my late response!

Douglas P. McManaman - the writer you've linked to in the more recent post - has been my most valuable resource in trying to understand hylomorphic dualism. There are additional resources on this page: http://www.lifeissues.net/writers/mcm/ph/ph_01philosophyyouth1.html

The title belies the advanced nature of the topic!

"I do not know if they are better said to reflect the qualities of the whole substance rather than qualities of its parts (as potential wholes)."

My understanding is that the whole determines the parts, and that all qualities are substantial qualities. So, though we are attempted to ascribe qualities to the electron, this would wrongly imply that the electron is the substance. But electrons do not have such qualities on their own...

If you'll forgive a poor analogy: I can click my fingers, but if my fingers were severed,they would not click themselves. The ability of 'Clicking' is therefore a quality of mine, as substance.
This analogy is limited, but I think it helps a little.

The more I think about this area, the less reality or prominence I attribute to the 'parts' of a substance.

"How do we understand the flow of electrons -- as the movement of substances or as the transmission of a quality between substances?"

This is a tricky one, because we are so used to thinking of electric current in terms of electron flow, as though the metal is an inert conduit for the movement of other substances.

I think we need to see the phenomenon of electricity as a quality or property of the 'conductive' substances. The only time we would view the electron itself as a substance would be at the point it is transmitted from one conductor to another.

That's the best I can do at this stage...

Regards,

Zac

papabear said...

"My understanding is that the whole determines the parts, and that all qualities are substantial qualities. So, though we are attempted to ascribe qualities to the electron, this would wrongly imply that the electron is the substance. But electrons do not have such qualities on their own..."

I agree with this, but I think with respect to the energy levels, we are referring to electrons as potential wholes in themselves rather than as parts. So can an electron be said to have a quality, not as a substance in its own right, but as a potential whole or substance? This would be more clear if it were obviously the case that an electron cannot have a higher energy level without destabilizing the whole.

I am assuming for the moment that electrons in isolation from atoms do have some sort of substantial reality.

Zac said...

"I am assuming for the moment that electrons in isolation from atoms do have some sort of substantial reality."

Yes, my understanding is that an electron in isolation is a substance. Just as an atom in isolation is a substance. McManaman points out somewhere that subatomic particles behave differently when isolated vs 'within' an atom.

http://fmmh.ycdsb.ca/teachers/F00027452/F00027453/physicsandphilosophy.html#BM65__Oxygen__18__Carbon__10__Hydrogen

"So can an electron be said to have a quality, not as a substance in its own right, but as a potential whole or substance?"

In the above link, McManaman states that "there is no hydrogen in water", and by extension I would be inclined to state that there are no electrons in a metal. But as he goes on to quote (someone else):
"The lower degrees of mobility in nature are always apparent in the higher, but in their more elevated form they are dominated by the higher reality in which they are, expressing its nature and cooperating in its actions. They are not expelled from existence in their adopted homes, but they are, as shown by the unity of the whole in which they reside, more indeterminately and subordinately present than when they existed in isolation"

Now, I'm very much beyond the limits of my scientific knowledge, but if you'll forgive me quoting wikipedia (which I only do when there's a sound footnote):

"In reality the particles that are commonly termed electrons in metals and other solids are quasi-electrons—quasi-particles, which have the same electrical charge, spin and magnetic moment as real electrons but may have a different mass."

So it appears that referring to these parts of a metal as 'electrons' is technically inaccurate, like referring to the parts of water as 'hydrogen' and 'oxygen'. We do it for convenience, but it creates metaphysical confusion.

I think I understand where you're coming from in terms of wanting to ascribe qualities to the 'quasi-electrons' as potential substances, but it feels a bit like a blurring of the lines.

Personally, I would feel clearer about it if I started with the substance (eg. copper) rather than starting with a subatomic particle that is only virtually present in copper. Then, we can carefully define how the different parts of the thing called copper function, and in this way not lose sight of the substance level. It feels a bit more like biology in this sense - start with the whole animal and then examine/disect it.

Of course, you could try emailing McManaman with this question : )

Thanks for your patience with my drawn-out thought process!

Zac

Zac said...

The URL broke...but if you go here:

http://fmmh.ycdsb.ca/teachers/F00027452/F00027453/physicsandphilosophy.html

and click on:

"That simpler forms are somehow in compounds"

it's about the tenth one.

papabear said...

Hi Zac, thanks again for your responses--you bring up good points and I don't disagree with what you have written. Just to expand a bit more on instability -- I think the data could be interpreted as follows: as "electrons" get more energy, they become more "actualized" (until they become fully actualized when they escape the whole) while the whole becomes more unstable. (Which would lead to the question of whether ions are of the same kind as the neutral atoms or not.)

But I haven't accepted that model of the atom yet, so this is just a dialectical inquiry into what physicists say. Might it be possible that the data be interpreted in such a way that electrons have no reality as substances and are just poorly-understood causes of measurements? I haven't ruled that out yet.

Thanks for giving me the opportunity to think a bit more about these topics -- I haven't been able to devote much time to questions of physics.

Zac said...

"Might it be possible that the data be interpreted in such a way that electrons have no reality as substances and are just poorly-understood causes of measurements? I haven't ruled that out yet."

Seems like a fair approach, and is certainly more suitable to the existence of 'electrons' within other substances.

This has been a good discussion. I feel I've a long way to go in Aristotelian metaphysics, and these difficult questions are a great prompt!

papabear said...

"This has been a good discussion. I feel I've a long way to go in Aristotelian metaphysics, and these difficult questions are a great prompt!"

Indeed, and so do I!

Alan Aversa said...

Read St. Thomas Aquinas's De Mixtione Elementorum and the Thomist article on it: "Elemental Virtual Presence in St. Thomas" by Christopher Decaen.