I wonder how you would define "atomic materialism", especially as opposed to mere "materialism"?
A brief Google suggests the term hasn't been used much since the 19th Century, but could mean either that everything is made of indivisible atoms, or that matter is made up of indivisible atoms. However, we've known for a long time that atoms are not indivisible.
Looking at your last link, perhaps you mean more that "everything is mass"? But quantum field theory as described in that article has been around since at least the 70s, and I think physicists and philosophers would still regard quantum field theory as a materialist theory. In modern usage, "materialism" is synonymous with "physicalism", i.e. that everything is physical [0]. Most physicists would call themselves materialists.
I ask because the same article was posted over a year ago and someone made a very similar looking comment [1].
> we've known for a long time that atoms are not indivisible.
I do not agree with your statement that "we've known for a long time that atoms are not indivisible." Lucretius makes very clear that atoms are forever indivisible entities. So, _by definition_, we call an indivisible object an atom. If it is divisible it is not an atom, according to the original definition of the word.
What happened is that, physicists named an object an "atom" and when they resolved that object they named "atom" into its constituent parts, they claimed to have divided an indivisible atom. No. This is only a play on words.
Unfortunately, we see this process of loading old words with new meanings in physics all the time. No definition is sacred in physics. As you wrote, "In modern usage, 'materialism' is synonymous with 'physicalism'." This simply means that physicists changed the meaning of the word "material."
This process confuses me a lot. I even have a short essay about why physics must be semantics.
I agree that terminology is especially fickle in physics, and it can be very confusing. Words need to be co-opted in order to discuss the objects of a new theory, and often they are simply chosen by rough analogy. The "mass" of Newton's spacetime is not the "mass" of Einstein's relativity. The "spin" of an electron is not the same as the spin of a car's wheel.
John Stewart Bell has a nice quotation about this when discussing the use of the word "measurement" in quantum theory:
> Take for example the “strangeness”, “charm”, and “beauty” of elementary particle physics. No one is taken in by this “baby talk”. ... Would that it were so with “measurement”. But in fact the word has had such a damaging effect on the discussion, that I think it should now be banned altogether in quantum mechanics.
As for atomism more broadly, now that I think about it there are some modern theoretical physicists with ideas about the discretisation of spacetime, for example: https://arxiv.org/abs/1312.2852
> I wonder how you would define "atomic materialism", especially as opposed to mere "materialism"?
Thanks for noting this distinction. Come to think of it and in light of what you wrote re physicalism, I would think that I want to distinguish the two kinds of materialism. The one is a vague and general notion (“everything is physical”) and the other is a well-defined view of the world. According to this view, there exists absolutely indivisible units called atoms and empty space where these atoms move. I think "atomic materialism" emphasizes that we are talking about a world made of indivisible atoms. I think the other view does not take indivisibility as a strict requirement.
Yeah, SEP is very useful but can have a slightly awkward perspective on these sorts of things. I intuitively think of physicalism as "That which is real is that which can be brought to the attention of the senses (directly or indirectly)". You need various caveats and elaborations to account for hallucinations and the like, but that's the basic idea I have in my head.
Hmm, then this definition of physical would also include traditional notions of deity, spirits and soul, since all are thought of as having indirect sensible effects.
You raise a good point. Cultural superstition is just the sort of thing that requires elaborations to the definition. It's much like the problem of demarcating science from pseudoscience.
Popper's attempted solution was to say that implicit in "brought to the attention of the senses" is a requirement that one's physical model generates falsifiable predictions of future observations. Thus astrology cannot be said to be part of a physicalist worldview, since horoscopes are so open to interpretation that they cannot be falsified.
That said, some notions of deities could be said to be physical, for example the proposition that there is a skygod who will make it rain if you say a certain prayer. This is not unphysical in this sense; it's just wrong. What would make it unphysical if you started moving the goalposts arbitrarily, for example "oh, it will cause rain next year instead" or "oh, you just weren't praying with true belief in your heart".
So, if someone created a falsifiable model of the soul that produced sensory interactions, would that mean the soul is physical?
In my mind this demonstrates 'physical' is not very well defined by physicalism, since souls etc. are considered to be non-physical, yet could in theory meet the requirements of physicalism.
Well, if someone produced such a model then they probably wouldn't be talking about the same soul as, say, the Christian soul.
Also the word "physical" has a different usage amongst philosophers than amongst laymen. In philosophy, a thought or idea might be thought of as physical since it is a property or pattern of neurological activity, but the average person would not say a thought was physical.
A brief Google suggests the term hasn't been used much since the 19th Century, but could mean either that everything is made of indivisible atoms, or that matter is made up of indivisible atoms. However, we've known for a long time that atoms are not indivisible.
Looking at your last link, perhaps you mean more that "everything is mass"? But quantum field theory as described in that article has been around since at least the 70s, and I think physicists and philosophers would still regard quantum field theory as a materialist theory. In modern usage, "materialism" is synonymous with "physicalism", i.e. that everything is physical [0]. Most physicists would call themselves materialists.
I ask because the same article was posted over a year ago and someone made a very similar looking comment [1].
[0] https://plato.stanford.edu/entries/physicalism/
[1] https://news.ycombinator.com/item?id=15727988