Consider Democritus' idea of the atomos. It is made of "a" meaning negation and "tomos" meaning a cutting ("Atom"). It means something you can't cut. It sounds eerily similar to the Sanskrit word atma (Soul in English). The Bhagavad Gita describes the soul in chapter 2, verses 23-25 -
Never can a weapon chop/divide/cut it into pieces, nor can fire burn it. Never can water wet it, nor can wind dry it. Everlasting, all-pervading, immutable, the soul is eternal.
In addition to sounding similar, the atma may be what Democritus was looking for. Perhaps, he unjustly limited himself to the physical realm. Eventually, something was found and named atom, but it really wasn't the atom idealistically. It was divided further into neutrons, protons, and electrons.
Chances are we may not ever find the atom by dividing things. There's something tomic about anything you can predicate a physical size of. The moment you propose that the atom has a size of x, you imply the possibility of x/2, x/3, and so on. Nothing stops a real magnitude from getting infinitely divided (Berryman sec. 6). Thus, the atom may not have any physical attributes. Perhaps, it doesn't belong to the physical realm but only manifested in it, just like loyalty is manifested in the dog. Perhaps, it may be something we can't know because most of what we call knowledge is predicates (of whatever we claim to know). Perhaps, that is the nature of the soul, if it is. Or this, too, is simply a predicate?
I stumbled on a book called "Kundalini -Tantra Rahsya" by Prem Kumar Sharma. He says that modern people confuse atma with jivatma. Jivatma means soul. Atma he says is even more subtle and pure than jivatma. It is indivisible and omnipresent. It has no features, no qualities (10,12).
"Atom".Online Etymology Dictionary. Douglas Haper, 2020. Etymonline.com. Accessed 5 August
Berryman, Sylvia, "Democritus", The Stanford Encyclopedia of Philosophy (Winter 2016 Edition),
Edward N. Zalta (ed.), URL = <plato.stanford.edu/archives/win2016/entries/democritus/>.
Accessed August 5, 2020.
Bhagavad Gita - The Song of God, commentary by Swami Mukundananda, Swami Mukundananda
2014, holy-bhagavad-gita.org. Accessed 5 August 2010.
Sharma, Prem. Kundlini-Tantra Rahsya. Dheeraj Poket Books.