I think there is an elephant in the room too! But I'll tell you what I think the elephant is. Capital M-Meaning, or Ultimate Meaning (UM). (By Ultimate Meaning I mean, heh, meaning that is not subjective but objective.)
Physical Substance Monists tend to believe in a deterministic universe devoid of Ultimate Meaning.
I sense that the three of you -
@smcder,
@Constance,
@Tyger - strongly disagree with that concept. You all three seem to believe that there is Ultimate Meaning, particularly for humans.
This UM seems to be related to a supposed non-physical, spiritual realm. A realm filled with souls, God, gods, demons, and angels. These beings are interested in us. We - our souls, spirits, and/or minds - may even "belong" to this realm. A realm where there is Ultimate Meaning.
My own view is that while such a realm might exist, it won't have Ultimate Meaning, just lower case m-meaning.
There may be "spiritual" beings that exist and interact with us, but 1) they gotta be made of something and if they can interact with us, it's gotta be something related to the stuff we're made of, 2) while what these beings have in mind for us may be Ultimate to us, it wouldn't be Ultimate to them. Meaning, if we have a backstory, they too must have a backstory. That is, if we having UM via these entities, then from their POV it is subjective meaning.
It's the old argument: if God created us, who created Him?
If there is a spiritual realm that created us in the physical realm, who created them in the spiritual realm?
Finally, while I'm not as big a proponent of Langan as it may seem, haha, he is apparently a Substance Monist who very strongly believes in a reality suffused with Ultimate Meaning. Thus Substance Monism does not preclude there being UM.