The Principle of Contingent Causation: The Impossibility of Infinite Regress.

[Neo-Scholastic]

I'm not sure what people mean by "the totality" here, or what it means to say that the universe itself may suffice as a necessary cause.

Speaking only for myself, capitol-T Totality refers to some kind of Plotinus/neo-Platonic One or “the All”. While not a cause proper, the idea is of the all-encompassing wholeness of everything that exists. The Totality is akin to Anselm’s being the greater than which cannot be conceived. And the pantheism comes from Swedenborg’s visionary insight that God did not create ex nihilo; buth rather our of Himself, which to my mind implies an act of kenosis.

Obviously, when we total up all the stuff that's out there -- all the stuff that makes up the universe -- nearly all of it is clearly contingent….

The physical universe for certain IMHO but of course opinions vary about the reality of other categories of being such qualities, universals, and mathematical objects…and that’s not to mention (I guess I am) meaning and/or intentionality as a real part of the cosmos that cannot be hand-waved away or taken for granted.

So we can't just say that "the universe" is non-contingent. We have to point to one aspect or level of the universe that is necessary in order to give rise to all the contingent things….And then I think we're back at the beginning, asking what part of everything there is is necessary for the rest of it.

Not a part. I think that is the mistake being made. Perhaps there is a distinct but inalienable quality common to all beings but rather than looking down to find a particular common quality that we look “up” to see what degree a particular being partakes of the nature of the whole….which IMHO can only be known by what it is not (the Negative Way).