Uncaused Cause
That which is not itself caused — the first cause, or the ultimate brute fact, at which explanation stops because it cannot go further.
The reasoning is old and short. Everything we meet has a cause. If every cause in turn had a cause, the chain would never begin and nothing would be here. So either the chain is infinite in a way that explains nothing, or something at the root is uncaused. That something is what the argument calls the Uncaused Cause, or the First Cause.
In this system the Uncaused Cause is taken as synonymous with ØNE — Creator, God, Ultimate Reality, Supreme Being — understood as the Source and Sustainer of all that exists (Source · Creation · Emanation · Being).
And then the canon does something that decides how the whole Pillar can be read. It leaves the door open. For anyone unsure about a Creator or a Supreme Being, the Uncaused Cause may simply be understood as Ultimate Reality — the ultimate brute fact, the fundamental explanation that by definition cannot be reduced to anything simpler. The argument works either way, and the conclusion is not a religious claim before it is a philosophical one (Reality · Metaphysics · Ontology · Philosophy · The Ineffable).
That move is what allows the rest of this canon to be shared across traditions. A person is not being asked to convert in order to reason here; they are being asked to notice that explanation terminates somewhere, to call that terminus by whatever name is most meaningful and fulfilling to them, and to keep it in view while pursuing wisdom, truth, love, goodness and beauty (Navigating Towards Truth · Truth To ØNE, Errors To Us · Meta Unity of Meta Diversity · Essences, Renderings, And Ineffable Referents).
What must not be done with it is the thing traditions repeatedly do: take the name for the thing, and then defend the name (Do Not Concretize the Absolute · The Eternally Nameless · We Do Not Know).
Also called: the First Cause · Ultimate Reality · the ultimate brute fact
Stands on: ØNE · Reality · Being · Metaphysics
Opens onto: Source · Creation · Emanation · The Ineffable · The Eternally Nameless · Ontology · Theology · Cosmology · Pillar I — Sacred Ontology and Metaphysics
In play: the Story and the door — where a reader of any tradition or none is met without being asked to convert
Sources: Uncaused Cause (root page, stub — the classical argument, the identification with ØNE, and the open door for those unsure of a Creator) · ØNE, Source (root pages) · lionsberg.wiki: Uncaused Cause
Open: The page states the classical argument without engaging any of the standard objections to it; it is offered as a framework to consider rather than as a proof, and it should be read that way. · Whether ultimate brute fact and Creator are two readings of one thing or two different claims is left open on purpose, and that openness is itself load-bearing.