The Orthosphere hosts a philosophical argument that
skips an important step.
We theists recognize two general categories of causation: mechanistic (i.e., “cause-and-effect”) and agency (“ground-and-consequent”). Most people, including most God-deniers, will initially agree that these two categories are real, and distinct, and unbridgeable … until they see where the argument is going.
From recognition of the unbridgeable distinction between mechanism and agency, I argue that agency cannot “arise” from mechanism – this is what the God-deniers who haven’t denied agency from the start will then deny and this denial can then be shown absurd and thus false – and thus that agency is, and must be, fundamental to [the] nature of reality.
The important step is the proof that agency cannot arise from mechanism (as he puts it); it is not obvious that this is true, and the fact that people might 'initially agree' to it doesn't establish it as more than an unchallenged assumption.
(By the way this frame is older than monotheism in the West: Aristotle explains causality in just this way in the second book of the Physics.)
Consider that, as far as we can tell, atoms have no agency. An atom of carbon or of hydrogen or oxygen seems to decide on nothing; it joins into bonds, such as hydrogen and oxygen forming water, for purely chemical and physical reasons. This is 'mechanistic' determination on the Orthosphere's model.
Yet water has properties that its components, hydrogen and oxygen, did not. Both of these are gaseous at room temperature, for example; water is liquid at the same range of temperatures. Water has the property of 'wetness,' then, which has somehow arisen from the bond between the things that both lack that property. We can say some things about how and why this happens, but that it happens is clear enough. New properties emerge from combinations that happen mechanistically.
Why, then, should not agency be a property that emerges from things that happen mechanistically? Other properties, even complex ones, seem to do this. The carbon joins into long protein chains, the water is joined with it, and (skipping a long discussion) eventually you have DNA. This has a new property -- the capacity to order things it encounters mechanistically into a design that is not random but follows a kind of 'intention.' This ability to take from the world and put things into the order that is also 'you' is called life (as explained by philosopher Hans Jonas).
If this kind of proto-intention can arise from what appear to be mechanistic actions, why not a real intention? Why shouldn't it be true that living beings of certain kinds have the property of agency, even though none of their components had it before they were joined and ordered into that form?
This is, by the way, a good reason to reject materialism: it is not merely the material that matters. All the same material -- all the same atoms of oxygen and hydrogen and carbon, etc -- if not ordered in this way lack the properties of life and agency. These only seem to arise when the right order is brought to them. Thus, the form -- which is not material, but the way in which the material is ordered -- exists and is causally important, and not only the material. Reality is not materialistic but hylomorphic as the ancients said.
This is not an anti-theistic argument or a theistic one; you can make both arguments from this ground. Perhaps a God is then unnecessary, and being unnecessary should be excluded according to Occam's Razor. Yet what explanation is there for reality having this strange quality, such that thinking agents can and do apparently automatically arise from deterministic material processes? Why should reason and decision be inherent in a material that does not need them, existing whether or not agents do? Occam's Razor is only a tool for gamblers, not a proof; and here it seems clear that unnecessary things do exist, because we experience being one of those things all the time.
Perhaps, then, reality has this order because the order was wanted; and if it was wanted, there must have been someone who wanted it. Someone who had the power to set this basic structure of reality, either through design or through will, or possibly merely through longing.