Suppose we have an infinite regress of turtles,
each supported by an earlier turtle, with no first turtle, and suppose that if
there is any last item, it’s not a turtle. In this case, the multiplicity of
the turtles explains why any given turtle is supported. But no multiplicity of
turtles fundamentally explains the supported turtles. Consequently, then,
something that is other than a multiplicity of turtles fundamentally explains
the supported turtles.
Those who know about the cosmological argument can probably see where I’m heading next.
Sceptics of Divine creation cleave to multiplicity of turtles with an earliest turtle hypothesis, where turtles here mean physical reality (of, being generous, however many universes). But Christians insist on the multiplicity of turtles with no earliest turtle as the cause of all turtles, because if turtles have an explanation, then their fundamental explanation cannot also be turtles, or even a first turtle.
A Type I multiplicity does not explain the turtles, because it does not explain any turtles earlier than the earliest turtle in the multiplicity. And a Type II multiplicity explains any turtle in the sequence as having an antecedent turtle cause, but not the cause of all turtles.
Applying this to real physics, because all physical causation is transitive, then all physical systems that exist must have a non-physical cause. Or in turtle language, anything non‑physical that explains the multiplicity of turtles explains all turtles (that is, all of physical reality) - because for any physical item, it is either a supported turtle or there is a supported turtle prior to it, and no regress can be explanatory as a whole.
That’s a simple way of stating why it has to be the case that a non‑physical entity explains all of physical reality.
