When we trade in Universals or concepts of substantive reality, we are engaging concepts of notionally “whole” or “complete” systems. The curious thing about any “totality” or aspirationally “complete” system is that there is no outside to that entity, no external conditions or properties. Everything is internal to that system.
Why does this matter? Because this is a globally distributed ontological (and existential) property of all dynamical (and living, or thinking) complex systems. In language: all definitions are made in terms of other definitions – circularly self-referential, without external anchor. In mathematics: the hyper-inflating, indefinitely-extensible and functionally self-propagating complexity of a vast and intricate tautology stares straight back at us. We find ourselves perennially returning to the downstream consequences of the kernel of ontological differentiation between something and nothing, a thing and a no-thing; a difference which (incidentally) also defines information.
Most interesting of all: the impossibility of certain knowledge concerning external worlds is mirrored in and as an endlessly hyper-inflating vacuum of introspection. Like the Tardis, it surprises us by always being “bigger on the inside”.