The horizon cannot be comprised within the horizon … The ultimate measure cannot be measured; the boundary which delimits all things cannot itself be bounded by a still more distant limit …
Kilby, Karen (2005-04-19). The SPCK Introduction to Karl Rahner (SPCK Introductions) (Kindle Locations 356-358). SPCK. Kindle Edition.
The most fundamental issue with cosmology is that it uses a “barred” or “disavowed” transcendentalism that collapses into an impossible idealism. The posited observer always implicitly ‘looks at’ reality as a whole without being part of it. The ontological meaning of the transcendental is not that we somehow see beyond or from beyond the horizon, but that we cannot see except insofar as we recognize the horizon, and that we are always bounded within it. The place of the
One in later metaphysics (and its over-determination precisely in the metaphysics that founds modern science’s certainty on the mathematical) is barred but still necessary. It can be replaced by the singularity, by some sort of pantheistic understanding of reality, or anything else, but structurally it has to be there or the models of cosmology fall apart. Were cosmologists honest (firstly with themselves) they would need to use some term for the One, however that would bring the paradox at its base too close for comfort.
Another way of putting it … metaphysical cosmology thinks the different as different from the other, but it doesn’t think difference as such. In not doing so, neither its measuring apparatus (itself) nor what is to be measured (the other) are distinct and neither is determined, in which case neither can be determined, since an a priori determination of one is necessary in order to determine the other.