if speaking in terms of Principal Ideals is inconsistent, we could always press the cosmological background-cone into service.
Consider the interval between, eg cosmology, and any other concept: we can classify these intervals according to the following schema:
consequential: one background cone contains the other.
inconsequential: the background cones fail to intersect, or do so only partially.
tangential: one concept occurs on the boundary of the other's background cone.
I hope a trichotomous classification of intervals is consequential with regard to cosmology? :-)