They're both aspects of this universe, and that despite they mutually annihilate. I used them as a metaphor for mutually incompatible theoretical aspects of the universe, and meant no more by it.

A difficult mental experiment for my part. Insofar as antimatter annihilates matter, I would translate such a term into that which is thought, that is, something intangible, and then come back to where I was. I think of "matter" in terms of objects, something objectless can hardly annihilate something object-like unless it in turn ignites the matter needed for it.