mikkel_the_dane
My own religion
What would prevent a thing that exists as itself from interacting with anything else? If you mean the universe can't interact with us, we are as much a part of the universe as anything else. We are part of it, and interact with it. If there is something else out there that is not what we call the universe, it could interact with that too.
'In itself' does not mean incapable of being or becoming something that extends beyond how that thing is defined at any given time. A river has a certain definition of being in itself a river, as in a constant flow of water. That the water contained in the idea of river constantly changes doesn't prevent it from being a river.
Then there is no universe in itself.