Berdyaev and Lenau.
Recently I discussed "Two Ways" that are mentioned in Poul Anderson's fiction. They are also mentioned in his non-fiction, i.e., in the article "Wellsprings of Dream" on pp. 237-247 of All One Universe (New York, 1997). The ultimate state of the universe might all be in one mind. I need to reread this article and maybe also the story, to continue rereading Operation Chaos and, when it arrives, to start reading SM Stirling's Against The Tide Of Years.
The human imagination encompasses this entire universe and every conceivable universe.