People have been talking about multiverses as a philosophical idea for a long time. But the current incarnations in physics, I think, are more indicative of problems with some things going on at the frontier of physics than ideas that are gonna last.
If, like Hume, I had all manner of adornment in my power, I would still have reservations about using them. It is true that some readers will be scared off by dryness. But isn't it necessary to scare off some if in their case the matter would end up in bad hands?
A philosophical attempt to work out a universal history according to a natural plan directed to achieving the civic union of the human race must be regarded as possible and, indeed, as contributing to this end of Nature.
All literature, all philosophical treatises, all the voices of antiquity are full of examples for imitation, which would all lie unseen in darkness without the light of literature.