The world, and whatever that be which we call the heavens, by the
vault of which all things are enclosed, we must conceive to be a deity,
to be eternal, without bounds, neither created nor subject at any
time to destruction. To inquire what is beyond it is no concern of
man; nor can the human mind form any conjecture concerning it.
-- Pliny the Elder (23-79 AD)
-- Natural History, Book ii, Sect. 1