These are philosophical vignettes signifying a stance on the meaning of such abstraction as time and space, Kant and Ouspensky put it this way: There are two “facts”: there is an “us” and there is a “not us.” Time is an ordering device of the human mind, and does not exist in any other place. Someone once said “We have a past and a future, but we don’t live there.” Eastern philosophers, such as Hermes Trismegestus in The Kybalion, find a duality in everything (some pedestrian examples are heat and cold, light and dark, etc.) Blake is making that same point by personifying Eternity and Time like they could be “in love”—a poetic statement of the paradox. Eternity is an entirely human concept; it doesn’t exist except in the construction of human thinking. Joseph Campbell’s main point in spending his life examining myths from dozens of cultures is that the human mind, no matter where it resides, by its nature builds essentially the same set of symbols—God, son of God, heaven and hell, etc.—to “make sense”, to “give meaning” to our material existence. Science is a good example of the effort to make the physical universe follow “laws”, but the philosopher sees those “laws” as Man’s invention, not as “facts” in and of themselves.