One hears echoes of Leibniz here, "the best of all possible worlds," the philosopher's defense against the presence of evil in the world, for which he was roundly mocked by Voltaire, especially in Candide. According to Leibniz, there was a possibility of other worlds that God had not actualized. God might have chosen a different world for us to inhabit. In other words, things could have been different. Indeed, God didn't have to create the world at all.
I just came across something that suggests that this idea was in the air already before Leibniz. In my research on the "natural sublime," I came across an article from 1951 by Ernest Tuveson (Modern Language Quarterly, vol. 12, pp. 20-38): "Space, Deity, and the 'Natural Sublime.'" Tuveson begins by discussing the reaction of poets and thinkers in the 17th century to the new conceptions of space and time that were being revealed by the "new universe." These conceptions upended the medieval view of the universe, one of limited size and harmonious in form: "about its center, our own planet, the heavenly bodies were arranged in beautiful concentric spheres, according to a scale of immutable values." All of this was shattered by the telescope, producing a terrifying universe, "one with no form, no center, above all, no plan perceptible to human reason." The next century, according to Tuveson, worked out an "imaginative symbolism" to assimilate the changes in philosophy, religion, and science. One of these symbolic forms was the natural sublime, imposing on nature conceptions of vastness and unlimited extent.
Tuveson then goes on to discuss one 17th-century thinker who was fascinated by the unlimited nature of space, Henry More. More was a philosopher of the Cambridge Platonist school, who was also a prolific author of verse and prose. Tuveson writes that More was "intoxicated" by the "sense of the unlimited expansion of the mind to comprehend all God's cosmic image" and quotes lines that remind me of the speculations of Bodmer and Breitinger:
To weet that long ago there Earths have been
Peopled with men and beasts before this Earth,
And after this shall others be again
And other beasts and other humane birth.
Which once admit, no strength that reason bear'th
Of this world's Date and Adams efformation,
Another Adam once received breath
And still another in endlesse repedation,
And this must perish once by finall conflagration.
That was stanza 76, by the way, of Democritus Platonissans (1648).