Full Idea
It is in the highest degree unlikely that this earth and sky is the only one to have been created.
Gist of Idea
This earth is very unlikely to be the only one created
Source
Lucretius (On the Nature of the Universe [c.60 BCE], II.1057)
Book Reference
Lucretius: 'On the Nature of the Universe', ed/tr. Latham,Ronald [Penguin 1951], p.91
A Reaction
I can only admire the science fiction imagination of this, which roughly agrees with the assessment of modern cosmologists. We think imagination was cramped in the ancient world, and now wanders free - but that is not so.