Empedocles

None of Empedocle's work has survived in tact. We have only a few fragments and quotations made by other early philosophic writers of his work in commentaries.

It is Simplicius [flourished 500-540 AD] who gives us the most.

Simplicius writes, (and then quotes Empedocles);

"Empedocles also hints at a double world: 'For they are all in union with their own parts - Sun and Earth and Heaven and Sea - which have been separated from them and grown into mortal things' ..."
[Simplicius, 'Physics']

This suggestion of a 'double-world' is also found in mysticism;

"It is said of the philosopher and thaumaturge Empedocles that he claimed the existence of two suns".
[Alchemy and Mysticism, A. Roob, Taschen page 25]

Of course, the Presocratics are important in terms of their SUGGESTIVENESS - cf., Heraclitus.