The long-standing puzzle regarding the relation between Anaxagoras' pluralism and Parmenides' monism can be met and solved on its own terms. We need not deny that Parmenides was a numerical Monist and we need not suppose that Anaxagoras failed to adequately consider Parmenides' basic principles. Anaxagoras did not attack these basic principles, because he thought that they were compatible with pluralism. He not only provided a brilliant explanation of the emergence of our world within the Chaos, but he posited a fascinating cosmology of worlds within worlds within the One. And since his Chaos is Parmenides' One under an alternative description, Anaxagoras postulated a Parmenidean cosmology: he postulated a cosmology of worlds within worlds within the One.
Sisko, John E., "Worlds within World within the One: Anaxagoras' Parmenidean Cosmology" (2000). The Society for Ancient Greek Philosophy Newsletter. 390.