I am reading History of Western philosophy by Bertrand Russell and, when talking about the Atomists, he says:
he [Leucippus] conceded the monists that there could be no motion without a void.
And then, the position of Parmenides:
you say there is the void; therefore the void is not nothing, therefore is not the void.
As far as I know the monists believed in the void (that is on the first quote). Parmenides was a monist. So, does he argues against the void? Maybe in place of "Parmenides" there should be "Empedocles", but am not sure...