Motion and Vacuum
"How can motion be reconciled with a single, universal substance?
"Parmenides (~480 BC) motion is an illusion; there is no vacuum
"Zeno (~445 BC) motion is absurd
"Empedocles (~445 BC) four elements
Earth, water, air, fire
"Anaxagoras (~445 BC) infinite number of elements
"Atomists atoms and vacuum