Full Idea
Empedocles holds that the corporeal elements are four, but that all the elements, including those which create motion, are six in number.
Gist of Idea
Empedocles said that there are four material elements, and two further creative elements
Source
report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314a16
Book Reference
Aristotle: 'Sophistical Refutations, On the Cosmos etc (III)', ed/tr. Forster,E.S. /Furley,D.J. [Harvard Loeb 1955], p.165