Combinations. Attempts were made by the ancient Greeks to save the evidence of the senses and counter the total denial of change. In the 400s, the so-called Pluralists, Empedocles and Anaxagoras, accepted Parmenides' claim that reality is indeed forever changeless, but then went on to assert that it is also fundamentally plural. The universe is a composite of basic, indivisible substances that each enjoy the characteristics of the Eleatic "what is"—namely, each is eternal and unchanging. Since there are many such permanent and timeless entities, however, the world of the senses can be constructed by bringing them together into different combinations.

Basic Elements. For Empedocles, the "roots" (rhizomata) of reality are the elements earth, air, fire, and water. They are original substances in the sense that they are uncreated and everlasting, just as Parmenides had demanded reality should be...