Archaic Ionian and Doric philosophical thought clearly laid the foundations of European philosophy. With the passage to the classical period, the Greek philosophers pondered the pre-existing opposing conceptions and formulated their own. Through their theories, then, they tried to logically marry the "immovable" of the Ionians with the "unchanging" of the Dorian philosophers.
Thus the classical era begins with two important Greek Combinatorial philosophers, Empedocles (494-434 BC) and Anaxagoras (500-428 BC).
Empedocles, therefore, taught that the universe is composed and decomposed by four unchanging "rhizomes": water, earth, air and fire. In his view, each genesis and decay is caused by mixing the four aforementioned "rhizomes" in different proportions for each morphology. This view was later accepted by the Atomic philosophers. In addition, Empedocles described the universe as immovable in its entirety according to the Eleatic model but as moving in its parts according to the Heraclitean model.
Anaxagoras' interests were a little different. He was the first to raise the issue of nutrition. He sought to explain how from the food we put in the mouth, things are formed that did not exist before, that is, flesh from non-flesh, bones from non-bones, etc. He finally came to the conclusion that matter is composed of molecules of all kinds, forms, shape, size and number. He also argued that in every physical body there are molecules of all kinds. For example, water and bread contain elements of the same nature as our body, so there are no simple elements, "rhizomes" (water, air, earth, fire). In addition, according to Anaxagoras, the amount of matter remains constant. Finally, Anaxagoras considered the Mind as a driving force for the processes of genesis, which for him was a substance completely different from the components of matter. Thus he continued the notions of the division of the concept of substance into matter and energy.
