Parmenides, Empedocles, Anaxagoras and Early Atomists

Parmenides (540–472 BC)

Parmenides (540–472 BC). His thinking is seen in direct controversy with that of Heraclitus. He wrote a poem called On Nature, which proclaims the radical immutability of reality.

That is, according to Parmenides, changes are only sensory appearances; reason leads us to deny them.

The Pythagoreans already distrusted sensory input. Parmenides thought: If the senses tell us one thing and reason another, we must trust reason. The senses deceive us, whereas logic never cheats. Consequently, what I deduce rigorously by logic must be real.

Parmenides, in his poem, says a goddess has revealed an indisputable truth: "Being is, and non-being is not." Parmenides begins to draw logical consequences, and the most important is precisely the negation of the possibility of understanding change. He reaches a point where the confirmation of change is absurd; there is no possibility of rational understanding, as it is pure illusion.

Attempts at Conciliation: The Pluralists and Atomists

3.4 Attempts at conciliation: the pluralist

Empedocles, Anaxagoras, Leucippus and Democritus represent Greece's first attempt at conciliation. These thinkers sought to add perspective: Heraclitus accepted that physis is a process of constant change, and they also accepted Parmenides' principle that what is cannot come from what is not. These similarities in their thought group them as pluralistic.

Pluralism emerged as the position that reality does not arise from a single principle, but from a plurality of primitive elements, hence the name "pluralistic." Observable changes are combinations of primitive elements, not transformations of those elements.

Empedocles (494–432 BC)

Empedocles (494–432 BC). Friend of Parmenides. He set the famous theory of the four roots (water, air, fire and earth); these are the elements that underlie reality and are themselves unchanging. Natural things are combinations of these elements, governed by two forces:

• Love (which unites elements)
• Strife (which separates elements)

Anaxagoras (500–428 BC)

Anaxagoras (500–428 BC). He emigrated to Athens and pursued philosophy there. He was accused of impiety for claiming that the sun was not a god but a hot stone, and he went into exile. Anaxagoras held that not only the four classical elements exist, but many original particles or "seeds" as primitive types of things; everything contains a portion of many things. What predominates in a thing depends on the intervention of a mind (nous), a directing intellect.

Leucippus and Democritus (atomists)

Leucippus of Miletus (c. 450 BC?) and Democritus of Abdera (460–370 BC). They considered that basic reality is composed of a myriad of small hard objects: atoms, which move freely by chance. All things in the world are conglomerations of atoms. Reconfiguration and change are observed in these clusters of atoms, which is made possible by the vacuum (the space between atoms).