Pre-Socratics

Milesians:
Thales (624-546 BCE)
Anaxaminder (610-546 BCE)
Anaximenes (585-528 BCE)

Themes

• Look to the natural world
• Sought to understand fundamental nature of the universe (originating "stuff")
• Science and philosophy intertwined
• Soul makes things alive and gives them motion

Pythagoreans:
Pythagoras (571-490 BCE)

Themes

• Look to the natural world
• Sought to understand fundamental nature of the universe (originating "stuff")
• Science and philosophy intertwined
• Ethical code

Transition to Eleatics:
Xenophanes (570-478 BCE)
Heraclitus (535-475 BCE)

Themes

• Milesian exploration of the natural world
• Exploration of human nature
• Question limits human understanding

Xenophanes

• Fragments Lines 5-6: criticized anthropomorphizing the gods
• Fragments Lines 8-10: cycle of elements
• Fragments Lines 19-20: criticizes emphasis on strength as quality of rulers

Heraclitus

• Fragments 1, 2, 19, 47, 91: universe ordered by reason
• Fragments 3, 5, 6, 92, 93, 94: humans fail to understand the truth
• Fragments 8, 10, 11, 51: seeking the truth is hard work and may not be rewarding
• Fragments 14, 16, 17, 18: Beware what others claim as truth

Heraclitus

• Fragments 23, 24, 25, 29, 36: proportion, balance (moira)
• Fragments 30, 32, 39, 40, 41, 42, 45, 47, 52, 56, 57, 59, 67, 69, 70, 81: change/opposition (but within a unity and according to an order, compare Parmenides)

Eleatics:
Parmenides (late 6th-early 5th cent. BCE)
Zeno (490-430 BCE)
Melissus (of Samos) (late 5th cent. BCE)

Themes

• Fragments Lines 10, 38-52, 73-75: Nature of "not-being" / nothingness (compare to Heraclitus' opposition)
• Fragments Lines 60-70, 75-89, 95-108: nature of being is unchangeable, eternal, unmoving

Themes

• Fragments Lines 30, 45-50: Human perceptions are illusions (compare to Socrates, Heraclitus)
• Fragments Lines 38-52: How to evaluate claims of what is (epistemology)

Pluralists & Atomists
Anaxagoras (500-428 BCE)
Empedocles (495-430 BCE)
Democritus (460-370 BCE)
Leucippus (d. 370 BCE)

Pluralist Themes

• Maintain Parmenides' structure of being/not-being with an irreducible pluralism

Pluralist Themes

• Anaxagoras: External, intelligent force organizing the universe
• Empedocles: cycle of love and strife of the four elements (compare to Milesians, Heraclitus)

Atomist Themes

• Substance and void (being and not-being) (compare Milesians, contrast Parmenides)
• Appearance vs reality (compare Heraclitus, Parmenides, Socrates)
• Senses combined with reason lead to truth (compare Pythagoreans, Heraclitus, Parmenides)

Sophists

Who?

• Hippias (d. 490 BCE) Protagoras (485-415 BCE)
• Hippias (d. 490 BCE)
• Gorgias (485-380 BCE)
• Prodicus (465-395 BCE)

Who?

• Antiphon (d. 411 BCE) Prodicus (465-395 BCE)
• Thrasymachus (459-400 BCE)
• Critias (460-403 BCE)
• Anisthenes (445-365 BCE)

Themes

• Practical methods of how to live, break from accepted view of rationalism
• Teachers, orators for hire
• Denigrated by Socrates, Plato, and Aristotle