Presocratic Philosophy Review

Rejected human-like gods in Homer and Hesiod, criticizing their shameful behaviors.
Argued that if animals could draw, they'd make gods resembling themselves.
Envisioned god as 'mind' (nous), a cosmic, logical order, suggesting early monotheism.
Proposed earth and water as primary substances (arche).
Stated humans have limited knowledge and cannot fully understand god; belief is faith, not certainty.

A practical thinker, credited with navigation and calendar improvements.
No direct writings; ideas documented by later authors like Aristotle.
Anecdotes include inventing the gnomon, predicting a solar eclipse, profiting from olive presses, and falling into a well while stargazing.
Proposed water as the 'arché' (primary substance).
Believed the Earth floats on water, causing earthquakes.
Suggested a primordial swamp as the origin of life.
Identified solid, liquid, and gas as states of matter.
Theorized that all things possess a 'soul' (psyche) as the principle of movement.
Key contributions: sought unified explanations, relied on observation, moved away from divine causes.

Created one of the first world maps.
Introduced the 'apeiron' (indefinite/boundless) as the arché—a spatially unlimited, homogeneous material source of all opposites.
Believed qualitative opposites like hot/cold and wet/dry arise from the apeiron, with their interplay being 'justice' (e.g., seasons changing).
Noted the world's wet and dry states, suggesting air and water as primary elements, and a drying universe.
Proposed a cyclical universe: drying leads to deluge, then restart.
Envisioned a balanced cosmos with no beginning or end, and observed the sun is much larger than it appears.

Posited air as the 'arché,' essential for life and the human soul.
Explained transformation through air's condensation (clouds, water, earth) and rarefaction (fire).
Demonstrated with an experiment: warm air from relaxed lips, cold air from pursed lips, linking rarity to heat and density to cold.
Offered cosmogony based on condensation/rarefaction, explaining natural phenomena like earthquakes and lunar eclipses.

Known for his complex, aphoristic style.
Logos: A fundamental, understanding principle guiding the universe.
Union of Opposites: Every entity defined by its opposite; truth in tension (e.g., hot/cold).
Constant Flux: "You can never step into the same river twice," meaning everything is perpetually changing; stability is an illusion.
Fire as Arché: May have seen fire as the universe's fundamental principle, synonymous with life, driving cosmic cycles of destruction and creation. Linked soul's fate to its fiery essence and the logos.

School founded in Elea, used logical reasoning to dismiss speculation.
Parmenides of Elea (515?-460? BCE):
- 'Father of metaphysics,' central Presocratic philosopher.
- Authored "The Way of Truth" and "The Way of Appearance."
- Used deductive reasoning; asserted reality is a single, timeless entity (monism).
- Claimed change is impossible; existence is uniform, and apparent change is an illusion.
- Logic: only existing things can be thought; if change implies time (past/future), and only the present exists, then change is not real.
Zeno of Elea (died 425 B.C.E.):
- Disciple of Parmenides, created paradoxes to support his master's view against change and multiplicity.
- Achilles and the Tortoise: Fastest runner can never catch the tortoise due to infinite lead divisions.
- The Dichotomy: Motion requires infinite halfway points, making it impossible to start or reach a destination.
- The Arrow: An arrow at any instant occupies its own space, thus is at rest; motion is an illusion.

Left more writings than any other Presocratic.
First to propose four classical elements: earth, air, fire, and water.
Defined change, destruction, and generation as reconfigurations of these four elements.
Reconciled Parmenidean monism with pluralism: all is one (elements) and many (mixtures).
Identified two forces: Love (philia) combining elements and Strife (neikos) separating them, driving cosmic cycles.
Proposed a vision model where objects emit 'eidos' (tiny particles) that fit into the eye.

Proposed all entities are aggregates of different mixtures.
Started with an infinitely small, uniform substance; everything interconnected and derived from specific mixtures (e.g., bone has more "bone material").
Theorized infinite universes from this substrate, sharing governing laws.
Introduced 'mind' (nous) as the unifying element, orchestrating the mixing of substances to form the world.
His ideas resonate with modern quantum physics concepts (e.g., Heisenberg Uncertainty Principle).

Posited that everything comprises atoms and void.
Atoms are indivisible, constantly moving, and fundamentally unchangeable, forming a stable hidden reality.
Rejected infinite divisibility; atoms differ in size, shape, position, and arrangement.
Argued sensory perceptions are misleading; a fundamental reality exists beneath appearances.
Described a chaotic universe from random atomic assemblies, eliminating the need for gods or metaphysical entities.

Active 5th-4th centuries B.C.E., 'wise men,' itinerant intellectuals in Athens.
Taught rhetoric, language, culture, and persuasion; known mostly through critiques by Plato and Aristotle.
Key figures: Protagoras, Gorgias, Hippias.
Protagoras emphasized practical knowledge; held a relativist view of truth ("man is the measure of all things").
Relativism led to negative views, often seen as arguing for money.
Socrates challenged Sophistic relativism in ethics and virtue.
Redirected philosophy to practical reasoning, kickstarting ethical philosophy with "How ought we to live?"