Introduction
Ancient Greek philosophy laid the foundation for Western philosophical thought and scientific inquiry from roughly the 6th century BCE to the end of antiquity. These thinkers revolutionized how humans understand the world by shifting from mythological explanations to rational inquiry, creating systematic methods to investigate reality, knowledge, ethics, and politics that continue to influence modern thought.
Pre-Socratic Philosophers (6th-5th Century BCE)
Philosopher | Time Period | Key Contributions | Notable Works/Concepts |
---|---|---|---|
Thales | c.624-546 BCE | • First to seek natural (not mythological) explanations<br>• Proposed water as the fundamental substance<br>• Predicted a solar eclipse in 585 BCE | • “All things are full of gods”<br>• Early cosmology<br>• Founded Milesian School |
Anaximander | c.610-546 BCE | • Proposed the concept of “apeiron” (the boundless)<br>• Early evolutionary ideas<br>• First known cosmological model | • Created first known map of the world<br>• Concept of natural justice and balance |
Pythagoras | c.570-495 BCE | • Founded mathematical philosophy<br>• Established religious/philosophical community<br>• Pythagorean theorem | • “All is number”<br>• Mathematical harmony of cosmos<br>• Transmigration of souls |
Heraclitus | c.535-475 BCE | • Philosophy of change (“panta rhei”)<br>• Concept of logos (universal reason)<br>• Unity of opposites | • “You cannot step in the same river twice”<br>• Fire as primary element |
Parmenides | c.515-450 BCE | • Philosophy of unchanging being<br>• Logic-based metaphysics<br>• Distinction between appearance and reality | • “What is, is; what is not, is not”<br>• Rejection of change as illusion |
Democritus | c.460-370 BCE | • Atomic theory of the universe<br>• Materialist explanation of reality<br>• Ethical theory of happiness (euthymia) | • Atoms and void as fundamental reality<br>• Mechanical universe without divine intervention |
Classical Period (5th-4th Century BCE)
Socrates (c.470-399 BCE)
- Method: Socratic method (dialectic questioning)
- Focus: Ethics, virtue, knowledge
- Key Concepts:
- “Know thyself”
- Virtue is knowledge
- Examined life is the only one worth living
- Claimed to “know that he did not know” (Socratic wisdom)
- Legacy:
- Executed for “corrupting youth” and “impiety”
- Known primarily through writings of others (Plato, Xenophon)
- Shifted philosophy’s focus from natural world to human affairs
Plato (c.428-348 BCE)
- School: Founded the Academy
- Key Works: The Republic, Symposium, Phaedo, Apology
- Core Philosophical System:
- Theory of Forms: True reality consists of perfect, eternal Forms; physical world is imperfect shadow
- Epistemology: Knowledge is recollection of Forms the soul knew before birth
- Psychology: Tripartite soul (reason, spirit, appetite)
- Political Theory: Ideal state ruled by philosopher-kings
- Famous Allegories:
- Cave (perception vs. reality)
- Divided Line (levels of knowledge)
- Chariot (soul’s components)
Aristotle (384-322 BCE)
- School: Founded the Lyceum (Peripatetic School)
- Key Works: Nicomachean Ethics, Politics, Metaphysics, Poetics
- Core Philosophical System:
- Metaphysics: Form and matter; four causes (material, formal, efficient, final)
- Logic: Syllogistic reasoning, categories, first systematic logic
- Ethics: Virtue as golden mean between extremes; eudaimonia (flourishing) as goal
- Politics: Humans as “political animals”; analysis of constitutions
- Science: Systematic classification and empirical observation
- Legacy: Most influential in medieval thought, science, and logic
Hellenistic Schools (3rd Century BCE-3rd Century CE)
School | Key Figures | Central Teachings | Practical Applications |
---|---|---|---|
Epicureanism | Epicurus<br>(341-270 BCE) | • Atomic materialism<br>• Pleasure (absence of pain) as highest good<br>• Gods exist but don’t interact with world | • Moderation in desires<br>• Friendship and community<br>• Overcome fear of death |
Stoicism | Zeno of Citium<br>(334-262 BCE)<br>Seneca<br>Epictetus<br>Marcus Aurelius | • Living according to nature/reason<br>• Virtue as only true good<br>• Cosmic determinism<br>• Control only what you can control | • Emotional self-regulation<br>• Acceptance of fate<br>• Cosmopolitan ethics<br>• Discipline of judgment |
Skepticism | Pyrrho<br>(c.360-270 BCE)<br>Sextus Empiricus | • Suspension of judgment (epoché)<br>• Critique of dogmatic claims<br>• No certain knowledge possible | • Freedom from dogmatism<br>• Mental tranquility (ataraxia)<br>• Examining all sides of arguments |
Cynicism | Diogenes of Sinope<br>(c.412-323 BCE) | • Rejection of social conventions<br>• Natural life as virtuous life<br>• Self-sufficiency (autarkeia) | • Minimalist lifestyle<br>• Social criticism<br>• Freedom from possessions |
Neoplatonism | Plotinus<br>(204-270 CE)<br>Proclus | • Hierarchy of reality emanating from the One<br>• Soul’s ascent to divine unity<br>• Mystical experience | • Meditative practices<br>• Influence on early Christianity<br>• Synthesis of earlier philosophies |
Key Philosophical Concepts & Comparisons
Theories of Knowledge
- Plato: Knowledge is recollection of eternal Forms; reason over senses
- Aristotle: Knowledge through empirical observation and logical analysis
- Skeptics: Certain knowledge impossible; suspend judgment
- Epicureans: Knowledge through sense perception; atoms and void
Ethical Theories
- Socrates/Plato: Virtue is knowledge; ignorance causes wrongdoing
- Aristotle: Virtue as golden mean; practical wisdom (phronesis)
- Stoics: Virtue as only good; indifference to externals
- Epicureans: Pleasure (absence of pain) as goal; prudent calculation
Conceptions of Reality
- Parmenides: Unchanging, unified Being as true reality
- Heraclitus: Constant flux; unity in change
- Plato: Transcendent Forms vs. physical appearances
- Aristotle: Form and matter united; teleological universe
- Atomists: Material atoms in void as fundamental reality
Common Philosophical Problems & Solutions
The Problem of Change
- Heraclitus: All is flux; stability found in the pattern of change
- Parmenides: Change is illusion; true reality is unchanging
- Aristotle: Potentiality becoming actuality; change as natural process
The Body-Soul Relationship
- Plato: Soul trapped in body; liberation through philosophy
- Aristotle: Soul as form of the body; unity of substance
- Epicureans: Both are material; soul disperses at death
- Stoics: Soul as fragment of divine fire/reason
The Good Life
- Socrates: Self-knowledge and virtue
- Plato: Harmony of soul; contemplation of Forms
- Aristotle: Virtuous activity according to reason; moderation
- Epicureans: Ataraxia (tranquility) through moderate pleasure
- Stoics: Living according to nature/reason; accepting fate
Philosophical Methods & Approaches
Dialectic (Socratic/Platonic)
- Start with common opinions or definitions
- Question and refine through critical examination
- Expose contradictions and refine understanding
- Goal: Move toward truth through dialogue
Aristotelian Analysis
- Systematic categorization
- Empirical observation
- Logical syllogisms
- Identification of causes
Hellenistic Practical Philosophy
- Focus on achieving tranquility (ataraxia)
- Spiritual exercises and daily practices
- Application to everyday life challenges
- Community of philosophical practitioners
Legacy & Influence
Mathematics & Science
- Pythagorean mathematical discoveries
- Aristotelian systematic classification
- Atomist theories anticipating modern physics
- Logical methods of inquiry
Political Theory
- Plato’s Republic (ideal state)
- Aristotle’s analysis of constitutions
- Stoic cosmopolitanism
- Cynics’ critique of social conventions
Modern Philosophy
- Renaissance revival of Platonism
- Aristotelian influence on medieval scholasticism
- Stoic influence on cognitive psychology
- Skeptical methods in epistemology
Resources for Further Study
Primary Texts
- Plato’s Dialogues (especially Republic, Symposium, Apology)
- Aristotle’s works (Nicomachean Ethics, Metaphysics, Politics)
- Epictetus’ Enchiridion (Stoicism)
- Diogenes Laertius’ Lives of Eminent Philosophers
Modern Introductions
- “A History of Western Philosophy” – Bertrand Russell
- “The Greeks and the Irrational” – E.R. Dodds
- “Ancient Philosophy: A New History” – Julia Annas
- “Aristotle’s Way” – Edith Hall
Online Resources
- Stanford Encyclopedia of Philosophy (plato.stanford.edu)
- Internet Encyclopedia of Philosophy (iep.utm.edu)
- Perseus Digital Library (ancient texts with translations)
- In Our Time podcast (BBC) episodes on ancient philosophers