Aristotle (384-322 BCE) was one of the most influential philosophers in Western history, whose work shaped virtually every field of knowledge for centuries.

## Life and Background

**Early Life**: Born in Stagira, Macedonia, his father Nicomachus was court physician to King Amyntas III. This connection to Macedonian royalty would prove significant throughout his life.

**Education**: At 17, he joined Plato's Academy in Athens, where he studied for 20 years until Plato's death in 347 BCE. Despite being Plato's most brilliant student, he wasn't chosen to lead the Academy.

**Tutoring Alexander**: From 343-336 BCE, he tutored young Alexander (later "the Great"), potentially influencing one of history's most significant conquerors.

**The Lyceum**: In 335 BCE, Aristotle founded his own school in Athens, the Lyceum, where he taught while walking (hence his followers were called "Peripatetics"). The school included extensive collections of manuscripts and specimens.

## Major Philosophical Contributions

### Metaphysics
- Developed the concept of **substance** (ousia) and the theory of **four causes** (material, formal, efficient, and final)
- Distinguished between potentiality and actuality
- Argued for the "Prime Mover" - an unchanging first cause of all motion
- Rejected Plato's Theory of Forms, arguing instead that universals exist within particular things

### Logic
- Created the first formal system of logic
- Developed the **syllogism** (deductive reasoning from premises to conclusion)
- His "Organon" (tool) became the standard logic textbook for over 2,000 years
- Established principles like the Law of Non-Contradiction

### Ethics
- Promoted **virtue ethics** based on character rather than rules or consequences
- Developed the concept of the "Golden Mean" - virtue as balance between extremes
- Argued that **eudaimonia** (flourishing/well-being) is the highest human good
- Distinguished between intellectual and moral virtues

### Politics
- Classified governments into six types (three good, three corrupt)
- Viewed humans as inherently political animals ("zoon politikon")
- Defended slavery and excluded women from political life (reflecting his era's prejudices)
- Favored a "polity" - a constitutional government mixing democracy and oligarchy

### Natural Science
- Made extensive observations in biology, especially marine life
- Classified animals and developed early taxonomic systems
- His biological works were remarkably accurate, though his physics was later disproven
- Incorrectly believed in spontaneous generation and a geocentric universe

### Psychology
- Wrote "De Anima" (On the Soul), exploring the nature of life and consciousness
- Identified three types of souls: vegetative, sensitive, and rational
- Viewed the soul as the "form" of the body, not separate from it

### Aesthetics
- In "Poetics," analyzed tragedy and epic poetry
- Introduced concepts like catharsis (emotional purging through art)
- Developed the three unities of drama (action, time, place)
- Argued art imitates life (mimesis) but can represent universals

## Major Works

Key surviving texts include:
- **Nicomachean Ethics** - moral philosophy
- **Politics** - political theory
- **Metaphysics** - first philosophy
- **Poetics** - literary criticism
- **Physics** - natural philosophy
- **De Anima** - psychology
- **Organon** - logical works

Many works are lecture notes rather than polished texts. An estimated two-thirds of his writings are lost.

## Historical Impact

### Ancient Period
- His immediate successors (like Theophrastus) continued his empirical approach
- The Lyceum remained active for centuries
- His works were preserved by Islamic scholars during the Middle Ages

### Medieval Period
- Thomas Aquinas synthesized Aristotelian philosophy with Christianity
- Became "The Philosopher" in medieval universities
- His logic and metaphysics dominated scholastic thought
- Islamic philosophers like Ibn Rushd (Averroes) wrote extensive commentaries

### Scientific Revolution
- Galileo and others challenged his physics
- Francis Bacon critiqued his method while developing empiricism
- His biological observations remained valuable even as his physics was overturned

### Modern Influence
- Virtue ethics has seen renewed interest since the 1950s
- His logic remained standard until the 19th century
- Influenced fields from literary criticism to political science
- His emphasis on empirical observation helped establish the scientific method

## Key Concepts and Terminology

- **Hylomorphism**: Theory that substances are composed of matter and form
- **Teleology**: The study of purposes or final causes in nature
- **Entelechy**: The realization of potential
- **Phronesis**: Practical wisdom
- **Akrasia**: Weakness of will

## Limitations and Criticisms

- Supported slavery and held sexist views typical of his time
- His physics was fundamentally incorrect about motion and cosmology
- Sometimes reasoned from insufficient empirical data
- His teleological approach to nature is rejected by modern science

Aristotle's comprehensive approach to knowledge, systematic methodology, and influence on virtually every academic discipline make him one of history's most important thinkers. While many specific theories have been superseded, his methods of analysis and categorization continue to influence how we organize and approach knowledge today.
