The Milesian School, led by Thales, Anaximander, and Anaximenes, marked the beginning of Western philosophy. They sought natural explanations for phenomena, rejecting mythological accounts and introducing the concept of arche as the fundamental substance of the universe.

These early Greek thinkers made significant contributions to various fields, including geometry, astronomy, and geography. Their ideas about the arche - water, apeiron, and air - laid the foundation for rational inquiry and scientific thought, influencing future philosophers and scientists.

The Milesian School

Contributions of early Greek philosophers

• Thales
  • Widely regarded as the first Western philosopher who sought natural explanations for phenomena instead of relying on mythological accounts
  • Proposed water as the fundamental substance (arche) from which everything in the universe originated
  • Developed a theory that the Earth floated on a vast ocean of water
  • Made significant contributions to the fields of geometry (Thales' Theorem) and astronomy (predicted a solar eclipse in 585 BCE)
• Anaximander
  • Student and successor of Thales who introduced the concept of the "apeiron" (the boundless, indefinite substance) as the arche
  • Argued that the Earth was suspended in space and not resting on water or any other substance
  • Created the first known map of the world, which represented a significant advancement in geography
  • Proposed a theory of the origin of life, suggesting that humans evolved from fish
• Anaximenes
  • Student of Anaximander who identified air as the primary substance (arche) of the universe
  • Explained natural phenomena, such as the formation of clouds and rain, through the processes of rarefaction (thinning) and condensation (thickening) of air
  • Believed that the Earth was flat and floated on a cushion of air, similar to a leaf

Concept of arche in Milesian thought

• The arche is the fundamental principle, source, or substance from which all things in the universe originate
• Milesian philosophers sought to identify a single, universal arche that could explain the diversity and complexity of the world
• The concept of the arche marked a significant shift from mythological explanations of the world to natural, rational ones
• Identifying the arche was an attempt to find unity, coherence, and a common cause behind the apparent chaos and multiplicity of the universe
• The arche was seen as the primary cause of all things, the source of all change, motion, and the ultimate foundation of reality

Archai of Milesian philosophers

• Thales: Water
  • Believed that water was the source of all life and the fundamental building block of the universe
  • Observed that water could exist in different states (liquid, solid, and vapor), suggesting its versatility and adaptability
  • Saw moisture as essential for life, growth, and nourishment (plants, animals, and humans all depend on water)
• Anaximander: Apeiron (the boundless)
  • An indefinite, infinite, and eternal substance that is not associated with any particular element or quality
  • Generates the opposites (hot/cold, wet/dry) through a process of separation and differentiation
  • Accounts for the balance, equilibrium, and cyclical nature of the world (opposites constantly interacting and transforming)
• Anaximenes: Air
  • A tangible and observable substance, unlike Anaximander's abstract and indefinite apeiron
  • Can undergo rarefaction (becoming fire) and condensation (becoming wind, clouds, water, earth, and stone), explaining the formation of different substances
  • Sustains life through the process of breathing, which is common to all living beings
  • Offers a more concrete, empirical, and relatable arche compared to Anaximander's apeiron

Milesian School's impact on philosophy

• Marks the beginning of Western philosophy and science by shifting focus from mythological explanations to natural causes and rational inquiry
• Introduces the concept of the arche as a unifying principle that can explain the diversity and complexity of the world
• Encourages observation, experimentation, and logical reasoning as methods for understanding the nature of the universe
• Lays the foundation for later philosophical and scientific thought by influencing subsequent pre-Socratic philosophers (Pythagoras, Heraclitus, Parmenides)
• Contributes to the development of various branches of knowledge, including cosmology (theories about the structure and origin of the universe), astronomy (Thales' eclipse prediction), and geography (Anaximander's world map)
• Represents a crucial step in the transition from theocentric (god-centered) to naturalistic (nature-centered) worldviews, paving the way for the further development of rational thought and scientific inquiry