Anaximenes of Miletus

"Just as," he said, "our soul, being air, holds us together, so do breath and air encompass the whole world." (Aetius, Placita Philosophorum)

Anaximenes of Miletus, born around 588 BCE and active until approximately 502 BCE, was a pre-Socratic philosopher from the ancient city of Miletus in Ionia. He is often considered the third of the great Milesian philosophers, following Thales and Anaximander.

Philosophical Foundations

The central pursuit of the Milesian philosophers was to identify the 'archê', or the primary substance from which all things originate and to which they return. While Thales posited water and Anaximander proposed the boundless 'apeiron' as the primary substances, Anaximenes chose 'air'.

Air as the Fundamental Substance

Anaximenes believed air to be more than just the gaseous substance enveloping the Earth. To him, it was the very fabric of existence. He postulated that air, through processes of condensation and rarefaction, could transform into all other substances in the world. This continuous change and transformation underpin the dynamic nature of existence.

Empirical Observations

Anaximenes' ideas were rooted in everyday observations. He noticed that when we exhale with our mouths closed, we release warm air (like fire), but when we exhale with our mouths open, the air is cooler (like wind). From this, he inferred that temperature differences could change the state of air. Similarly, he might have observed how water evaporates into air and how cold causes moisture to condense, further supporting his theories.

Was Anaximenes Right?

While Anaximenes' idea of air as the primary substance might seem rudimentary by today's standards, it marked a significant step in philosophical thought for several reasons:

1. Empirical Foundations: Anaximenes based his ideas on observation, a foundational principle for modern scientific methodology.
2. Concept of Transformation: The idea that one substance can transform into another based on certain processes is somewhat mirrored in modern science. For instance, the states of matter (solid, liquid, gas) change based on temperature and pressure.
3. Monism: Anaximenes' belief in a single substance as the source of everything finds parallels in modern physics, where researchers seek a unified theory to explain all forces and particles.

Legacy and Influence

Anaximenes' focus on observation and his belief in a transformative primary substance influenced subsequent Greek philosophers. While his specific doctrine of air did not become a central tenet in later thought, his methodological approach and quest for a fundamental substance set the stage for richer and more complex philosophical and scientific explorations.