Presocratic Philosophers: Unveiling the Origins of Cosmos

Presocratic Philosophers and the Cosmos

Presocratic philosophers sought to explain the origin and constitution of the cosmos. They aimed to discover the principle (arche) of the universe, focusing on what they called 'naturaleza' (nature) rather than anthropomorphic deities. This marked the beginning of philosophy and science. The cosmos was naturalized, meaning nature became distinct from the 'divine' and 'sacred'.

What did 'physis' mean to these early philosophers? It represented the original matter from which everything is composed, the source and destination of all things, the organizing principle of reality, and the process of genesis and generation.

The Ionian School

Thales: He initiated the logical investigation of nature, asserting that things are alive and lively (hylozoism). His principle was water, endowed with life and movement.

Anaximander: His principle was Apeiron (the indefinite), a non-concrete material reality from which the universe was formed through an orderly process, a process of justice.

Anaximenes: His principle was air, from which all things originate. Rarefaction produces fire, while condensation produces heavier elements. He also argued that breath animates man and keeps him alive.

The Eleatic School

Parmenides: His poem consists of a 'Preface' and two parts: 'The Way of Truth' and 'The Way of Opinion'. The 'Preface' is an invocation to the Muses, describing a journey to the abode of the Goddess, who reveals two paths of knowledge and the need to choose one: Truth or Opinion.

Choosing the path of truth implies embracing the principle of identity and non-contradiction. Choosing the path of opinion involves reviewing 'thinkable things' through sensory experience. According to the way of truth:

• Being is.
• Non-being is not.
• Being is unique, without vacuum.
• Being is without beginning or end, eternal.
• Being is continuous; discontinuity would imply gaps of non-being.
• Being is immobile; movement would mean ceasing to be in one place to be in another.

Zenon: Founder of dialectic, he developed famous paradoxes to support Parmenides' theory of being. The most famous is Achilles and the tortoise: Achilles can never overtake the tortoise if it has a head start, because to do so, he must pass through the midpoint of the space that separates them.