The history of philosophy notes #1 - Presocratics

 I've started to listen to the podcast The history of philosophy without any gaps by Peter Adamson (Spotify) and it blew my mind.

I've already listened to 30 episodes and it's very entertaining. I made up my mind to collect my thoughts and notes on the topic here so I have something to come back to when I get interested in the topics again. Enjoy!

1. Thales of Miletus: Often regarded as the first philosopher in Western history, Thales proposed that water is the fundamental substance (arche) of the universe. He believed that everything originated from water and that the Earth floats on water. Thales is also credited with predicting a solar eclipse and contributing to geometry and astronomy.
2. Anaximander: A student of Thales, Anaximander introduced the concept of the "apeiron" (the boundless or infinite) as the origin of all things. He argued that the apeiron is an eternal and ageless substance that generates the opposites (such as hot and cold, wet and dry) which in turn create the world. Anaximander also made significant contributions to geography and biology.
3. Anaximenes: Another Milesian philosopher, Anaximenes suggested that air is the primary substance and that other forms of matter are created through processes of condensation and rarefaction. He believed that air, when condensed, becomes wind, then cloud, water, earth, and finally stone. Conversely, when rarefied, air becomes fire. Anaximenes' ideas represented a more tangible and observable approach compared to his predecessors.
4. Xenophanes: Known for his critique of traditional Greek religion and anthropomorphic gods, Xenophanes proposed a single, eternal god that is unlike humans in form or thought. He argued that this god is all-seeing, all-hearing, and all-knowing, and that it does not resemble mortals in any way. Xenophanes also contributed to epistemology, questioning the possibility of certain knowledge.
5. Pythagoras: Famous for his contributions to mathematics, particularly the Pythagorean theorem, Pythagoras also believed in the transmigration of souls (reincarnation) and that numbers are the essence of all things. He founded a religious and philosophical community in Croton, where his followers adhered to strict rules and studied mathematics, music, and astronomy. Pythagoras' ideas influenced later philosophical thought, particularly Platonism.
6. Heraclitus: Known for his doctrine of change, Heraclitus asserted that everything is in a state of flux and that fire is the fundamental element. He famously stated that "you cannot step into the same river twice," emphasizing the constant change in the universe. Heraclitus also introduced the concept of the "logos," a rational principle that governs the cosmos and maintains order amidst change.
7. Parmenides: A founder of the Eleatic school, Parmenides argued that change is an illusion and that reality is unchanging and indivisible. He posited that what truly exists is a single, eternal, and unchanging being, and that all perceptions of change and plurality are mere illusions. Parmenides' ideas challenged the views of earlier philosophers and had a profound impact on the development of metaphysics.
8. Zeno of Elea: A student of Parmenides, Zeno is famous for his paradoxes, which were designed to support Parmenides' view that change and plurality are illusions. His paradoxes, such as the Achilles and the Tortoise and the Dichotomy paradox, aimed to show the logical contradictions in the common-sense understanding of motion and plurality. Zeno's work laid the groundwork for later developments in logic and mathematics.
9. Melissus: Another Eleatic philosopher, Melissus extended Parmenides' ideas, arguing that reality is infinite and unchanging. He maintained that what exists is one, eternal, and unbounded, and that it cannot be destroyed or altered. Melissus' arguments further reinforced the Eleatic school's emphasis on the unity and permanence of being.
10. Democritus: Along with Leucippus, Democritus developed the theory of atomism, which posits that everything is composed of small, indivisible particles called atoms. He believed that these atoms move through the void and combine to form the various objects and phenomena in the world. Democritus' materialistic and mechanistic view of the universe influenced later scientific thought and laid the foundation for modern atomic theory.
11. Leucippus: Often credited as the founder of atomism, Leucippus proposed that the universe is composed of atoms and void. He argued that atoms are infinite in number, indivisible, and in constant motion. Leucippus' ideas were further developed by his student Democritus, and together they provided a naturalistic explanation for the diversity and change observed in the world.
12. Empedocles: He introduced the idea of four root elements (earth, air, fire, and water) and proposed that two forces, Love and Strife, cause the mixture and separation of these elements. According to Empedocles, Love brings elements together to form compounds, while Strife separates them. His cosmological theory aimed to explain the processes of generation and destruction in the natural world. Empedocles also made contributions to biology and medicine, including the theory of the four humors.

These Presocratic philosophers laid the groundwork for Western philosophy by moving away from mythological explanations and seeking natural, rational explanations for the cosmos. Their inquiries into the nature of reality, substance, and change set the stage for later philosophical developments and continue to influence contemporary thought.