Lesson 2.1: Not of this World (Pt. I)

Glossary

Philosophical Concepts

• Platonism – The philosophical system derived from Plato’s works, emphasizing the existence of non-physical realities (the Forms) and the importance of reason in achieving knowledge.

• Forms (Ideas) – Eternal, unchanging, non-physical entities that define the true essence of things. For example, all chairs share in the Form of Chairhood, and all beautiful things partake in the Form of Beauty.

• Platonic Heaven – A metaphorical term for the realm where the Forms exist, separate from the physical world.

• Dualism – The belief that reality consists of two fundamentally different substances, such as the material world and a non-material realm (e.g., soul and body, or physical world and the Forms).

• Substance Dualism – The view that minds (or souls) are wholly non-physical and can exist independently of the body.

• Materialism – The belief that only physical things exist; Plato rejected this in favor of the existence of non-physical Forms.

• Nominalism – The belief that universals (like Chameleon-ness or Chairhood) do not exist independently; they are merely names we assign to groups of things. Plato opposed this, arguing that universals exist as Forms.

• Relativism – The idea that truth or morality is not absolute but depends on perspective, culture, or individual belief. Plato refuted this idea, particularly in his critique of Protagoras.

• Skepticism – The philosophical position that doubts the possibility of certain or absolute knowledge. Plato opposed skepticism, believing that knowledge was possible through the rational mind and the Forms.

• Moral Realism – The belief that moral truths exist independently of human beliefs, preferences, or cultures. Plato was a strong advocate of this view.

• The Good – The highest and most important of the Forms; it is the source of all truth and knowledge in Plato’s philosophy, analogous to the sun in his Allegory of the Cave.

• The Divided Line – Plato’s metaphor for levels of knowledge, ranging from illusion to true understanding: reflections → physical objects → mathematical reasoning → knowledge of the Forms.

Plato’s Intellectual Influences & Opponents

• Socrates – Plato’s teacher and the main character in most of his dialogues. Socrates' focus on ethical definitions and dialectical questioning heavily influenced Plato.

• Heraclitus – A pre-Socratic philosopher who emphasized that everything is in flux; Plato partially accepted this but contrasted it with his theory of eternal Forms.

• Parmenides & the Eleatics – Philosophers who argued that reality is unchanging and that change is an illusion; Plato blended this idea with Heraclitus' doctrine of flux.

• Pythagoreanism – A mystical school of thought that saw mathematics as fundamental to reality; Plato was heavily influenced by Pythagorean ideas, particularly regarding the eternal nature of mathematical objects and their connection to the Forms.

• Democritus – The philosopher of atomism, whom Plato conspicuously ignored, possibly because Democritus’ materialism contradicted his own ideas.

• The Sophists – A group of traveling teachers who emphasized rhetoric, persuasion, and relativism; Plato opposed them for teaching skills without concern for truth or virtue.

• Protagoras – A Sophist who famously said, "Man is the measure of all things," meaning truth is relative; Plato refuted this idea in the Theaetetus.

Key Dialogues & Arguments

• Apology & Crito – Dialogues where Plato presents Socrates’ commitment to virtue as a good that demands unconditional obedience, much like military orders.

• Republic – One of Plato’s most famous works, covering justice, the ideal state, and the philosopher-king; it also contains the Allegory of the Cave, the Theory of Forms, and the Tripartite Soul.

• Phaedo & Meno – Dialogues discussing the Argument from Recollection, which claims that knowledge is not learned but remembered from a previous existence.

• Symposium – Explores love and beauty, suggesting that the Form of Beauty is the most tangible of the Forms in the physical world.

• Timaeus – Discusses Plato’s cosmology, where the universe is created with mathematical order, influenced by Pythagorean thought.

• Theaetetus – Examines knowledge and criticizes relativism, particularly Protagoras’ idea that truth is subjective.

• Laws – A late work where Plato refines his political philosophy, incorporating ideas of divine justice and moral education.

Other Recurring Ideas in Plato’s Thought

• Tripartite Soul – Plato’s theory that the soul consists of three parts: reason (logos), spirit (thumos), and appetite (epithumia). Happiness comes from reason governing the other parts.

• Philosopher-King – The idea that only philosophers—those who understand the Forms—should rule, as they alone have access to true knowledge.

• Metaphysics & Ethics Connection – Plato believed ethics, metaphysics, and epistemology were intertwined: to know the Good is to be good.

• Assimilation to God – The belief that the highest form of human happiness comes from aligning oneself with the rational order of the cosmos, making oneself “like God.”

Words You Might Not Know

• Elenchus – The Socratic method of questioning to expose contradictions in someone’s beliefs.

• Dialectic – A method of reasoning and discussion aimed at discovering truth, used heavily in Plato’s dialogues.

• Reductionism – The attempt to explain complex things in terms of simpler elements; Plato opposed this, especially regarding knowledge and morality.

• Empiricism – The belief that knowledge comes primarily or exclusively through sensory experience; Plato rejected this in favor of reason and innate knowledge of the Forms.

• Axiomatization – The process of establishing fundamental principles in a field (e.g., Euclidean geometry); Plato’s Academy contributed to this in mathematics.

• Logos – A Greek term meaning “reason” or “rational principle”; in Plato’s view, this is the organizing principle of the cosmos.

• Mysticism – The belief that one can attain direct, often divine, knowledge of reality beyond rational thought; some aspects of Plato’s thought (e.g., purification of the soul, reincarnation, ascent to the divine) have mystical elements.

• Monotheism – The belief in one God; some scholars see Plato’s thought as part of an evolving monotheistic tradition leading to Stoicism.

• Eleusinian Mysteries – A secret religious initiation in ancient Greece, linked to Demeter and Persephone; Plato referenced these rites, and some scholars suggest they involved psychedelics.