Parmenides of Elea: Logic Demands a Changeless Universe by Leonard Peikoff, part 4 of 50

Parmenides: The Philosopher of Being

Introduction to Parmenides

• Parmenides, a philosopher from Elea, flourished around 480 BC and represents a contrasting viewpoint to Heraclitus.

• Unlike Heraclitus, who expressed his ideas oracularly, Parmenides presents reasoned arguments in the form of a connected poem.

Core Philosophy

• Parmenides' fundamental principle is encapsulated in the assertion: "What is is, and what is not is not." This means that non-existence cannot be conceived or thought about.

• He emphasizes two paths of inquiry: one affirming existence ("what is") and another denying it ("what is not"), which he claims cannot be learned.

Critique of Heraclitus

• Parmenides directly opposes Heraclitus's view that everything embodies contradictions (i.e., being and non-being).

• He describes those who accept Heraclitus's philosophy as "mortals knowing not," suggesting they are confused and lack true understanding.

Implications of Existence

• According to Parmenides, reality exists solely as "what is," meaning only existence can be thought about; concepts of non-existence are invalid.

• He challenges listeners to think about nothingness, asserting that any attempt leads back to thinking about something—thus reinforcing his claim that "you cannot know what is not."

Systematic Deductions

• From his principles, Parmenides concludes that the universe must be uncreated; if it had an origin, there would have been a state of nothing before existence.

• Additionally, he argues the universe must be indestructible; if it could cease to exist, then what remains would be non-existence—which contradicts his core tenet.

Conclusion on Existence

• Ultimately, according to Parmenides' reasoning, the universe is eternal with no beginning or end. This perspective diverges significantly from religious views on creation.

Understanding Parmenides' Philosophy

The Concept of Vacuum and Plenum

• Parmenides argues against the existence of a vacuum, stating that "what is not is not," leading to the conclusion that the universe is a plenum—a solidly packed entity with no empty spaces.

• The term plenum means "full," indicating that there are no gaps or voids in the physical world; it is described as a massive ball of tightly packed matter.

Parmenides' Deduction on Change

• He asserts that change is impossible, claiming that all forms of motion or alteration are illusions. This perspective leads him to deny any form of change, including natural processes like growth.

• Using the example of a seed growing into a flower, he illustrates his point: at one moment, the seed exists (what is), and at another moment, it transforms into a flower (what is not). Thus, he concludes that every change involves transitioning from what exists to what does not exist.

Implications of Change Denial

• According to Parmenides, since change involves referencing what does not exist (the non-being), it must be irrational; therefore, he posits that the world remains completely motionless and changeless.

• Both Parmenides and Heraclitus agree on one crucial aspect: change implies contradiction; however, they diverge in their conclusions—Heraclitus embraces change while Parmenides rejects it based on logical reasoning.

Monism and Multiplicity

• Following his denial of change, Parmenides also denies multiplicity; he believes there cannot be different entities if everything consists of one undifferentiated substance—a monist view.

• He questions how one could distinguish between different things when everything is part of this singular plenum without spaces separating them; thus, multiplicity becomes an illusion in his philosophy.

Conclusion on Reality Perception

• For Parmenides, true reality differs from sensory perception; senses can deceive us by presenting appearances rather than truth. True understanding comes through logic and reason rather than empirical observation.

• His ideas laid foundational concepts for later philosophical discussions about being and reality which Aristotle would later address in his metaphysical inquiries.

Philosophical Catastrophe: The Dilemma of Change and Multiplicity

The Philosophical Crisis

• A significant philosophical crisis arises at the beginning of Western philosophy, where two opposing views emerge regarding change and existence.

• One philosopher argues that everything changes and nothing is stable, while another claims that nothing changes, asserting the existence of a motionless reality.

• This conflict sets the stage for subsequent philosophical inquiry, which struggles to reconcile these contradictory positions until Aristotle's time.

Zeno's Paradoxes

• Zeno, a follower of Parmenides (490-430 BC), introduces paradoxes aimed at demonstrating the impossibility of motion and multiplicity.

• One notable paradox suggests that crossing a room is impossible because one must first cover half the distance, then half of that distance ad infinitum.

The Motion Paradox

• Zeno argues that if distances can be infinitely subdivided, crossing any finite distance would require an infinite amount of time.

• This leads to the conclusion that motion itself is an illusion since one cannot traverse an infinite number of subdivisions within a finite lifespan.

The Multiplicity Paradox

• Zeno also challenges the concept of multiplicity by arguing against the idea that the universe consists of many parts or entities.

• He posits that if we accept parts exist in an infinitely divisible universe, it leads to contradictions about size and infinity.

Contradictions in Multiplicity

• If every part can be divided indefinitely, this implies there are infinitely many parts in the universe.

• Consequently, this results in an infinitely large universe due to infinite subdivisions leading to infinite quantities.

Ultimate Constituents

• Zeno questions what size ultimate indivisible parts would have; he concludes they must be zero in size for meaningful discussion about wholes with parts.

Conclusion on Indivisibility

• Thus, if there are no sizes for these ultimate constituents (zero), it contradictorily suggests both an infinitely large universe with endless parts and an infinitely small universe with sizeless components.

• Therefore, Zeno concludes there cannot be multiplicity; Parmenides' assertion stands—there exists only one indivisible reality.

Understanding Infinity and the Nature of the Universe

The Philosophical Inquiry into Infinity

• The discussion begins with Aristotle's approach to infinity, highlighting the need for a theory of infinity to address related paradoxes.

• A pragmatic assumption is made regarding motion between two points, suggesting that philosophical validation will be explored in future discussions.

The Concept of Vacuum in Philosophy

• The speaker aligns with Parmenides' argument that true vacuums do not exist; there is always something present in what we perceive as empty space.

• Historical theories, such as ether filling empty spaces, are mentioned, indicating a belief that some form of medium must exist even if it is not fully understood.

Change and Its Classifications

• Early philosophers struggled to differentiate types of change; Plato and Aristotle later classified changes into categories like locomotion, substance change, quantity change, and quality change.

• This classification helped resolve many philosophical problems by clarifying misunderstandings about different kinds of change.

Perspectives on the Universe's Shape

• The speaker reflects on Heraclitus' view that "everything flows," contrasting it with Parmenides’ ideas about the universe’s shape and structure.

• Agreement with Parmenides is expressed regarding the universe being finite but lacking an external shape or boundary; questioning what lies outside the universe is deemed meaningless.

Visualization Challenges

• It’s emphasized that one cannot project themselves outside the universe to visualize its shape; all existence occurs within it.

• A mental exercise is suggested: envisioning a dot expanding until it fills one's mental screen represents understanding the universe's limits without attempting to see beyond them.