Philosophical Arguments from Parmenides to Nietzsche

Parmenides’ Refutation of Change

Parmenides was a Greek scholar who lived in the fifth century BCE in the Italian colony of Elea. He championed the Eleatic school, known for claiming that reality is a timeless unity. According to this philosophy, change and the passage of time are mere illusions or projections of the mind. Only fragments of Parmenides' works survive today, including his significant argument against change, which may constitute the earliest surviving example of extended philosophical argumentation.

Main Argument Against Change

The principal fragment attributed to Parmenides outlines a series of connected points aimed at demonstrating the impossibility of change. He argues that any notion of change involves either destruction or creation. Specifically, he states that it entails either an object transitioning from existence to non-existence (or vice versa) or a property changing from being instantiated to not being instantiated (or vice versa).

Parmenides suggests that any change thus requires something that both "is" and "is not," which leads to an apparent contradiction. He anticipates a resolution to this contradiction that posits no inconsistency in an item or property being and not being at the same time. For instance, he acknowledges that one might argue an object can "be" in the present while "not be" in the past or future. However, Parmenides counters this claim by stating that it only shifts the contradiction to the realm of temporal change.

The Implications of Change and Time

By taking change seriously, one must contemplate past and future times as real; yet, past and future are distinct from the present in Parmenides' view, as the present “is,” while the past and future “are not.” To think of past and future as real involves regarding them as real now, which would render them present. Thus, contemplating change requires a dual acknowledgment that the past and future are both present and not present, real and not real. Consequently, Parmenides resolves this contradiction by denying the reality of both change and the passage of time.

This line of reasoning serves as a precursor to J. M. E. McTaggart's early twentieth-century argument reaching a similar conclusion: sensory perception, characterized by change, is inherently deceptive. According to Parmenides, the only path to discovering the truth about the world is by disregarding sensation and relying solely on reason and logic.

Structure of Parmenides’ Argument

Parmenides presents a reductio ad absurdum argument structured as follows:

  1. P1: Change is real (assumption for reductio).

  2. P2: If change is real, then it involves either:

    • (a) an object coming into existence or beginning to have some property,

    • (b) an object becoming non-existent or ceasing to have some property.

  3. P3: If P2 is true, then there are different times, i.e., past, present, and future.

  4. C1: Therefore, there are different times (hypothetical syllogism of P1, P2, P3).

  5. P4: There are not different times—only the present exists.

  6. C2: Therefore, there are different times and not different times (conjunction of C1 and P4).

  7. C3: Conclusively, change is not real (reductio, from P1 and C2).

Philosophical Context

Parmenides does not explore rejecting premises in a way that would allow a definition of change consistent with a static theory of time. This omission parallels McTaggart's later viewpoint. Nonetheless, Parmenides’ argument still stands as a valid challenge to the dynamic theory of time.

Quote from Parmenides

Parmenides elaborates:

"As yet a single tale of a way remains, that it is; and along this path, markers are there very many, that What Is is ungenerated and deathless, whole and uniform, and still and perfect; but not ever was it, nor yet will it be, since it is now together entire, single, continuous; for what birth will you seek of it? How, whence increased? From not being I shall not allow you to say or think: for not to be said and not to be thought is it that it is not. And indeed what need could have aroused it later rather than before, beginning from nothing, to grow?"

This passage captures Parmenides' core belief that existence is singular and unchanging, and that notions of birth or death are inadmissible. He concludes that it "is or it is not," with the certainty that what is, is genuine and unchanging.

Summary of Parmenides’ Arguments

  1. P1: Change implies real difference in time (past/present/future).

  2. P2: Acknowledging change requires accepting both existence and non-existence.

  3. Conclusion (C3): Change, being contradictory, cannot be real—therefore, it does not exist.

In essence, Parmenides' philosophy lays a foundational framework for addressing the nature of reality and existence, presenting significant challenges to later philosophers, including Plato and Aristotle, regarding the understanding of change, time, and knowledge itself.

The Existence of Forms: Plato’s Argument from the Possibility of Knowledge

Plato, notably in his dialogues, emphasizes the existence of Forms, which are central to his philosophy. The existence of these Forms underpins what can reasonably be termed Plato’s philosophy—removing them undermines his entire framework of thought. Plato presents several arguments for the existence of Forms, with one of the most significant being the “argument from the possibility of knowledge.” This argument can be constructed from various dialogues.

Influences on Plato's Thought

Plato was deeply influenced by Socratic ideals, particularly the pursuit of wisdom and genuine knowledge, accompanied by disdain for the pretensions of contemporary thinkers, such as the Sophists. Additionally, he grappled with the contrasting views of Heraclitus, who asserted that nothing is, only becoming, and Parmenides, who claimed that change does not exist, only a singular, unchanging entity.

The Argument from the Possibility of Knowledge

The foundation of Plato's argument hinges on the premise that if everything is constantly changing—as Heraclitus claimed—then comprehending any entity becomes impossible. By the time knowledge is grasped, it slips from one's understanding due to its transient nature. Therefore, to know something must imply understanding something eternal and unchanging (reflective of Parmenidean philosophy). Only immutable entities can be truly known, leading Plato to conclude that since such entities do not exist in our world, they must reside in a nonspatial, nontemporal realm, which he refers to as Forms.

Distinction Between Knowledge and Perception

Plato’s argument distinguishes the essence of knowledge from mere opinion or belief. In his dialogues, particularly Cratylus, Socrates discusses the distinction:

"When a man knows, must there not be something that he knows? … So if the real is the object of knowledge, the object of belief must be something other than the real."

Here, Socrates delineates between true knowledge, which concerns stable entities (the Forms), and mere belief, which pertains to the fluctuating world of appearances.

Example of Knowledge and Belief

In The Republic, Plato explores this idea with the following exchange:

"[I]f we contrast a man who believes in the existence of beautiful things but not in Beauty itself … is he not living in a dream?"

This example illustrates that true knowledge involves comprehending the essence (in this case, the Form of Beauty), while mere belief refers to perceptions of transient beautiful objects.

Structure of the Argument

The argument from the possibility of knowledge can be summarized as follows:

  1. P1: Knowledge is possible.

  2. P2: Knowledge is knowledge of some object. Thus, if a piece of knowledge lacks an object, it does not exist.

  3. P3: All knowledge (unlike opinion) is stable, i.e., all pieces of knowledge remain constant over time; they do not change.

  4. P4: If the object of knowledge could change, then the knowledge of that object could not remain stable.

  5. P5: All things in this world are in constant flux (Heraclitus’ assertion).

  6. P6: Some objects of knowledge exist among things in this world (assumption for reductio).

  7. C1: Some objects of knowledge change; they are unstable (based on P5 and P6).

  8. C2: Therefore, some pieces of knowledge are unstable (according to P4 and C1).

  9. C3: This results in a contradiction since it implies that all knowledge is stable and some pieces are not.

  10. C4: Hence, no objects of knowledge exist in this world, led by the contradiction encountered above.

  11. P7: If objects of knowledge do not exist in this world, they also cannot exist in another.

  12. P8: Objects of knowledge do not exist in another world (assumption for indirect proof).

  13. C5: Thus, objects of knowledge do not exist in both worlds (combined statement of C4 and P8).

  14. C6: Therefore, objects of knowledge do not exist.

  15. C7: This leads to the conclusion that knowledge is not possible (based on P2 and C6).

  16. C8: Here we are left with a contradiction since we previously affirmed that knowledge is possible.

  17. C9: Thus, objects of knowledge—referred to as Forms—must indeed exist in another realm.

Through these explorations, Plato illustrates the necessity of Forms as the ultimate source of knowledge, positioning them centrally in his philosophical discourse.