Pyrrhonian Skepticism: Equipollence and Suspension of Judgment

Introduction

Welcome to your final lesson in our module on Hellenistic Philosophy. In our previous sessions, you explored the ethical systems of the Epicureans and the Stoics. You saw how both schools proposed detailed, dogmatic systems—atomism for the Epicureans, and a rational, providential cosmos for the Stoics—as the foundation for achieving ataraxia, or tranquility. The Stoics, in particular, offered a rigorous path: live according to nature by distinguishing what is in your control from what is not.

Today, we turn to the third major school, Pyrrhonian Skepticism, which offers a radically different path to the same goal. The Pyrrhonian skeptic argues that tranquility is found not by discovering the right dogmatic system, but by demonstrating that for any philosophical claim, an equally strong opposing claim can be made. This leads to a suspension of judgment, which, perhaps surprisingly, results in peace of mind.

Your learning outcome is to analyze the Pyrrhonian skeptic's method of equipollence and suspension of judgment from Sextus Empiricus' 'Outlines of Pyrrhonism'. We will dissect the "how" of their philosophy: the specific argumentative tools they used to challenge dogmatic certainty and achieve their aim.

1. The Skeptic's Stance: Inquiry, Suspension, and Equipollence

Before we analyze the method itself, we need to clarify the skeptic's starting point and define our key terms. Unlike a modern "skeptic" who simply doubts or denies, the ancient Pyrrhonian was an inquirer.

To understand this stance and the core concepts, please start with this clear and accessible reading.

From this reading, we can establish our core vocabulary:

• Dogmatists: Philosophers who claim to have found the truth (e.g., Stoics, Epicureans).
• Academic Skeptics: Philosophers who claim that truth cannot be found.
• Pyrrhonian Skeptics: Philosophers who are still searching, and in the process, suspend judgment.
• Isosthenia (Equipollence): The state where opposing arguments appear to have equal strength or plausibility.
• Epoché (Suspension of Judgment): The mental state that follows from equipollence, where one refrains from assenting to any of the competing claims.
• Ataraxia (Tranquility): The peace of mind that unexpectedly follows from epoché.

With these terms in place, we can now ask: what is the method a Pyrrhonian uses to produce equipollence?

2. The Method: The Modes of Agrippa

The skeptics developed a set of argumentative strategies, called "Modes" or "Tropes," designed to generate equipollence for any dogmatic claim presented to them. While there were several sets of modes, the most philosophically powerful and general are the Five Modes attributed to a later skeptic named Agrippa.

These five modes function as a devastatingly effective logical toolkit for undermining any claim to justified knowledge. Given your background, the systematic, almost algorithmic nature of this toolkit should be of particular interest.

The following text from the Stanford Encyclopedia of Philosophy provides a rigorous, scholarly breakdown of these five modes.

The Five Modes essentially map out every possible path a justification can take and show why each path fails to provide a secure foundation. Let's summarize the core challenge, often called Agrippa's Trilemma:

When a dogmatist makes a claim (e.g., "The soul is immortal"), the skeptic asks for justification. The justification provided must fall into one of three categories:

1. Infinite Regress: The justification requires another justification, which requires another, and so on, forever. Since the chain never ends, the original claim is never secured.
2. Hypothesis (or Assumption): The chain of justification stops at a claim that is simply asserted without proof (e.g., a "first principle" or "axiom"). But if we allow unsupported assumptions, an opponent can simply assume the opposite, creating equipollence.
3. Circularity (or Reciprocality): The chain of justification eventually circles back to prove the original claim by using the claim itself as evidence.

This process is elegantly captured in the following flowchart:

Combined with the Mode of Dispute (pointing out that experts disagree) and the Mode of Relativity (pointing out that things appear differently from different perspectives), this trilemma forms a comprehensive system for inducing equipollence.

3. The Result: Tranquility as a Happy Accident

The skeptic does not set out to suspend judgment in order to find peace. Rather, they set out in search of truth, hoping to resolve the contradictions that trouble them. By applying the modes, they find that every argument is met by an equally strong counter-argument (equipollence), forcing them to suspend judgment (epoché).

It is only after this suspension that they find, to their surprise, the tranquility (ataraxia) they were originally seeking. The following video explains this crucial psychological component of the skeptical method, using a famous parable from Sextus Empiricus.

This accidental discovery is what separates Pyrrhonism from a dogmatic quest for a specific outcome. The skeptic does not have a theory that "suspending judgment causes tranquility." They simply report their experience: "I set out to resolve contradictions, I found I could not, I suspended judgment, and tranquility followed."

This non-dogmatic stance is reflected in the phrases the skeptics used to express their state of mind, such as:

• "I determine nothing."
• "Perhaps, possibly, maybe."
• And most directly, "To every argument an equal argument is opposed."

4. An Analytical Refinement: A Full Toolkit

A final question might arise: if Agrippa's Trilemma is so powerful, why did the skeptics need other modes, like the Ten Modes based on perceptual relativity, or the countless specific arguments catalogued by Sextus?

The answer reveals a final layer of sophistication in their method. The skeptic's goal is to produce a precise feeling of equipollence. This requires a toolkit with arguments of varying strengths.

As Brennan explains, if an opponent holds a belief weakly, only a weak counter-argument is needed to balance the scale. If they hold it strongly, a powerful "master argument" is required. The skeptic's method is not about using a single ultimate weapon, but about skillfully applying the right tool for the job to bring the intellect into a state of perfect balance.

Conclusion

In this lesson, you have analyzed the core method of Pyrrhonian Skepticism. You've seen that it is not a philosophy of lazy doubt, but a rigorous, active practice of inquiry that uses a sophisticated argumentative toolkit.

Here are the key takeaways on the skeptic's method:

• The Goal: The process begins with a desire for truth and relief from the disturbance of intellectual contradiction.
• The Tools: The skeptic employs Modes of Argumentation, most notably the Five Modes of Agrippa, to challenge any dogmatic claim.
• The Core Logic: Agrippa's Trilemma demonstrates that any attempt at justification must terminate in an unproven assumption, an infinite regress, or a circle.
• The Immediate Outcome: The application of the modes generates a state of equipollence (isosthenia), where opposing arguments appear equally strong.
• The Final Steps: Equipollence leads to suspension of judgment (epoché), which is then followed, as a happy accident, by tranquility (ataraxia).

You have now examined the three dominant Hellenistic schools. Each sought tranquility, but through starkly different means: the Epicureans through modest pleasure and the elimination of fear, the Stoics through virtuous reasoning and acceptance of fate, and the Skeptics through the suspension of all dogmatic belief.

In our next lesson, we will conclude this module by formally comparing these three distinct accounts of how to achieve ataraxia, synthesizing what you have learned about this fascinating period of philosophy.