Sextus Empiricus's Outlines of Pyrrhonism: Ancient Skepticism

Imagine two colleagues explaining why a project failed. One blames the plan; the other blames its execution. Each can answer the first objections you raise. You still have to decide what to do next, but you do not yet see a reason to endorse either explanation. Can you act while leaving the disputed question open?

Sextus Empiricus's Outlines of Pyrrhonism investigates a more demanding version of that possibility. His skeptic develops an ability to set appearances and arguments against one another. When they strike the inquirer as equally persuasive, judgment is suspended. Sextus also reports tranquility following that suspension. The qualification is that inquiry continues: the skeptic has neither discovered the truth nor established that discovery is impossible.

The project example is a modern illustration. Sextus is concerned with philosophical claims about reality, truth, and value, not a handbook for managing projects. The comparison gives us a way into his distinction between settling a disputed theory and finding enough practical guidance to proceed.

The opening of the Outlines separates three outcomes of investigation. A person may find what was sought, declare it beyond discovery, or continue searching. Sextus associates dogmatists with the first outcome, certain Academic philosophers with the second, and skeptics with the third. This is his classification of the positions, not a neutral verdict on everything the rival schools held (I.1–4).

That opening rules out a common misunderstanding. The Pyrrhonist does not announce that nothing can be known. Such a declaration would itself settle a philosophical question. Nor does Sextus describe skepticism as giving up inquiry for the sake of comfort. Its investigative character belongs to his account from the outset. At I.7 he also explains the name Pyrrhonian by reference to Pyrrho's conspicuous practice of skepticism, alongside names emphasizing investigation, suspension, and perplexity.

Sextus qualifies his own exposition too. He reports how matters appear to him at present rather than asserting that their reality must correspond to his account. That qualification applies to the skeptical account itself. It creates a challenge for the reader: how can someone explain a philosophical practice without turning that explanation into another doctrine? His answers concern the use of arguments and the status of the claims he makes with them.

At I.8–10, Sextus describes skepticism as an ability to oppose appearances and judgments in different ways. The opponents need not always be a proposition and its exact negation. What matters for the skeptical encounter is a conflict that leaves the inquirer unable to prefer one side. Arguments can be opposed to other arguments; conflicting appearances can also be brought into the discussion.

This is a demanding condition. The mere existence of disagreement does not establish equipollence. If one explanation strikes the inquirer as decisively better supported on the relevant objections, simply listing the two side by side will not reproduce the state Sextus describes. A modern reader should therefore resist using his modes as a license to give every opinion equal weight before examining it.

Nor does the equal-counterargument formula become a universal theorem that every possible argument must have an equally strong opponent. When Sextus explains that formula at I.202–203, he restricts it to dogmatic arguments examined so far and qualifies it by how they appear to him. At I.196, his account of suspending judgment similarly reports a current condition. Making permanent agnosticism an unchangeable commitment would go beyond these qualifications.

The skeptic does not deny that honey tastes sweet. Sextus grants that appearance while questioning the further assertion that honey is sweet in its underlying nature (I.19–20). The distinction concerns an experience and the account offered of the object. It is possible to acknowledge the former without treating it as a completed justification of the latter.

Likewise, when Sextus says the skeptic does not dogmatize, he distinguishes dogma in the relevant sense from ordinary assent to involuntary feelings. Someone feeling cold is not required to deny that feeling. The withheld assent concerns non-evident objects investigated in philosophical inquiry (I.13). We should retain that distinction rather than flatten his position into the claim that a skeptic assents to absolutely nothing.

There is a difficulty here, not a simple escape. Many ordinary statements seem to concern objects and their properties, not just passing feelings. How far can Sextus' distinction carry a person's life? The passages establish that he accepts involuntary appearances and practical guidance. Whether that leaves room for what we would ordinarily call beliefs requires careful interpretation; renaming every ordinary belief a mere appearance would not by itself answer the objection.

Sextus introduces modes, or patterns of opposition, that can lead toward suspension. He presents them without guaranteeing their number or cogency (I.35). The ten modes handed down by earlier skeptics organize differences concerning animals, human beings, senses, circumstances, positions and distances, mixtures, quantities, relations, frequency, and customs or beliefs (I.36–39). Their organizing question is how a claim about an object's nature can be settled when appearances vary with such conditions.

Consider a contemporary illustration of a change in circumstances. A quiet room might feel restful after a noisy journey and oppressive during an anxious wait. The circumstances affect how the room strikes the person. Recognizing that variation does not prove that the room has no properties. It does prompt a further question about which part of the judgment concerns the room and which part concerns the situation of the observer. This illustrates the kind of comparison involved in the fourth mode, which Sextus discusses through differences of condition at I.100.

The modes also direct attention beyond individual perception. Differences of customs, laws, and dogmatic assumptions can unsettle the thought that one inherited judgment transparently reveals what is naturally good or bad. But moving from conflicting customs to the assertion that every custom is equally good would add a conclusion the skeptical exercise does not establish. Suspension concerns the disputed account; it is not a proof of relativism.

Sextus also groups the modes by whether they concern the judging subject, the object judged, or both, and then places these groups under relation (I.38–39). That organization draws attention to how an appearance depends on a situation of judgment. It does not independently establish what the object is like outside that situation.

The ten modes thus supply varied material for opposition. We need not endorse every ancient example as a verified observation in order to understand the argumentative pattern. Its force in a particular case depends on whether the difference is relevant and whether the proposed way of settling it survives scrutiny. The modern room example is an invitation to examine a judgment, not a finding about all perceptions or a denial that observation can be useful.

The five modes attributed by Sextus to later skeptics concentrate the challenge to justification (I.164–169). Their distinctions are easier to follow when kept separate:

1. Disagreement: competing positions remain unresolved, leaving the inquirer without a basis for choosing between them.
2. Regress: the support offered for a claim requires further support, and that further support requires more, without an available starting point.
3. Relativity: an object appears in relation to the judging subject or to other things, while what it is independently remains disputed.
4. Hypothesis: an unsupported starting assumption is introduced to stop the demand for reasons.
5. Reciprocity: what is offered as support itself depends on the claim it was supposed to establish.

The familiar contrast between regress, unsupported assumption, and circularity should not obscure the other two modes. Sextus here attributes the five modes to later skeptics without naming Agrippa in his own text. Understanding how the modes work does not require settling the further history of their development.

Here is a modern illustration of reciprocity. A team treats a rating system as reliable because it agrees with an expert. Asked why the expert is reliable, it answers that the expert agrees with the rating system. Neither answer adds support independent of the disputed pair. This makes the circularity visible. It does not establish that every practical use of ratings has that defect, or that every form of mutually supporting evidence fails in the same way.

Sextus applies a related challenge to a criterion of truth, meaning a standard for judging which claims are true. At II.18–20, he asks how disagreement about such a criterion will be settled. An agreed criterion seems needed to decide the dispute, while deciding the dispute seems needed to secure an agreed criterion. Trying to prove the criterion introduces another reciprocal dependence if the proof itself needs that criterion. The point is a challenge to the proposed justification, not a discovered theorem that no standard can ever exist.

The practical objection is immediate: if assent is suspended, what guides action? Sextus distinguishes a criterion for deciding truth or existence from a criterion of action. Appearances supply practical guidance even while their philosophical interpretation remains under examination (I.21–22).

He describes a fourfold observance of everyday life. Natural capacities enable perception and thought. Necessary feelings lead a hungry person toward food and a thirsty one toward drink. Laws and customs provide inherited practices. Instruction in arts supplies learned activity. He describes these guides without giving them the status of dogmatic conclusions about reality (I.23–24).

The learned arts matter because his practical life is not reduced to reflexes. A person can engage in a skill and follow its instruction. In the project illustration, the analogous move would be to use an available procedure while continuing to examine the disputed explanation of failure. The comparison has a limit: if the team adopts provisional beliefs, that commitment still differs from withholding assent. We should not assume that such a team thereby lives Sextus' complete skeptical practice.

Following custom also creates an ethical problem. What happens when a community's practice is harmful? Sextus' account explains how action is possible without first establishing a philosophical theory. It does not automatically supply a defense of every custom or a developed principle for reforming unjust institutions. A critic can accept that suspension permits activity while still demanding an account of responsible resistance. Activity alone is not enough to establish that the activity is good.

Sextus reports that the original inquirer hoped to attain tranquility by settling which impressions or accounts were true. Instead, encountering equally persuasive opposition led to suspension, and tranquility followed as if by chance (I.12; I.25–26). The reported sequence reverses the expectation that peace requires finally winning the argument.

His explanation emphasizes beliefs about what is good or bad by nature. Someone who regards a possession as naturally good may become intensely anxious about obtaining it and then about losing it. The skeptic's withholding of that judgment removes a source of added disturbance in Sextus' account (I.27–28). This is his philosophical explanation, not a controlled psychological finding about how everyone responds to uncertainty.

Sextus illustrates the unexpected arrival of tranquility with a story about the painter Apelles. Unable to paint a horse's foam, the painter supposedly threw a sponge at the picture and produced the desired effect. Sextus reports the story as an analogy (I.28–29); we need not treat it as independently verified biography. Its point is the unexpected result of abandoning an unsuccessful route, not a prescription to stop examining arguments.

The qualification about unavoidable feelings is essential. Sextus explicitly denies that the skeptic is wholly untroubled in every circumstance (I.29–30). Confusing the removal of an added judgment with immunity to pain turns his account into a promise it does not make. A present-day reader can question the reported connection between suspension and calm without first attributing that stronger promise to him.

If skepticism asserts that every claim is unjustified, that assertion seems to need justification too. Sextus' response depends on declining to assert such a doctrine. His skeptical expressions describe how the inquirer is affected. They include themselves within their scope rather than establishing a set of truths exempt from their own scrutiny.

At I.206, he compares the expressions to purgative medicines that remove themselves along with what they expel. The comparison suggests an argumentative use that does not require retaining the argument as an ultimate doctrine. At the end of the work, he also compares arguments of different strengths with medicines adjusted to different patients' conditions (III.280–281). These passages present a therapeutic purpose for argument. They do not establish that any false or manipulative argument becomes acceptable whenever it makes someone feel better.

A critic can still press the distinction between a report and an assertion. If Sextus expects us to learn from his account, why should its repeated usefulness not count as a reason to believe it? If he is only describing his present experience, how far should anyone else follow it? Those questions test whether his self-qualification can preserve the explanatory ambitions of the book. Restating the medicine image does not settle them.

Return to the two explanations of project failure. Before choosing a side, ask whether the disagreement concerns the same claim, what evidence each side accepts, and whether its reasons depend on what is disputed. You might find an answer that changes the balance. You might instead identify what further observation is needed. These are possible outcomes of examination, not guarantees that every dispute ends in suspension.

For a personal example, imagine receiving an abrupt message and taking it as evidence of hostility. Reconsidering the circumstances could expose a gap between how the message strikes you and a settled claim about its sender's intention. The exercise might alter the judgment; it might leave you uncertain. It gives no assurance of emotional relief, and it does not establish that harmful conduct should be ignored.

Sextus asks a harder question than whether occasional open-mindedness is useful. Can the sustained distinction between appearances and dogmatic assent support inquiry and life? His answers deserve to be tested through the modes, the practical criterion, and the limits he places on tranquility. Continuing to investigate is compatible with acknowledging that the present exchange has failed to settle its question. Calling the result a cure for certainty would settle too quickly what his account leaves for continuing investigation.

• Sextus Empiricus, Outlines of Pyrrhonism, translated by R. G. Bury. The Tufts/Open Greek and Latin text provides numbered sections across all three books.
• Sextus Empiricus, Pyrrhonic Sketches, Book I, translated by Mary Mills Patrick, in Sextus Empiricus and Greek Scepticism. Distinguish the translated primary text from Patrick's own introductory study.
• Plato, Meno, translated by Benjamin Jowett, especially 80d–86c. Compare the problem of beginning inquiry without already possessing its answer.