Skip to content
Wellsprings
epistemology

The Modes of Skepticism

τρόποι

The skeptics' toolkit: a numbered set of standard arguments — ten of them, then a tighter five — engineered to suspend judgment by showing that every claim can be opposed.

The Pyrrhonist skeptics, particularly Aenesidemus in the first century BCE, systematized arguments against dogmatic claims to knowledge through what they called the "modes" or *tropoi*—standardized lines of reasoning showing how judgment varies depending on circumstances. The Ten Modes covered differences between animals, between individual humans, between sensory organs, between conditions and circumstances, between distances and positions, between quantities and composition, between familiarity, between customs and laws, between reasonable hypotheses, and between what appears frequent versus rare. Each mode demonstrated that the same object produces conflicting impressions, preventing certain knowledge.

These modes functioned as practical tools for inducing *epochē*, suspension of judgment. For instance, the seventh mode showed how the sun appears enormous from far away but tiny when viewed through a tube, or how square towers look round from distance. Rather than proving which impression was true, skeptics used such examples to argue that since no criterion reliably determines which sense-report accords with reality, the wise person should withhold assent from all dogmatic claims and find tranquility in this equipoise.

Where this idea shows up

9 Greek sources

Where to read it