How did ancient skepticism challenge claims of certain medical knowledge?

Ancient skepticism challenged claims of certain medical knowledge by questioning the ability of practitioners to definitively identify the causes or cures of diseases. This movement, known as medical skepticism, was closely linked to the development of Pyrrhonism in Alexandria.12

The Pyrrhonist approach, famously articulated by the physician and philosopher Sextus Empiricus, utilized a series of tropes—or modes of argument—to challenge dogmatic claims to knowledge. These arguments highlighted the variability of human and animal perceptions, which made it difficult to establish reliable criteria for truth. By demonstrating that any attempt to verify a medical theory or criterion would lead to either an infinite regress or circular reasoning, skeptics aimed to induce epochē, or the suspension of judgment.23

Rather than seeking absolute theoretical certainty, these skeptics advocated for living undogmatically according to appearances, customs, and natural inclinations to achieve ataraxia (unperturbability). This stance stood in contrast to medical "dogmatists" who sought to uncover hidden mechanisms of illness, emphasizing instead a practical reliance on observed clinical effectiveness.241