Abstract: This work addresses the following question: What would be the consequence of allowing a representative of ancient Pyrrhonian scepticism to become a party to contemporary debates in theory of knowledge? The conclusion of this work is that most of our contemporary epistemologists would fare badly in this encounter.Part 1 concerns the analysis of knowledge claims. It defends the almost universally rejected view that knowledge is simply justified true belief. This analysis is generally thought to be untenable because it yields skepticism or Gettier problems (or both). In response, it is argued that everyday knowledge claims are protected from both difficulties by placing limits on the level of scrutiny, that is, limits are placed on the range of possible defeators that are taken seriously. Conversely, when these constraints are set aside, as epistemologists often do, skepticism and Gettier problems understandably arise. Three chapters are dedicated to examining and criticizing alternative analyses of knowledge claims: various fourth-clause analyses, externalist analyses, and subjunctive (possible-world) analyses.Part 2 concerns theories of justification. It presents a confrontation between Agrippa's Five Modes Leading to the Suspension of Belief (as found in Sextus Empiricus's Outlines of Pyrrhonism) and three contemporary theories of justification: Chisholm's foundationalist theory, BonJour's internal coherentism, and Davidson's external coherentism. The conclusion of this examination is that none of these accounts of justification makes serious headway in responding to Agrippa's Five Modes.

Keywords: Agrippa, Laurence BonJour, Roderick Chisholm, coherentism, Donald Davidson, foundationalism, Gettier problem, justification, knowledge, Pyrrhonism, Sextus Empiricus, skepticism