In philosophy, an aporia is a philosophical puzzle or a seemingly irresoluble impasse in an inquiry, often arising as a result of equally plausible yet inconsistent premises, i.e., a paradox.
In Plato's Meno (84a-c), Socrates describes the purgative effect of reducing someone to aporia: it shows someone who merely thought he knew something that he does not in fact know it and instills in him a desire to investigate it.
In "Aporetics: Rational Deliberation in the Face of Inconsistency" (2009), Nicholas Rescher is concerned with the methods in which an aporia, or "apory", is intellectually processed and resolved.
In his Preface, Rescher identifies the work as an attempt to "synthesize and systematize an aporetic procedure for dealing with information overload (of 'cognitive dissonance', as it is sometimes called)" (ix).
Rescher further introduces his specific study of the apory by qualifying the term as "a group of individually plausible but collectively incompatible theses", a designation he illustrates with the following syllogism or "cluster of contentions": 1.
Shall I relate how your father Tromes was a slave in the house of Elpias, who kept an elementary school near the Temple of Theseus, and how he wore shackles on his legs and a timber collar round his neck?
Or how your mother practised daylight nuptials in an outhouse next door to Heros the bone-setter, and so brought you up to act in tableaux vivants and to excel in minor parts on the stage?