Acatalepsy

{{Short description|Concept of human knowledge in philosophy}}

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Acatalepsy (from the Greek {{lang|grc|α̉-}} {{gloss|privative}} and {{lang|grc|καταλαμβάνειν}} {{gloss|to seize}}), in philosophy, is incomprehensibleness, or the impossibility of comprehending or conceiving some{{Cyclopaedia 1728}} or all things. The doctrine held by the ancient Skeptic philosophers, that human knowledge never amounts to certainty, but only to probability.{{cite dictionary |title=acatalepsy |dictionary=Webster's Revised Unabridged Dictionary |year=1913 }}

The Pyrrhonians attempted to show, while Academic skeptics of the Platonic Academy asserted an absolute acatalepsia; all human science or knowledge, according to them, went no further than to appearances and verisimilitude. It is the antithesis of the Stoic doctrine of katalepsis or Apprehension.{{cite book |author-link=George Henry Lewes |first=George Henry |last=Lewes |year=1863 |title=The biographical history of philosophy |volume=1 |page=297}} According to the Stoics, katalepsis was true perception, but to the Skeptics, all perceptions were acataleptic, i.e. bear no conformity to the objects perceived, or, if they did bear any conformity, it could never be known.