Unknowability, incomprehensibility, originally as a characteristic of all things, according to the ancient Sceptics. Hence also: scepticism, profession of ignorance.
((n.) Incomprehensibility of things; the doctrine held by the
ancient Skeptic philosophers, that human knowledge never amounts to
certainty, but only to probability.)
Origin:
Mid 17th century; earliest use found in Gilbert Watts (d. 1657), Church of England clergyman and translator. From post-classical Latin acatalepsia from Hellenistic Greek ἀκαταληψία impossibility of direct apprehension from ancient Greek ἀκατάληπτος that cannot be reached or touched, in Hellenistic Greek also incomprehensible, not comprehending + -ία; compare -lepsy.