Acatalepsy

Acatalepsy (from the Greek α̉-, privative, and καταλαμβάνειν, to seize), in philosophy, is incomprehensibleness, or the impossibility of comprehending or conceiving a thing. Acatalepsy is the incomprehensibility of all things; the doctrine held by the ancient Skeptic philosophers, that human knowledge never amounts to certainty, but only to probability.