(Greek: Λογγῖνος, Longĩnos) is the conventional name of the author of the treatise, On the Sublime (Περὶ ὕψους, Perì hýpsous), a work which focuses on the effect of good writing.[Sometimes referred to as pseudo-Longinus because his real name is unknown, was a Greek teacher of rhetoric or a literary critic who may have lived in the first or third century AD.