This document discusses three ancient literary critics - Horace, Longinus, and Plotinus. It summarizes their key ideas and contributions to literary criticism. Horace established practical guidelines for writing and emphasized imitation of classical authors. Longinus defined the sublime as inspiring great thoughts in readers. Its elements include noble themes and diction. For Longinus, a classic text achieves the sublime. Plotinus expanded on Plato's ideas of forms of existence like matter, soul, and intelligence. His philosophy influenced later critics like Augustine and American transcendentalists.