Roman philosophy hardly knows a more original poet than Lucretius (circa 97-55 BC), who is considered one of the great mediators and thinkers of Greek thought. Drawing on the teachings of Epicurus, he developed a philosophy in his work "On the Nature of Things," which centers around the theory of atoms. From their movements, he derived not only the fine structure of matter but also the composition of the universe and the forms of the soul, mind, and perception. It is a strictly materialistic system, in which there is no room for gods—the world is governed by natural laws. Lucretius, who engaged in sharp polemics against all religion, viewed belief in punishing gods as the main cause of the fear of death, which he attributed to all the misfortunes and evils of humanity. In terms of language, "On the Nature of Things" is also one of the most significant works of Roman literature.