On the Nature of Things is a first-century BC didactic poem by the Roman poet and philosopher Lucretius (c. 99 BC – c. 55 BC). The poem explores Epicurean physics through poetic language and metaphors.

Namely, Lucretius explores the principles of atomism; the nature of the mind and soul; explanations of sensation and thought; the development of the world and its phenomena; and explains a variety of celestial and terrestrial phenomena. The universe described in the poem operates according to these physical principles, guided by fortuna ("chance"), and not the divine intervention of the traditional Roman deities.