Cleanthes’ “Hymn to Zeus” is both a religious and a philosophical record of the attitudes of ancient Greek thinkers of the early Stoic school. As the only nearly complete piece of early Stoic writing that has survived intact, it offers a unique insight into the Stoic theological and cosmological worldview of the early third century bce. It is remarkable for its ability to straddle multiple purposes. It is at the same time a lyric “hymn,” in the style of the popular prayers of the period, and a philosophical treatise. It also contains divergent and seemingly incongruous ideas: Within its lines, Zeus, ruling god of the Greek pantheon, is depicted as both a conscious, “knowable” god and an impersonal, pantheistic force of nature. This is a theological standpoint particular to Stoicism.