Cleanthes preserved and developed early Stoicism, especially its religious cosmology, in which Zeus names the rational and providential order pervading the world.
Intellectual setting
Accounts portray Cleanthes as Zeno's student and successor during the formative decades when Stoicism was becoming a major Hellenistic school.
Key ideas
Hymn to Zeus
The surviving hymn addresses Zeus as the rational law through which the cosmos is ordered.
Stoic continuity
As Zeno's successor, Cleanthes maintained the school while articulating its theological and ethical language.
Legacy
His hymn gave later readers a compact expression of Stoic providence and the aspiration to align human reason with cosmic reason.