On the Heavens
On the Heavens (Greek: Περὶ οὐρανοῦ; Latin: De Caelo or De Caelo et Mundo) is Aristotle's chief cosmological treatise: written in 350 BC, it contains his astronomical theory and his ideas on the concrete workings of the terrestrial world. It should not be confused with the spurious work On the Universe (De Mundo, also known as On the Cosmos). This work is significant as one of the defining pillars of the Aristotelian worldview, a school of philosophy that dominated intellectual thinking for almost two millennia. Similarly, this work and others by Aristotle were important seminal works from which much of scholasticism was derived.