Following Pietro Pomponazzi and Simone Porzio in their interpretation of the Aristotelian texts and the commentary thereon by Alexander of Aphrodisias, Vanini denied the immortality of the soul and attacked the Aristotelian cosmos-view. Like Bruno, he denied the difference between the everyday world and the celestial world, saying that both are composed of the same corruptible material. He disputed, in the physical and biological world, finality and the hylomorphic Aristotelian doctrine, and, reconnecting Epicureanism with Lucretius, prepared a new mechanistic-materialistic description of the universe where bodies are likened to a watch, and conceived a first form of universal transformation of living species. He agreed with the Aristotelian eternity of the world, especially considering the temporal aspect, but affirmed the rotation of the earth and appeared to reject the Ptolemaic system in favour of the heliocentric/Copernican system.