The word "demiurge" is an English word from demiurgus, a Latinized form of the Greek δημιουργός, dēmiourgos which was originally a common noun meaning "craftsman" or "artisan", but gradually it came to mean "producer" and eventually "creator". The philosophical usage and the proper noun derive from Plato's Timaeus, written c. 360 BC, in which the demiurge is presented as the creator of the universe. This is accordingly the definition of the demiurge in the Platonic (c. 310–90 BC) and Middle Platonic (c. 90 BC – AD 300) philosophical traditions. In the various branches of the Neoplatonic school (third century onwards), the demiurge is the fashioner of the real, perceptible world after the model of the Ideas, but (in most Neoplatonic systems) is still not itself "the One". In the arch-dualist ideology of the various Gnostic systems, the material universe is evil, while the non-material world is good. Accordingly, the demiurge is malevolent, as linked to the material world.