In the Platonic, Neopythagorean, Middle Platonic, and Neoplatonic schools of philosophy, the demiurge is an artisan-like figure responsible for fashioning and maintaining the physical universe. The Gnostics adopted the term demiurge. Although a fashioner, the demiurge is not necessarily the same as the creator figure in the monotheistic sense, because the demiurge itself and the material from which the demiurge fashions the universe are both considered consequences of something else. Depending on the system, they may be considered either uncreated and eternal or the product of some other entity.
A lion-faced, serpentine deity found on a Gnostic gem in Bernard de Montfaucon's L'antiquité expliquée et représentée en figures may be a depiction of the Demiurge.
Drawing of the lion-headed figure found at the Mithraeum of C. Valerius Heracles and sons, dedicated 190 CE at Ostia Antica, Italy (CIMRM 312).
Neoplatonism is a version of Platonic philosophy that emerged in the 3rd century AD against the background of Hellenistic philosophy and religion. The term does not encapsulate a set of ideas as much as a series of thinkers. Among the common ideas it maintains is monism, the doctrine that all of reality can be derived from a single principle, "the One".
Presumed depiction of Plotinus and his disciples on a Roman sarcophagus in the Museo Gregoriano Profano, Vatican Museums, Rome