The Demiurge appears in Plato’s Timaeus as a human craftsman ([correction]demos = common people; ergo = work; hence a human craftsman). But it is interesting to note what David Hume does to the demiurge. Hume in Dialogues, through his character Philo, attacks the notion that there might be an analogy between the designer of nature and human intelligence. However, in section VII, Philo calls for a belief in copulation and generation from Hesiod’s Theogeny and Plato’s Timaeus. In other words, Hume quotes the Timaeus, in which the demiurge appears, to attack the idea that there is an analogy to human intelligence from design in nature – an apparent contradiction. David Sedley comments in Creationism and its critics in Antiquity that the demiurge should be interpreted metaphorically and gives the game away – as does Erasmus Darwin in Zoonomia.
“The late Mr. David Hume, in his posthumous works [Dialogues], places the powers of generation much above those of our boasted reason; and adds, that reason can only make a machine, as a clock or a ship, but the power of generation makes the maker of the machine; and probably from having observed, that the greatest  part of the earth has been formed out of organic recrements; as the immense beds of limestone, chalk, marble, from the shells of fish; and the extensive provinces of clay, sandstone, ironstone, coals, from decomposed vegetables; all which have been first produced by generation, or by the secretions or organic life; he concludes that the world itself might have been generated, rather than created; that is, it might have been gradually produced from very small beginnings, increasing by the activity of its inherent principles, rather than by a sudden evolution of the whole by Almighty fiat. What a magnificent idea of the infinite power of THE GREAT ARCHITECT! THE CAUSE OF CAUSES! PARENT OF PARENTS! ENS ENTIUM!” E.Darwin – Zoonomia.
In other words, Plato’s demiurge should be interpreted metaphorically as a ‘power of generation’ at work in nature enacting gradual change over long periods of time. Plato also had a Metaphor of the Sun in the Republic, where the sun was a source of generation – the sun being a metaphor for a spiritual reality as a light bearer. Yes Plato was apparently influenced by the cult of Mithras.
To sum up, I think Darwinian evolution is in fact based on a metaphorical reading of Plato’s Timaeus, and Hesiod’s Theogeny. Although Charles Darwin took the pagan imagery out of the family theory, the paganism is latent in the ambiguity that exists in the concept of nature between Plato and Epicurus. Those who think the intelligent designer might be Plato’s demiurge need to consider how Plato should be interpreted. For those of us who are Christian supporters of the design argument, the battleground is still between Philo and Cleanthes, whether there really is an analogy to human intelligence, or whether design might arise through some blind pagan force of nature, or through purely random events.