The TIMAEUS came to have special importance in medieval philosophy. For centuries it was the only text of Plato's available, and then in an incomplete Latin translation with NeoPlatonizing commentary by Chalcidius.

1. The physical world is in constant change: things come to be & perish.

2. Change requires a cause (or reason), in two respects:
   • the existence of a thing requires a cause.
   • the characteristics of a thing point to ("participate in" or "imitate") ideals (forms.)

3. Therefore we can established that a DEMIOURGOS, a sort of divine architect/general contractor/superhero-craftsman, must have fashioned the world out pre-existing matter following the patterns of pre-existing forms.

   Why did he do so? So as not to withhold from other beings the existence he enjoyed. "Being without envy (or jealousy), he desired other things to be as much like him as possible."

4. An implied ontology: three fundamental (kinds of) entities in the universe:
   • souls or minds (NOUS)
   • forms or patterns. (Cp. MENO & PHAEDO)
   • a medium (physical matter)

5. Where does change occur? In space, for which Plato offers three names: place, receptacle, & nurse

   Aristotle posed the question when does the change outlined in the Timaeus occur? This was later interpreted as presaging the Christian view of creation in time.