This chapter outlines Plato’s metaphysics of artefacts on the basis of his explicit references to Ideas of artefacts in the Cratylus and Republic X, his discussion of the eidetic cosmos presented in the Parmenides and the description of the material world as a product of the divine artisan in the Timaeus. The second section presents the shortcomings of Plato’s account detected by Aristotle and addressed through artefacts: these are Plato’s failure to recognise final causes and the concept of imitation. The third section outlines the metaphysical intuitions upon which Aristotle builds by taking artefacts into account. The roots of certain metaphysical problems are not explicitly identified as Platonic, but they are arguably to be found in the Platonic corpus. These problems concern the range of things that have a form, the separation between axiology and metaphysics, the concept of real kinds and the relation between parts and whole.