Metaphysics is the branch of philosophy whose primary focus is to respond to the enquiry ‘What is there?’ In a collection of his works, the most detailed treatise on the general topic of things ta phusika (from which English derives ‘physics’). Since the Greek for ‘after’ is meta, this treatise is titled ‘Metaphysics’. The metaphysics takes into account the material as well as immaterial objects like, property, subject, change, being essentially or accidentally.
Three ancestors highly inspired Platos thoughts on metaphysics and epistemology, Heraclitus (c. 540 B.C.-480-70), Parmenides (c.515 B.C.-449-40), and Socrates (470 B.C.-399). Only few extracts of the writings of Parmenides and Heraclitus, including some contained in the dialogues of Plato. Socrates did not write anything. Platos work, influenced by that of his teacher is our primary source of evidence for his philosophy. Parmenides argued that there is and could be only one thing, Being. Furthermore, since change implies that something comes into existence from non-existence, nothing can change. This implies that the reality is static.
Plato wrote at different times different dialogues. Usually, his writings is divided into three phases. In the early ‘Socratic’ phase, we find Apology, Crito, Euthyphro, Charmides, Ion, Lysis, Laches, Hippias Minor, Menexenus, Euthydemus and the Protagoras. The Hippias Major, Gorgias and perhaps the Meno belong to the end of this period, maybe with the Gorgias and more likely the Meno verging into the middle phase.