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 Plato's 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. Plato's 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. The middle phase masterpieces include the Cratylus, Symposium, Phaedo, Republic and perhaps the Phaedrus. In the post-Republic phase we find the Parmenides, Theaetetus, Sophist, Politicus, Timaeus, Philebus and Laws, along with the Critias
The two worlds are different because the one beliefs something that does not exist to be the absolute reality and the reality is considered as an illusion, this is so because they are not blessed to experience the divide light. On the contrary, the other world has experienced the reality. So the different is obvious between those who know and those who don't.
The allegory of the cave is directly connected to his political ideology that those people are suitable for the capacity of the ruler, who have come out of the cave and cast their eyes on a vision of goodness. The divine contemplation forces the enlightened and guided men of society to run the city according to their sublime and high insights.
In his knowledge hierarchy, the philosopher has got a special significance, since they are the one who knows. Thus is born the idea of the "philosopher-king", the wise person who accepts the power bestowed upon him by the people who are wise enough to choose a good master. After many years of years of endeavours, such people would have come to understand the "form of the good" and have become philosopher-kings.
Human desires are perceived to be boundless. These desires create needs, these needs are for the sake of not its ownself, but something else. For example, we desire food because we want to remain active and food but Aristotle argued that there must be something that is desired only for its own sake. This was identified by him as happiness, well-being or flourishing (Greek eudemonia literally "having a good guardian spirit"). When it is asked from the people that "Why do you desire this" and then "Well, why do you desire that" in response