Platonic philosophy (introductory)
Platonic philosophy was the first systematic pursuit of a thorough interpretation of human nature and action. Plato was the first to set philosophy apart from other interpretations of reality (poetry, religion, politics). In essence, Plato established philosophy and determined its future course.
The influence of Parmenides and the Pythagoreans is discernible in Plato's philosophy. However, source of his inspiration was the companionship with Socrates. In keeping with his teacher, Plato focuses on man. His aim is to found the rational behaviour, and the moral integrity of man. Platonic philosophy is primarily a moral and political philosophy.
Plato's basic contribution to philosophy is the theory of the Forms. The gist of this theory is that beyond the ever-changing, perceptible reality, there are also some independent, stable, and intelligible entities existing in their own right: the "Forms". The existence and the degree of truth of the sensibles is dependent on their relation with the Forms - they "partake" of the Forms, and they "imitate" the Forms. Men can attain unto the Forms through rigorous education; in this endeavour they find an unexpected ally in the motivational power of love. In essence, the ideal platonic city is a big, organized school where wisdom prevails and allows for the attainment of the skilled citizen unto the Forms.
The Forms uphold Plato's entire interpretation of reality. They are the ground of his ontology, for it is only Forms, and not perceptible beings, that maintain an authentic substance. Only knowledge of the Forms is true knowledge; on the contrary, knowledge of the sensibles is uncertain (it is a "belief" and not truth) because they are subject to constant change. Finally, the Forms are stable, unconditional moral values which can determine the moral conduct of men.