A number of significant concepts emerge from the analysis the Socratic dialogues.
Metaphysics
The term "Platonism" has come to refer to the denial of the reality of the material. Interestingly, Plato presented a sort of topsy-turvy view of reality. Whereas we are inclined to believe the things which we observe are genuine, Plato argued conversely that this world is merely the transient shadow of the real world which he designates as the world or Ideas or the world of Forms. In the dialogues, Plato placed this conclusion upon the lips of Socrates.
The Theory of Forms
The Theory of Forms reflected Plato's conclusion that the material world is not real but is only a shadow of the real world. The world that we observe is temporary, transient, impermanent, whereas the world of Forms or Ideas is permanent, enduring and eternal.
The world of Forms is the world of invariable generalities and not actually a place where certain spiritual things subsist.
In a sense, the forms of the world of Forms or Ideas are archetypal or abstract representations of the many types and properties of things we see around us in this world.
Epistemology
In the Theaetetus Plato argued that belief is to be distinguished from knowledge on the basis of justification.
In the Sophist, the Statesman, Republic and the Parmenides, Plato associated knowledge with the apprehension of unchanging Forms and their relationship to one another.
In greater detail in the Timaeus, Plato contended that knowledge is always proportionate to the realm from which it is gained by which he intended to say that if one derives their account of something experientially because the world of sense is in flux, the views therein attained will be mere opinions and are therefore unreliable.
Opinions are characterized by a lack of necessity and stability.
On the other hand, if one derives their account of something by way of the non-sensible forms, because these forms are unchanging, so too is the account derived from them and knowledge gained in this fashion is therefore reliable.
The State
Plato argued that societies have a tripartite existence that corresponds to the structure of the individual soul. Plato argued that the individual soul consists of the appetite, spirit, and reason.
In Platonic thought, these stand for different parts of the body and the body parts symbolize the castes of society.
The Productive portion represented the abdomen (Workers). Included in this section are the laborers, carpenters, plumbers, masons, merchants, farmers, ranchers, etc.
These correspond to the "appetite" part of the soul.
The Protective portion represented the chest (the Warriors or Guardians).
These are the adventuresome, strong and brave and are part of the military and correspond to the "spirit" part of the soul.
The Governing portion represented the head (Rulers or Philosopher Kings). This domain included those who are intelligent, rational, self-controlled, in love with wisdom, and suited to making decisions for the community.
These groups correspond to the "reasonable" part of the soul and are very few in number.
