The philosophers’ agreement at the end of Book IV to discuss the various corrupt forms of government is, however, interrupted by an accusation of laziness.
Thrasymachus voices his dissatisfaction with Socrates who, he says, has purposely avoided speaking of the more practical concerns of the State. The objection blossoms into the section on matrimony. Encompassing matrimony, family, and community, Socrates elucidates his very scientific, very futuristic plan for population control and the right breeding of the human animal.
The strong reproduce more often than the weak. Likewise weak offspring are disposed of or hidden away someplace unnamed. Socrates has bucked two of what he calls three "waves."
The third and greatest is the question of whether their possibility is realizable in any way. Socrates' response is mostly negative.
However, there is one method by which the States they see around them might become ideal States. That is, if philosophers become kings or, more likely, if kings take up the study of philosophy.
Hence the famous term philosopher-kings.
But this in turn begs the query: what is the philosopher?
This leads Socrates into another complicated idea, an inchoate version of the Theory of Forms. Manifestations, appearances, likenesses, opinions‹none of them are Reality; they are merely shadows.
Only the Forms, the ideals that lie behind are truth. And the philosopher seeks above all else knowledge of these Forms.
