Kenneth Dorter, in a passage-by-passage analysis, traces Plato's depiction of how the most basic forms of human functioning and social justice contain the seed of their evolution into increasingly complex structures, as well as the seed of their degeneration. Dorter also examines Plato's tendency to begin an investigation with models based on rigid distinctions for the sake of clarity, which are subsequently transformed into more fluid conceptions that no longer sacrifice complexity and subtlety for clarity. It is the author's claim that virtually every positive doctrine put forth in the dialogue is problematized somewhere else in the dialogue. This accounts for the apparent incoherence among various parts of the Republic.