I see Plato’s book, Republic, as logic-based epistemology applied to political philosophy. Anyway, that would be my claim in my undergraduate Philosophy 101 essay on Plato.
The conceptual range of “logic” and “epistemology” and “politics” in Plato’s Republic is that of a sophisticated and prosperous well-educated aristocrat of late 5th Century and early 4th Century BCE Athenian-Greek society. That conceptual range is free of prehistoric animism, and Asiatic and Celtic mysticism; it is solidly materialistic and absent any “depth psychology” of the type that would be popularized by Sigmund Freud and C. G. Jung (the psychology of the “unconscious”). That conceptual range is also absent any qualms about hierarchical society structured on hereditarily-conferred class-based social status and functional roles, and which includes slavery.
So it is easy to see Plato’s Republic as the stone at the center of the plump fruit that is Western Philosophy with its inner flesh of Christian mythology and irrationality — which appropriated, subsumed, reformulated and blended prior pagan myths and mysticisms to serve the needs of temporal political hierarchy — its middle layer of Renaissance and Enlightenment rationalism, and with its outer flesh and skin covering as later envelopments by early 19th Century Romanticism — emotionalism — and late 19th Century Nietzschean anti-religious intellectualism, Freudian-Jungian depth psychology as a substitute for discredited and discarded Christian metaphysics, and the proletarian-socialist consciousness engendered by industrialization.
As 20th and 21st Century individuals, parts of each of us live in various prior periods of the development of Western Consciousness, depending on the particulars of the arcs of our personal psychological, family, ethnic, cultural, educational, economic and political situations.
The slow inter-bleeding of Eastern and Western Thought, at least since the 19th century, has somewhat diluted both, more fundamentally in the East that has become quite enthusiastically capitalist since the 20th Century, than in the West that has added a minor flavoring of Eastern philosophy into the self-absorbed and self-indulgent aspects of its materialistic consumerist obsessiveness.
In his book, Republic, Plato lays out his political philosophy for the establishment and maintenance of a stable, well-ordered and just society. In his time societies were city-states, like Athens in the time of Socrates, Plato and Diogenes. The essential element of Plato’s scheme is the “guidance” of the city — “governing” is too strongly “micro-management” of a word — by a class of “guardians” who were carefully selected and trained from youth for the task, and who were wholly devoted to it for their lifetimes: basically philosopher-guru-priests.
However, I note that the viability of Plato’s political formulation for the construction and operation of just societies rests primarily on the incorruptible moral character of its central and guiding personnel, the guardians, and secondarily on the reasonably stable decency of behavior of the citizens: that is to say, their morality.
Please note that by “moral” I do not at all mean “religious”; there is no functional correlation between the two (and in my view more likely an anti-correlation).
At least since the end of the Neolithic, the idea developed that a stable, well-ordered society (whether just or unjust, but always to the liking of its rulers) could be established solely by political means, such as in: monarchies, parliamentary democracies, socialist and communists states (most pointedly those sharply Marxist materialist), and dictatorships (whether purely materialistic or theocratic).
By political I mean social arrangements for societal management that are constructions external to the individual person. Note that such political structures can include elements of physical compulsion on individual behavior, and elements of thought-control by indoctrination and propaganda to capture, shape and distort individual thought, and that such political structures will still be external to the individual as a moral being.
So, I do not believe it is possible to ensure the stable continuation of any momentarily just society, whatever its political structure, solely on the basis of the forced maintenance of that political structure, nor solely on the basis of a change of political structure whether that change is reformist or revolutionary. Justice as societal stability requires a taproot into incorruptible moral character by a majority of the citizens. Justice is good politics and good political structure, and is a natural outgrowth of good and intelligent morality, which in turn is individually personified as character.
Given the above, I believe that any social movement aiming to “permanently” evolve, reform or revolutionize a society in need of anything from improvement to drastic change in order to make it universally just, has to base its efforts on developing the moral character of its movement adherents and the mass of citizens it wishes to convince, for lifetime incorruptibility. Here, we have faith that a society with a majority of its citizens being of incorruptible moral character will ensure the continuation of such in succeeding generations, by the operation of its educational systems.
Of course any serious movement for social change will act politically whenever it can to counter existing injustices and respond to humanitarian emergencies. But it must never lose sight of its chronic fundamental task — instilling ethics — regardless of the frequency and variety of crisis flare-ups it reacts to during the daily spectacle.
Yes, this prescription for engineering permanent social change for the better is an idealization that may seem impossible to implement, as witnessed by the history of human civilization, but I think it is nevertheless true and has been the most powerful force that has helped bring about whatever degree of decency any of our human societies possesses today.