Plato Just And Unjust

There is no doubt, mMorals and actions are controlled and reprehended by a majority or a society. Hard determinism, the theory that an individual's behavior and morals are strictly based on external factors and society is highly accurate. To clarify, if one acts on his or her moral responsibility similar to the universal ethical principle, it will likely be critiqued and result in mass shaming or even detainment. However in other societies this would've been consummately ethical and just and would result in exaltation and praise. How does one know if a society's actions are moral or not? How does one know if their unjust actions are just? To authentically judge a society one must isolate the just and the unjust. As stated in The Republic by Plato,
Now, if we are to form a real judgment of the life of the just and unjust, we must isolate them; there is no other way and how is the isolation to be affected? I answer: Let the unjust man be entirely unjust, and the just man entirely just; nothing is to be taken away from either of them, and both are to be perfectly furnished for the work of their respective lives. (Plato 214)
The isolation of these two opposing societies will aid one in judgement and display if one society will survive or not. However, what Plato stated above actually occurs normally. In every society, there is a just and unjust, the just are known as prosper while the unjust are known as rebellious. The people following the universal ethics principle often have rebellious behavior which leads to separation and a creation of a new society. New societies stemming from other established societies often have different ethics from the originating society, however their culture will stay similar. As stated by