The Republic is Plato's most famous work and one of the seminal texts of Western philosophy and politics. The characters in this Socratic dialogue - including Socrates himself - discuss whether the just or unjust man is happier. They are the philosopher-kings of imagined cities and they also discuss the nature of philosophy and the soul among other things.

According to Wikipedia: "Of The Social Contract, Or Principles of Political Right (Du contrat social ou Principes du droit politique; 1762) by Jean-Jacques Rousseau is a book in which Rousseau theorized about the best way to establish a political community in the face of the problems of commercial society, which he had already identified in his Discourse on Inequality (1754). The Social Contract helped inspire political reforms or revolutions in