I was reading Republic, and when Plato finally "finds" justice in the city, he defines it as a kind of "doing one's own work", which to me implies also the necessity of finding a certain satisfaction in said work. In Judaism, when the question is asked "Who is he who is rich?" the answer given is "השמח בחלקו" or "he who is happy with his lot" (Pirkei Avot 4:1). The concepts seem somewhat similar to me. Thus both discuss how one crucial thing (although they fit it in differently) is to find your rightful (in an emotional sense) place in life. Is there anything to this theory, or am I misunderstanding Plato?
One quick thought here is that there is another sense to the stratification in the Republic; it is a principle of responsibility-separation not just used to ordain life-tasks to individuals, but also to ensure the separation of duties and scope for different governmental institutions. This is basically the sense of the Platonic critique of democracy; that its "unnecessary desires" corrupt the order (divisions) necessary for justice (harmony). A rough rendering here might be that the legislature should not do the work of the judiciary.