2. According to Aristotle, polity is the third best regime. What is polity, and what factor(s) justify Aristotle' ranking it neither higher nor lower than he does?
Polity is the third best of the better kinds of regimes, according to Aristotle, ranking below monarchy and aristocracy. Below it rank the three descriptions of corrupted forms of regime, with democracy being described as the bad form of the polity regime, and tyranny and oligarchy the bad forms of kingship and aristocracy, respectively. Polity is the name Aristotle assigns to a regime that is governed by a civic body, or constitution, such that the masses are meant govern, like the monarchy and aristocracy according to the "common interest" (1279a25)--specifically, not according to the factional preferences of the body of governance.
What is central to the concept of governance, in Aristotle's formulation, is that it be disinterested and impartial, always looking to the common good of the government and governed alike and not to the benefit of those controlling the government. The reason that Aristotle ranks it behind monarchy and aristocracy owes something to the class-riven, slaveholding structure of ancient Greece, which Aristotle seems to assume as a given of social organization. What has to be understood is that Aristotle does not question the justice of slavery or for that matter class as social institution but instead assumes that they are permanent fixtures of human experience. For example, he remarks in passing that interests of "the natural master and the natural slave" might reasonably intersect in a good society (1278b30). The present point is that Aristotle's description of political organization is presumptively exclusionary. The idea of citizenship status for slaves, laborers (perhaps the unskilled but freeborn workers), or mechanics (perhaps skilled laborers or craftsmen) is disparaged (1278a13), although Aristotle acknowledges that a rich mechanic mig...