"zoon-politicon" (don't ask me if it's written like that) - means that humans are sociable beings what means that it's just natural for them to live together and build states. Aristoteles says that the whole society is based on this concept. That means a state should should it make possible for everyone to live the principles of virtue. The constitution depends on the way of government and for him the midle between monarchy and democracy (constitunional monarchy) is the best way. Greece was divided in different parts at his time named polis (don't ask me if there's a translation for that). Aristoteles prefered that coz he said that people there feel fine there.

That's all I can tell you about that. But aren't you sure that it's Platon that you want to know something about? I mean Aristoteles never had the chance to test his state in reality, Platon had and he failed hard.