In the last chapter I distinguished and tried to locate two dividing lines: the first is reached when the assumption is made that the state lends itself to investigation only in terms of its historical development, so that the political theorist must adopt the historical method of distinguishing periods in history; the second is reached when the assumption is made that a political theory lends itself to interpretation only in terms of the period of history to which it belongs. In the present chapter, Polybius will turn out to have been the first political theorist who makes the first assumption. Particular interest then will attach to the interpretation of scholars today who make the second assumption and attempt to explain the development of Polybius’s political theory by reference to historical changes which took place during his period.