However if we look at it in the form of a teacher instructing the student the example holds true. The work of Aristotle is one of the best examples of this, as he was considered the reigning authority on a number of different topics throughout the Middle Age and for some time beyond. In fact Aristotle's definitions of the types of good and bad government are used by almost every single theorist for the next 2000 years.
Government, according to the ancients and their learned disciple Machiavel, the only politician of later ages, is of three kinds: the government of one man, or of the better sort, or of the whole people; which by their more learned names are called monarchy, aristocracy, and democracy.
-The Commonwealth of Oceana.
Thomas Aquinas is another example of a great theorist and intellectual whose ideas have retained their worth down through time.
This cross-pollination of ideas and concepts in political theory also happened within the span of one or two generations, especially in 17th and 18th century Europe. The rise in literacy in this period led to the wide dissemination of new ideas across Britain and the continent, albeit restricted to the educated minority, and groups of intellectuals would engage each other in verbal warfare through private publishings or the scant media of the time. Though often there could be dissension within these groups as well, on some of the finer points of theory, central principles were shared and expounded with what occasionally seemed a religious fervour. This can be seen with ideas introduced by such men as: Harrington, Hobbes, Filmer, Locke, Burke, Bacon, Voltaire, Rousseau, Bentham, and Mill. Men whose writings were used as authorities in numerous political and intellectual debates over the next 100 odd years. Up until this period political theory had been limited, with a few exceptions, to either churchmen, who would have received the teachings of the Ancients at the least, or politicians and statesmen who had to deal with the problems day to day.