Empire as a subject for philosophy (polis, imperium, cosmopolis)

In order to consider the question of whether empire is a subject for philosophy, I do three things. I sketch an original typology of three types of state, which I call polis, imperium and cosmopolis, in order to show that the second is an important philosophical conception which lies behind the terminology of empire and imperialism. I also consider modern theories of empire and imperialism in order to indicate some of their limitations as theories. And finally I indicate that it is important even for philosophers to recognise that all imperial terminology emerges out of a very complicated history in which the concept of imperium has been extended and distorted in meaning, so that, at best, any good theory of empire or imperialism can only be some sort of recapitulation of that history. Neither the second nor the third of these claims undermines the claim of imperium to be a concept of the state which is of great political and philosophical significance.