In section 37 of the Mytilenean debate, Cleon states, "a democracy is not capable of ruling an empire" (67). For Thucydides, the point of writing Cleon's speech is to show the incompatibility of the two political systems. While a democracy is concerned about the well being of the city by representing the views of a homogeneous citizenry, an empire is broader in scale and involves multiple cultures. Furthermore, a democracy functions on the ideals of fairness and justice, unlike an empire that flourishes on the basis of strength and the pursuit of self-interest. Hence rises the dilemma, where the city must decide for the culture of its democracy or that of the empire.
In his funeral oration, Pericles says Athens "is called a democracy because it is managed not for a few people, but for the majority" (40). Here, Pericles defines democracy as a political system that functions to benefit the general citizenry as opposed to the few elite. Spoken in context of the funeral oration, he attempts to invigorate the patriotism of the Athenians by implying their city is the best in all of Greece because of its political ideology that gives power to the people. Pericles seems to suggest that Athens' democracy characterizes its greatness, making it fit to rule an empire.
Differing from Pericles' view, the Athenian representatives at Melos justify their empire as a universal phenomenon. They assert "nature always compels gods (we believe) and men (we are certain) to rule over anyone they can control" (106). Likening their actions to the divine, the Athenians describe imperialism as a law of nature that affects both mankind and the heavenly alike. By establishing this similarity, the Athenians make their actions seem less uncompassionate. .
Observing their actions through a somewhat stoic lens, they imply that they are abiding to the workings of the universe and that a thirst for power is an innate quality of human nature.