For the greater good

"...all the actions of all mankind are done with a view to what they think to be good."

Book 1 of Aristotle's The Politics introduces the polis or "city" as the highest association, one that like any association is formed for some good. Later, in Book 7, Aristotle says what distinguishes the city from the lower-order associations, such as the family or the tribe, is that it is "self-sufficient for the needs of life", and its members therefore become part of something like an organism, and only reach their highest potential as such.

Modern political theorists sometimes point to Thomas Hobbes (1588-1679) as the originator of a "corporeal" concept of the state, as a body that subsumes individuals as members, but something like this already is introduced by Aristotle:

"Thus also the city is prior in nature to the household and to each of us individually. For the whole must necessarily be prior to the part; since when the whole body is destroyed, foot or hand will not exist except in an equivocal sense, like the sense in which one speaks of a hand sculptured in stone as a hand; because a hand in those circumstances will be a hand spoiled, and all things are defined by their function and capacity, so that when they are no longer such as to perform their function they must not be said to be the same things, but to bear their names in an equivocal sense."

Obviously individuals, families, and tribes can survive outside of an urban or purely political framework, and Aristotle doesn't deny that. He is merely speaking of the polis as the highest form, not in terms of scale but in terms of purpose, which he links to self-sufficiency. The image is corporeal, but not dismissive of the individual. The incorporation of the city rather elevates the citizens.

If it is a body as Aristotle describes it, its relative health probably would be measured according to its degree of self-sufficiency and ability to sustain life, which probably includes its ability to control pathogens, cancers, or even hyper-active anti-pathogens. The city is a political animal or at least exhibits political behaviors that ultimately aim at the highest good, which is the preservation of the city in its healthiest state. Even though all actions and associations are thought to be "good" by their individual agents, they are only "good" if they contribute to or do not harm the health and self-sufficiency of that greatest good that Aristotle calls the polis.