Aristotle wrote that the polis is a koinonia (association) which aims at achieving the common good. Implicit in this is the belief that citizenship, or membership of the polis, is participatory and that it is the duty of the good citizen to take his part in seeking the common benefit and security of the state. But what was best for the state could be variously interpreted and was a point on which citizens could disagree. Public policy – and the popular perception of the common good – could change swiftly and erratically according to the fortunes of the political leaders and their political groups.

The common concern to achieve what is best for the state, Aristotle argues, is grounded in philia, ‘for philia is the motive for social life’, and political relationships were embedded within social relationships. Not only were philia relationships based on utility naturally suited to political contexts, but other more personal relationships, such as kinship and comradeship, could also become politicised.