It is in people's nature to live together, to form social groups and ultimately to form a political community, in ancient Greek times known as a polis.1 However, according to Aristotle, living in a polis does not necessarily mean that one also is a full citizen of that polis and so the question arises; "Who should be able to be a citizen in a polis?" Following Aristotle's thoughts on the subject this essay will show what he thinks of citizenship, who (and who not) is eligible for citizenship, terms & conditions of citizenship and in conclusion I will form an opinion on Aristotle's points of view on this subject.
Aristotle was a frequent traveller, and this experience taught him that there was no universal rule on citizenship. He states; "it often happens that one who is a citizen in a democracy is not a citizen in an oligarchy." However, Aristotle defined a common denominator for citizenship. Citizens are persons who perform public tasks. Who are different from other inhabitants of the polis because they are allowed to take part in passing judgment and holding office.2 In stating 'holding office' Aristotle is broadminded. He does not narrow it down to what we might call civil servants, but also includes people who have to perform jury duties, take part in assemblies etcetera. According to Aristotle his definition of citizenship works best in a democracy because that form of constitution offers enough public functions, and thus enough chances, to become a citizen.
Aristotle realizes very well that although this point of view would work very well in his home polis of Athens, it would not work at all in e.g. Sparta where taking part in public office had a more ad hoc character. To overcome this Aristotle changes his basic rules. Citizens don't have to perform public tasks anymore but; "as soon as a man becomes entitled to share in deliberative or judicial office he is thereby citizen of that city, and a city, in its simplest terms, is a body of such people adequate in number for achieving a self-sufficient existence.