Criticism involves the formation of a judgement towards something that the critic believes could have been done or made otherwise (for better or worse). Thus, criticism presupposes not only a strong divide between subject (the critic) and object (the criticized) but also that the subject has an interest in the object even though she was not directly involved in constructing it. In this respect, criticism is always a constructive enterprise that occurs against a value consensus (see consensus versus dissent). Thus, in ancient Athens, the kritik was the judge whose verdict converted a private dispute into a public matter, a res publica, from which everyone may learn and the polity grow stronger. This role is akin to that of the interested non-participant in knowledge production. (See normativity.)

A key social condition for criticism – one difficult to establish and maintain – is the mutual recognition of critic and criticized. Criticism is impossible when the criticized is not, in some sense, accountable to the critic. (See rationality.) Historically, as Habermas has stressed, this condition has been tied to the fate of the public sphere, especially its sense of mutual peer accountability. (See free enquiry.) It is easy to forget in these postmodern times (see postmodernism) that being ignored is not a subtle form of criticism, but its very antithesis. The Athenian kritik always judged an equal in public, and hence in a state of mutual accountability.