All human beings who possess a language have opinions on anything they have experienced, through direct sensory contact or through the words conveyed by others. Apparently, there may be only a short step from individual opinion to aggregates of opinion. But historically, the step is quite a giant one. And it is a matter of conceptual clarification and empirical observation to assess whether and how opinions perform a public function.

Public opinion requires that the public becomes both the subject and the object of shared beliefs. It grows out of major changes in the structure of the governmental apparatus constituting the public sphere, as well as in the rising of a new class of people determined to influence the public sphere with criticism and open-minded discussion. However, individual opinions, while a prerequisite for the forming of an informed public, can choose other channels of expression, the most relevant being electoral representation.