P.S. is a 42-year-old man who has been affected by
paranoid schizophrenia since the age of 20. At the
onset of his psychosis, he was trying in various ways to
compensate for his difficulties in getting in touch with
other people. He had no secure ground to interpret the
others' intentions. He lacked the structure of the rules
of social life and systematically set about searching for
a well-grounded and natural style of behavior. For
instance, he was busy with an ethological study of the
"biological" (i.e., not artificial) foundation of others'
behaviors through a double observation of animal and
human habits. The former was done through television
documentaries, the latter via analyses of human interactions
in public parks. An atrophy in his knowledge of
the "rules of the game" led him to engage in intellectual
investigations and to establish his own "know-how" for
social interactions in a reflective way. – Giovanni Stranghellini, At issue: vulnerability to schizophrenia and lack of common sense (2000)
Consensus omnium, common sense and public opinion all exist as separate tracks through the intellectual history of the West – and each trail can be superimposed upon the other.
Early on, in Klaus Oehler’s definitive essay, Der Consensus Ominium als Kriterium der Wahrheit in der antiken Philosophie (1963), there is a quotation from Hesiod. The line quoted comes from the section of the poem devoted to “Days”, with its sometimes obscure reference to work, luck, gods and the days of the seasons. The line, 760, goes: … and avoid the talk of men. For talk is mischievous, light, and easily raised, but it is hard to undo it. Talk is never completely lost, which has been in the mouths of the many. For talk is itself a God.” Talk, here, is not logos, but pheme – which, as Jenny Strauss Clay points out in Hesiod’s Cosmos, is the antithesis of kleos, that is to say, fame: kleos is to be heard about, pheme is to be talked about.’ This enduring couple still presides, in all their debased divinity, over the newspaper and the news and entertainment channels. They are structured by what is likely, or plausible.
The plausible concerns the heart of Oehler’s theme. As he points out, Plato’s antipathetic stance regarding opinion – endoxe – is countered by Aristotle’s respect for it. “The positive value of generial opinion is, as well, the ground for Aristotle’s preference for commonplaces [Stichwoerter]. It is said that in the peripatetic school, under his direction, a wideranding collection of commonplaces was made.” Furthermore: “… This preference of Aristotle … rested on the materr of fact that in commonplaces the infinitely rich experience of many races was documented in a unique way in brief and trenchant formulas, which is the way the Consensus omnium expressed itself.” 
If the pair pheme/kleos presides over the objects of the news, the commonplace presides over the form. It is the style of the cliché, the proverb, the wisdom of mankind – the conventional wisdom of the moment. The duality of fame and infamy, expressed in cliché, is precisely the form of ‘betise’ that a certain school of modernist writers – Flaubert, Bloy, Peguy, Kraus, Tucholsky, Mencken, Orwell – took as their ultimate enemy, even if for some, the wisdom of mankind was what was traduced in the press, rather than simply represented there.
In Oehler’s account, it was not Aristotle, however, but Cicero who transformed the semiotic of ‘talk”. Before Augustine, Cicero interiorized the commonplace as common sense – equating ‘the agreement of the people” with “a law of nature.” After Cicero, the idea of the universal consent of the people moves into the political order as a legitimizing technique – ironically, according to Oehler, Augustus, who ordered Cicero’s murder, took up his idea of the ‘universal consent of the people’ and made it one of the properties of the emperor.