Cant: Current jargon and clichés of some society or social group.
1. The majority of the people speaks and reasons in terms of the jargon and clichés of the day, that embody the popular illusions and fallacies of the day, and partially pretend and partially believe that these are true and important, and how one should speak and think.
What Byron said about England holds in general for any society, for reasons explained below:
"The grand primum mobile of England is cant; cant political, cant poetical, cant religious, cant moral, but always cant, multiplied through all the varieties of life."
Dr. Johnson had the following realistic counsel, seeing that it may be difficult not to speak cant:
"Sir, clear your mind of cant!".
Those who cannot give clear evidence that they can do so, have given clear evidence they cannot think rationally.
2. There are two main reasons for its prevalence in society: stupidity and conformism. Especially the last is interesting: People indulge in cant to indicate they belong and wish to belong. When they offer a cant phrase, the subtext is: Let you and me pretend we are part of the same society by exchanging some of its current cant.
It should be noted that this may be considered as a kind of acting as if and playing, but that it differs from the same in children, in that children know they act as if and play, say, cowboys and indians, and know what it is to act normal.
But there is usually, for ordinary people, concerning most subjects, nothing but cant: They don't have anything better or different in the situation and about the subject than the cant they offer; what they offer is the normal cant of the day in their group; they offer it to signify they belong socially to that group of Us, like dogs and hyena's offer their group-smell; and they know they pretend, but because they don't have any alternative but pretending and because what they pretend is what is currently in their social environment the fashion, they don't want to admit they pretend, except if such an admission is a piece of common cant as well (as may happen: "Poor Humble Sinner That I Am").
To be a phoney, that is to be a well-behaved canting conformist, is the only way ordinary people can be social, in an ordinary public of their social equals or superiors. Moreover, and conversely: Ordinary people understand being social as being a phoney, as acting as if, as pretending and keeping up each other's pretences.
This is also part of the secret of role-models, advertising etc. - these encode and communicate the "How Things Should Be And Seen To Be" of common folks, that teach how one should appear to be in kinds of situations to be counted by all that belong to We that one is one of Us.
For ordinary folks, including their politicians and priests, being social is being a public phoney and consists mostly in conspicuous canting, to show one belongs and knows what it seems like to be one of Us, and to demonstrate who keeps up the proper pretences.
3. Next, there is another side to this canting conformism: Ordinary people ordinarily know they cant, but they often also generate a kind of emotion belonging to the cant. These emotions too are cant, or make-belief, but they nevertheless motivate. One good example is wherever a political or religious leader speeches publicly to some of his followers: For them it is good form to act as if they are enthused and instructed, and to act as if they feel so. And indeed, motivated as they are then they may go into some war.
The psychology is somewhat like this: "I know I am pretending, but the end I am pretending for is - I maintain - a noble one, and thus my pretending is noble and must be taken serious, and indeed honored. And anyway, the majority of the We I belong to do so too and feel just the same - so I would be considered crazy if I would not be like one of Us." ("If in Rome, do as the Romans do" - if among cannibals do as the cannibals do.)
4. And here is an analysis in LPA of canting and its uses:
(1) aD(F'a) & aB(F'a --> Fa)
(2) aC(Fa) & aD(bBFa --> ~bA~F'a)
To start with, one desires to be in state F' and believes that if one is, then one is in state F. Therefore, one tries to be in state F and desires everyone who believes one is, not to assert that one is not in state F'.
In short, this is exactly like the case of the emperor without clothes, in principle. Note aD(bBFa --> ~bA~F'a) IFF aD~(bBFa & ~bA~F'a), and that what a desires of b is external conformism.
In the above formulas, the F represents cant, and the F' is a supposedly desirable state of a - that often is ideological and about leaders: Say a's beliefs that Marx was a great genius who discovered the laws of necessary historical development. The corresponding F might be: a is a tireless worker for the Party and often tells his comrades how great a man Comrade Stalin is. (I take an example of the past to make things clearer.)
Note also that a much stronger form than (2) often does not obtain with real cant:
(3) aC(Fa) & aD(bBFa --> bBF'a)
This is deception, but the point of cant and social hypocrisy is not deceiving each other but keeping up the pretences: Part of the game is that the others should not assert publicly that they are not deceived, whatever they really think.
Furthermore, the canting is, for ordinary minds, truly social behavior, and rather like étiquette and polite manners: Well-behaved ordinary minds speak the cant of their day, with pride, and out of conformism, and use their canting to indicate they want to be counted as well-behaved conformist ordinary minds - which then is indeed what they are, whatever they really believe about the cant by which they prove this.
Finally, cant has the pleasant property, for ordinary minds, that one is not contradicted, by ordinary minds: To contradict the common cant of the day is to be socially deviant, improper or gauche, and is definitely bad form, according to the ordinary conformist's understanding and sense of moral proprieties. For the ordinary mind to deny or question the current cant is immoral and improper.