One of the ways in which oppression and tyranny betray their existence, at least for the least corrupt and historically short-sighted, is through the style and content of the language that is used to legitimate its existence.
In terms of style, oppressors employ a coded language of semantic deception, often qualifying as Orwellian newspeak. Such abuses of language range widely over the historical landscape of oppression. It is both employed ad captandum vulgus (to win over the minds of the masses, whose moral pretensions would be offended if the torture, exclusion and victimization society doesn't seem able to cope without were called by their proper names) and in order to protect its practitioners from guilt feelings. The oppressor always makes language an accessory to his crimes, and is outraged by the lese majeste of those people who refuse to accept his or her abuses of language. Sadly, in the masses, who are ever receptive to oppression's wiles and casuistries, oppression has another reliable accomplice, who'll always trust the word of the powerful over the powerless, whose gullibilty is limitless when confronted with the accoutrements that signal power and authority, as countless social-psychological experiments have demonstrated.
Another marker is the rhetoric of paternalism and protectionism. Patriarchal oppression, racial oppression, religious oppression, political and psychiatric oppression have all been characterized by the stubborn insistence by the oppressor that their victims and subjects are like little children to whom the oppressor must act in a parental capacity in relation to them.
Then there is the appeal to necessity. One of the reasons why chattel slavery lasted so long was because it was taboo to question the social necessity of the institution. The same applies today with psychiatric slavery. In the former case, the slave was seen as a savage, who would quickly degenerate into lunacy and savagery if not kept in what was deemed his natural state, whose subjugation checked his base instincts, and on top of this it was also seen as an economic necessity. The psychiatric slave must also be enslaved, because, as received and authoritative opinion would have it, in his psychotic, irrational state, he is wild and unpredictable, and he needs the sane psychiatrist to dominate him. In the former case, we have unashamed white supremacism; in the latter, psychiatric supremacism.