title_body: Are there conlangs which compel their users to speak with honesty? George Orwell's novel 1984 introduced us to
  Newspeak,
  a language devised by authorities to be entirely misleading.
  
  Languages that attempt to guide knowledge have been termed Orwellian
  and, more technically, relativistic or Sapir-Whorf.
  
  Any examples of languages that are opposite of Newspeak,
  compelled to be genuine?
upvoted_answer: I don't think that languages, whether natural or constructed, have this power.
  
  The fact is that there are numerous ways to be deceptive. You can straight out lie, you can speak as if there is uncertainty when really there is not, you can be deceptive through what you don't say, and you can be deceptive by saying true facts that are not actually strictly relevant, something called "paltering".
  
  Like most linguists now, I think that the weak Sapir–Whorf hypothesis, that our language influences our thoughts and decisions, is surely true, but I am sceptical about the strong version, that language completely determines and limits our thought categories. Either way, I don't think it's really relevant to the aspect of human psychology which makes deception possible. Lying through omission or distraction is possible because our minds can generate multiple possible statements to make to others, each disclosing a different level of truth, but none of us are compelled to speak every thought that enters our minds.
  
  Perhaps someone has invented an alien species with an alien psychology and an alien language to speak, and maybe in their universe their language does compel them to speak honestly. But what would it mean to prove such a thing, and how could anyone else present an argument to refute their claims? So for humans I say the answer is no, and for fictional creatures it's not a useful question for us to ask.