*Who has to ask?
If you, or that 'person' is unable to investigate facts and data to uncover a lie, you (they) shouldn't be asking me such a question. ![Wink ;)](https://forum.luminous-landscape.com/Smileys/default/wink.gif)
If someone lies long enough about having a horse eventually somebody will buy them a saddle. Maybe that's the goal.
Further:
I was addressing your point,
'When we believe in lies, we cannot see the truth', and trying to make the distinction between believing in the 'efficacy of lies', and unwittingly accepting a particular falsehood as a truth.
Lying in some form or another, and to some degree, seems to be deeply embedded in human behaviour, and also in the general process of evolution. Women can use make-up to lie about their appearance. Men sometimes flatter their wife by telling her how beatiful her hair-style is, when he doesn't really believe it.
That famous scientist, Isaac Newton, who created the Theory of Gravity, couldn't explain why the universe was not collapsing on itself if every object exerted a force of attraction on every other object. He assumed, or believed, that all the stars were static, and claimed that it was God who prevented this force of gravitational attraction from causing the universe to collapse. Was this a lie?
Albert Einstein also believed the universe was static when he created his first Theory of Relativity, and added a Cosmological Constant to his equations to make the universe appear static. This is often referred to as Einstein's Greatest Blunder. Was this also a lie?
I think it's quite common for people with some degree of authority to protect, including scientists in various disciplines, to avoid admitting that they 'don't really know', even though it is the truth that they don't really know..
However, it's often not an 'either/or' situation. For example, is exaggeration a form of lying? Most advertisements exaggerate the wonderful properties of the product in the advertisement. Blatant lying is usually illegal in advertisements, but there are various degrees of lying. Don't you agree?
I'm by no means an expert on American politics, so I probably shouldn't comment on Trump. However, I've read a few times that Trump advised Germany, about 4 years ago, that it shouldn't rely upon Russian gas supplies. He was right about that.
![Wink ;)](https://forum.luminous-landscape.com/Smileys/default/wink.gif)