Richard Rorty and others articulated a powerful criticism of the idea that for a sentence to be true means that it corresponds to a free-standing fact. For one thing, it’s not clear — how does a sentence — marks on paper or events in a brain — correspond to a fact — the moon going around the Earth? For another it seems to ignore how sentences are a part of our lives, intertwined with our needs and purposes, our bodies, and our environment.
Rorty (drawing on a bunch of other philosophers) put forward the idea that sentences are like tools. The sentence “water quenches thirst” is true because it is part of a whole toolchest for running our lives. It helps us get things done — for example it helps us quench our thirst. We should view the relationship of scientific vocabulary — “H20 quenches thirst” and regular vocabulary “water quenches thirst” along the lines of how we view the relationship of mechanical jackhammers and plain ordinary hammers. The science is more powerful and has wider application, but in its own place “water quenches thirst” is true.
If that’s the case what should we say about lies? For example suppose somebody says “Pepsi quenches thirst better than water”. That’s not true. But it has a purpose obviously — its purpose is to sell Pepsi.
I think lies for the pragmatist (or deconstructionist) are false tools offered to us with malicious intent. If there is a hammering contest and you give me a hammer that is deliberately misweighted, you are like the liar proffering “Pepsi quenches thirst better than water” for your own nefarious ends.
Like true sentences lies can come interwoven with other malicious practices. The person selling a bogus cure for diabetes could also throw in for free a bogus blood sugar tester which says that the diabetes cure is working, even though it isn’t. The sellers of Pepsi can mount a whole political campaign (they did) saying fat makes us ill, not sugar.
This is in my view what is going down with the current administration’s lying.
An interesting question is are they lying to themselves? Some are, I’m sure. President Trump I’d imagine looked out at a huge crowd, thought it was really huge, and couldn’t bear the possibility that it wasn’t the biggest ever, so he told himself a lie, and then reinforced the lie with a story about how the media who told the truth must be lying.
Trumps anger with the media and his desire to call them a pack of liars is understandable; I often feel the same thing about my bathroom scale.