The title is the thesis advanced by Andrew Lilico in this article, from about a month ago, in the Telegraph. In the course of advancing it, here is one thing he says:
…[F]or an orthodox economist the only kind of explanation of any behaviour that counts as an economic explanation is an explanation that makes sense of that behaviour — that shows why the behaviour is rational.
To say that orthodox economic explanations show why behaviour is rational, is, I think, to say that such explanations are correct only if the behaviour they explain is rational. You can’t, after all, correctly show why something is so when it ain’t.
This leads to oddness when Lilico goes on to say this:
…[T]here is no behaviour that is not irrational.
I’m pretty sure that ‘irrational’ is a way of saying ‘not rational’. And, because I’m into bivalence and all, I’m pretty sure that ‘not not rational’ just means ‘rational’. So I think the sentence is identical in meaning to this one:
There is no behaviour that is rational.
So economists are primarily in the business of showing why behaviour is rational even though no behaviour is rational??? Um… oops? Or have I missed something?