Sir Ken says that “we can’t anticipate what the economy will look like at the end of next week”. You might say that that this is just a little excusable over-statement for rhetorical effect—but I suggest that it is more than that. It represents an important intellectual foundation for the whole of Sir Ken’s position to suggest that no-one really knows anything that is objectively true. And this is not only wrong but it is also corrosive of the whole academic enterprise, which has been so important to the intellectual and economic success of our common culture.