Sir John Hicks’s ‘IS-LM: an explanation’: a Comment

In his dissection of Keynesianism, Alan Coddington (1976)1 makes his deepest incision between ‘Chapter 12 Keynesianism’ and all other varieties. In this I think he goes to the heart of the matter. The General Theory, I would say, is a harp of many strings, not all of them well-tuned and some mutually most discordant. We may surely say that everything we hear from this instrument must be listened to attentively and critically. Something can be learned from Keynes even when we feel on surest ground in faulting him. He does not ask futile questions, though we may sometimes feel that he pursues his quarry into a deep thicket. Moreover, it will be wasteful and obtuse to carry to an extreme the idea that, in the terms borrowed by Sir Isaiah Berlin from Archilochus, Keynes’s explanation of involuntary unemployment is a hedgehog, and not a fox: The fox knows many things, but the hedgehog knows one big thing.’ The one big thing in Keynes’s ultimate conception is our unknowledge of what will create itself in time-to-come. ‘We simply do not know.’ The author of A Treatise on Probability expressly rejects the notion that probability can turn this unknowledge into its opposite. When we accept this view, the possibility of involuntary unemployment becomes self-evident.