Over time, Mark Blaug became increasingly sceptical of the merits of the approach to the history of economics that we find in his magnum opus, Economic theory in retrospect, first published in 1962, and increasingly leaned to favour 'historical' over 'rational' reconstructions. In this essay, I discuss Blaug's shifting historiographical position, and the changing terms of historiographical debate. I do so against the background of Blaug's personal life history and the increasingly beleaguered position the history of economic thought found itself in after the Second World War. I argue that Blaug never resolved the tensions between historical and rational reconstructions, partly because he never fleshed out a viable notion of historical reconstruction. I trace Blaug's difficulty in doing so to his firm conviction that the history of economics should speak to economists, a conviction clearly present in his 2001 essay: "No history of ideas, please, we're economists".