The smartest economists have always understood the importance of such intellectual maypole dancing. John Stuart Mill believed that his 1848 book Principles of Political Economy was acclaimed in his own day because it treated political economy, ‘not as a thing in itself, but as a fragment of a greater whole; a branch of social philosophy, so interlinked with all the other branches that its conclusions, even in its own peculiar province, are only true conditionally, subject to interference and counteraction from causes not directly within its scope’.
