"It was John Maynard Keynes, a man of great intellect but limited knowledge of economic theory, who ultimately succeeded in rehabilitating a view long the preserve of cranks with whom he openly sympathised. He had attempted by a succession of new theories to justify the same, superficially persuasive, intuitive belief that had been held by many practical men before, but that will not withstand rigorous analysis of the price mechanism: just as there cannot be a uniform price for all kinds of labour, an equality of demand and supply for labour in general cannot be secured by managing aggregate demand."