Fourth Period: 1848–1871.

§1. In 1848 John Stuart Mill published his Principles of Political Economy, believing that the time had now come when “the field of political economy should be resurveyed in its whole extent.” ¹ For such a task he was better equipped than his predecessors in certain important respects. He had received a very thorough and varied education, though an odd one. ² Moreover, “their most vital fault,” says Marshall of Ricardo and his immediate followers, “was that they did not see how liable to change are the habits and institutions of industry. In particular they did not see that the poverty of the poor is the chief cause of that weakness and inefficiency which are the causes of their poverty ; they had not the faith that modem economists have in the possibility of a vast improvement in the condition of the working classes.” ³ But no such fault can be charged against Mill, who, by 1840, had come to regard “all existing institutions and social arrangements as merely provisional,” ⁴ and whose opinions grew more and more advanced as he grew older.