Here, in fact, we have the key to Bentham's character, to its weakness and also to its strength. A philosopher who plunges into the practical affairs of the world without taking human feelings and imagination into account is sure to find himself stumbling about among blocks and blockheads, and tripped up by the ill-will of vested interests; but on the other hand, if he has taken the right direction, his ardent energies have the impetus of some natural force. Bentham's earlier notion had been that political reforms could be introduced like improvements in machinery; you had only to prove the superior utility of your new invention to obtain its adoption by all who were concerned in the business. Latterly he made the surprising discovery that in the public offices, in the Law, and in the Church, the heads of these professions are usually quite satisfied with their own monopolies, are opposed to change, and are always ready with a stock of plausible arguments to show the folly and danger of innovation. If the Utilitarian appeals to facts, common sense, and experience, so also does the Conservative; and until public opinion is decidedly for progress the dead weight prevails. Not for a day did Bentham relax his strenuous exertions, but he changed his tactics; he turned from his mechanical workshop to the study of political dynamics, and he found what he wanted in the rising radicalism--'his principal occupation, in a word, was to provide political philosophy for radical reformers.'