It was the practical aspect of the science that chiefly interested Mill in economics. It was this still more, if possible, that inspired him in his more specifically political works, the treatises on _Liberty_, on the _Subjection of Women_, and on _Representative Government_. In his schemes of reform Mill was, in his own time, considered extreme; he would now be thought moderate. The caution of his speculation is nowhere more clearly marked than in his _Liberty_. It pleads certainly for more power to the state than the Manchester School would have granted; but it does so only in order to preserve the real freedom of the individual. In the _Subjection of Women_ Mill was a pioneer on a road which has been well trodden since; and, for good or ill, there has been steady progress towards the triumph of his ideas. In _Representative Government_ he shows a faith, probably excessive, in political machinery; but, whether it can do all Mill supposed or not, such machinery is necessary, and his labour tended to make it better. [Sidenote: William Whewell (1794-1866).] Over against Mill, with some points of resemblance, but more of difference, may be set William Whewell, who, in 1841, became Master of Trinity College, Cambridge, and who acquired an immense reputation both for encyclopædic knowledge and for brilliant wit. On the human side he was certainly more attractive than Mill. Like the latter, he was fascinated by the great performances and the boundless promise of science; and he is one of those whose task it has been to formulate a philosophy of science. To this task he devoted himself more exclusively than Mill, and he brought to it a greater knowledge of scientific processes and discoveries. Moreover, his point of view was different. Mill was a pure empiricist. Whewell held that empiricism alone could not explain even itself; and he therefore taught that there was necessary truth as well as empirical truth. This was at once the starting point of his controversy with Mill and the ground-work of his writings, the _History of the Inductive Sciences_ (1837) and the _Philosophy of the Inductive Sciences_ (1840). He is best known by his _Novum Organum Renovatum_, which was originally a portion of the second work. Whewell's strong point is his great knowledge of the history of science. His inductive theory is somewhat loose. It amounts to no more than a succession of tests of hypotheses; and of these tests the most stringent, prediction and consilience of inductions, are open to the fatal objection that they are not and cannot be applied to all inductions. Mill's inductive methods also are more stringent in appearance than they prove to be in reality; but they at least point to an ideal towards which it is always possible to strive. [Sidenote: Sir William Hamilton (1788-1856).]