that can be relied on. But Mill thinks that the variety of experience that supports it in this case, its constant verification by new experience and the probability that, had there been any exception to it, that exception would have come to light, justify our confidence in it as the ground of all the laws of nature. He does not recognise that these grounds for belief-whatever their value may be—all assume the postulate of uniformity which he is endeavouring to justify.

ous.

A later and more comprehensive discussion of his philosophical views, especially in a psychological regard, is given in his Examination of Sir William Hamilton's Philosophy and of the principal philosophical questions discussed in his writings. This work was published in 1865; and, as his habit was, the author amplified it greatly in subsequent editions by replies to his critics. In this case the criticisms were exceptionally numerThe book focused the whole controversial energy of the period belonging to the two opposed schools, the intuitional and the empirical; and, in spite of its controversial character, it became the leading text-book of that psychological philosophy which had been adumbrated by Hume. It is a work which shows Mill's powers at their most mature stage. He criticises with severity the theory which he sets out to examine; but he is alive to the awkward places in his own position. Among the numerous doctrines on which he left the impress of his workmanship, none excited more attention at the time of the book's publication, or are of greater permanent importance, than his doctrines of the external world and of the self. There is nothing fundamentally original about his views on these topics; but his discussion of both illustrates his ability to see further into the facts than his predecessors, and his candour in recording what he sees, along, however, with a certain disinclination to pursue an enquiry which might land him definitely on the other side of the traditional lines. Mill's doctrine is essentially Humean, though, as regards the external world, he prefers to call it Berkeleyan; and here he is the inventor of a phrase: matter is "permanent possibility of sensation." The phrase is striking and useful; but a possibility of sensation is not sensation, and the permanence which he attributes to the possibility of sensation implies an objective order: so that the reduction of matter to sensation is

implicitly relinquished when it appears to be affirmed in words. Mind, in somewhat similar fashion, is reduced to a succession of feelings or states of consciousness. But the fact of memory proves a stumbling-block in his way; he cannot explain how a succession of feelings should be conscious of itself as a succession; and he implicitly admits the need of a principle of unity. Thus, he almost relinquishes his own theory and only avoids doing so explicitly by falling back on the assertion that here we are in presence of the final inexplicability in which ultimate questions always merge.

In spite of the prominence of the ethical interest in his mind and in spite, also, of numerous ethical discussions in his other writings, Mill's sole contribution to the fundamental problem of ethical theory was his small volume Utilitarianism, which first appeared in Fraser's Magazine in 1861 and was reprinted in book-form in 1863. Perhaps, he regarded the fundamental positions of Benthamism as too secure to need much elaboration. What he offers is a finely conceived and finely written defence of utilitarian ethics, into which his own modifications of Bentham's doctrine of life are worked. He holds that the sanctions of this doctrine are not weaker than those of any other doctrine, and that, in its own nature, it is neither a selfish nor a sensual theory. It is not selfish, because it regards the pleasures of all men as of equal moment; it is not sensual, because it recognises the superior value of intellectual, artistic and social pleasures as compared with those of the senses. But Mill fails in trying to establish a logical connection between the universal reference of the ethical doctrine and the egoistic analysis of individual action to which his psychology committed him. And he is so determined to emphasise the superiority of the pleasures commonly called "higher," that he maintains that, merely as pleasures, they are superior in kind to the pleasures of the senses, irrespective of any excess of the latter in respect of quantity. In so doing he strikes at the root of hedonism, for he makes the ultimate criterion of value reside not in pleasure itself but in that characteristic-whatever it may turn out to be-which makes one kind of pleasure superior to another.

Mill's social and political writings, in addition to occasional articles, consist of the short treatise Considerations on Repre

sentative Government (1860), Thoughts on Parliamentary Reform (1859), the essays On Liberty (1859) and On the Subjection of Women (1869), Essays on some Unsettled Questions of Political Economy (1831, 1844) and Principles of Political Economy (1848). The method appropriate to these topics had been already discussed in the chapters on "the Logic of the Moral Sciences" included in his Logic. He sought a via media between the purely empirical method and the deductive method. The latter, as employed by his father, was modelled on the reasonings of geometry, which is not a science of causation. The method of politics, if it is to be deductive, must belong to a different type, and will (he holds) be the same as that used in mathematical physics. Dynamics is a deductive science because the law of the composition of forces holds; similarly, politics is a deductive science because the causes with which it deals follow this law: the effects of these causes, when conjoined, are the same as the sum of the effects which the same causes produce when acting separately. Like his predecessors, Mill postulated certain forces as determining human conduct: especially, selfinterest and mental association. From their working he deduced political and social consequences. He did not diverge from the principles agreed upon by those with whom he was associated. Perhaps, he did not add very much to them. But he saw their limitations more clearly than others did: the hypothetical nature of economic theory, and the danger that democratic government might prove antagonistic to the causes of individual freedom and of the common welfare. To guard against these dangers he proposed certain modifications of the representative system. But his contemporaries, and even his successors of the same way of thinking in general, for long looked upon the dangers as imaginary, and his proposals for their removal were ignored. The essay On Liberty-the most popular of all his works-is an eloquent defence of the thesis "that the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection," but, as an argument, it meets everywhere with the difficulty of determining the precise point at which the distinction between self-regarding and social (even directly social) activity is to be drawn. Sir James Fitzjames Stephen, accepting Mill's utilitarian criterion, raked his

positions with a fire of brilliant and incisive, if unsympathetic, criticism in Liberty, Equality, Fraternity (1873).

Mill's Political Economy has been variously regarded as an improved Adam Smith and as a popularised Ricardo. Perhaps the latter description is nearer the mark. Its essential doctrines differ little, if at all, from those of Ricardo; the theory of the "wages fund," for example, is formulated quite in the spirit of Ricardo, though this theory was afterwards relinquished or modified by Mill in consequence of the criticisms of William Thomas Thornton. But the work has a breadth of treatment which sometimes reminds one of Adam Smith: the hypothetical nature of economic theory was not overlooked, and the "applications to social philosophy" were kept in view. In spite of his adherence to the maxim of laissez faire, Mill recognised the possibility of modifying the system of distribution, and, with regard to that system, he displayed a leaning to the socialist ideal, which grew stronger as his life advanced. His methodical and thorough treatment of economics made his work a text-book for more than a generation, and largely determined the scope of most of the treatises of his own and the succeeding period, even of those written by independent thinkers.

Mill died at Avignon in 1873. After his death, were published his Autobiography (1873) and Three Essays on Religion: Nature, The Utility of Religion and Theism (1874). These essays were written between 1850 and 1870 and include the author's latest thoughts on ultimate questions. He had been educated in the belief that speculation on ultimate questions is futile; in his works he had always maintained the attitude afterwards called agnosticism, for which he was willing to adopt Comte's term positivism; he accepted, also, in general, Comte's doctrine on this point, though always dissociating himself from the latter's political and social theories. But, even while, in his book Auguste Comte and Positivism (1865), accepting the view that the essential nature and ultimate causes of things are inscrutable, he holds that this "positive mode of thought is not necessarily a denial of the supernatural," but only throws it back beyond the limits of science. His posthumous essays show a further development. In that on nature (the earliest of the series), he dwells upon the imperfections of the

cosmic order as showing that it cannot have been the creation of a being of infinite goodness and power; in the last essay of the volume, he approaches a tentative and limited form of theism— the doctrine of a finite God.

For more than a generation Mill's influence was dominant in all departments of philosophical and political thought; he had the initiative, and set the problems for his opponents as well as for his adherents; and his works became university text-books. This holds of politics, economics, ethics, psychology and logic. A striking reaction against his influence is shown in the work of William Stanley Jevons, professor at Manchester and afterwards in London, whose economic and logical writings are distinguished by important original ideas. In his Theory of Political Economy (1871), he introduced the conception of final (or marginal) utility, which, subsequently, has been greatly developed in the analytic and mathematical treatment of the subject. In logic, also, he laid the foundations for a mathematical treatment in his Pure Logic (1864) and Substitution of Similars (1869); and, in his Principles of Science (1874), he fully elaborated his theory of scientific inference, a theory which diverged widely from the theory of induction expounded by Mill. As time went on, Jevons became more and more critical of the foundations of Mill's empirical philosophy, which he attacked unsparingly in discussions contributed to Mind.

George Grote, the historian of Greece, an older contemporary and early associate of Mill, deserves mention here not only for his works on the philosophies of Plato and Aristotle, but, also, for some independent contributions to ethics, published together under the title Fragments on Ethical Subjects (1876). He had little sympathy with Mill's approximations to types of thought opposed to the traditional utilitarianism. In this respect he agreed with Alexander Bain, professor at Aberdeen, a writer of far greater importance in a philosophical regard. Bain was younger than Mill and long outlived him; he assisted him in some of his works, especially the Logic; he wrote numerous works himself; but his pre-eminence was in psychology, to which his chief contributions were two elaborate books, The Senses and the Intellect (1855) and The Emotions and the Will (1859). The psychology of James Mill and of J. S. Mill was,