level, in point of reputation, with the highest names in the republic of letters, has been less read and appreciated than any of his other writings.' In the same paragraph which contains the sentence just quoted, the characteristic which formed the peculiar value of James Mill's Analysis of the Phenomena of the Human Mind' is thus described :- In this work he evinced analytical powers rarely, if ever, surpassed; and which have placed him high in the list of those subtile inquirers who have attempted to resolve all the powers of the mind into a very small number of simple elements. Mr. Mill took up that analysis where Hartley had left it, and applied the same method to the more complex phenemona which the latter did not succeed in explaining.'

One of the most important results of James Mill's analysis was to show that belief, which Dugald Stewart and other writers say they can refer to nothing but instinct, is a case of the indissoluble association of ideas; that no instance can be adduced in which anything besides an indissoluble association of ideas can be shown in belief;' 'that in every instance of belief there is indissoluble association of the ideas.'1 Some remarkable examples are given in Mr. J. S. Mill's Logic' of the effect of inattention to or ignorance of the elementary laws of association in producing the illusion which measures the possibility of things in themselves by the human capacity of conceiving them. Dr. Whewell, speaking of the laws of chemical composition discovered by Dalton, says, 'How can we conceive combinations otherwise than as definite in kind and quantity?' and 'we cannot conceive a world in which this should not be the

1 Analysis, vol. i. pp. 281, 282,

case.' 1 The difficulty of conceiving such a world arose simply from the association produced in his own mind since the discovery of Dalton between the idea of combination and that of definite proportions. The case of the first law of motion is also instructive in a like manner. Dr. Whewell says: "Though the discovery of the first law of motion was made, historically speaking, by means of experiment, we have now attained a point of view in which we see that it might have been certainly known to be true, independently of experience.' On which Mr. J. S. Mill's makes these observations: Can there be a more striking exemplification than is here afforded of the effect of association? Philosophers, for generations, have the most extraordinary difficulty in putting certain ideas together; they at last succeed in doing so, and after a sufficient repetition of the process they first fancy a natural bond between the ideas, then experience a growing difficulty, which at last, by the continuation of the same progress, becomes an impossibility, of severing them from one another.' 2

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It would be difficult to overrate the importance of the service which James Mill did to philosophy by his analysis of the elementary laws of the association of ideas; for an ignorance of those laws has led to more false philosophy than probably anything else. An association between two ideas (an association which was merely the result of education, or early habits, or accident) was assumed to be conclusive proof that the association of those two ideas was a necessary and ultimate fact.

1 Mill's Logic, vol. i. pp. 322, 323, 1st edition; vol. i. pp. 273, 274, 7th edition.

2 J. S. Mill's Logic, vol. i. p. 322, 1st edition; vol. i. p. 273, 7th edition.

Whatever ideas certain philosophers could put together to their own satisfaction must, they affirmed, be the representatives of things that really existed. This assumption pervades the philosophy not only of Descartes, but of all the thinkers who received their impulse mainly from him; in particular, the two most remarkable among them, Leibnitz and Spinoza, from whom the modern German metaphysical philosophy is essentially an emanation.' Thus a boundless field was opened for the production of metaphysical entities. For the argument of Descartes, that the conception of any being proves the real existence of such a being, would prove the existence of centaurs, or indeed of anything, such as the wildest conceptions of Ariosto, or of the writers on knighterrantry who drove Don Quixote mad.

But the production of entities was only half of this process of bad or false metaphysics. The other half had relation to non-entities; under this form things which we cannot think of together cannot exist together, including that what we cannot think of as existing cannot exist at all; or, in other words, whatever is inconceivable must be false. There are many degrees of this error, which is most conspicuous in uneducated persons, like the English footman in Dr. Moore's 'Zeluco,' who objected to the French foot-guards being dressed in blue—a colour he pronounced only fit for the blue horse or the artillery;' or in fierce dogmatists of limited experience, like Johnson, who gave the lie direct to any man who told him of a water-spout or a meteoric stone. But philosophers of a very different kind from Boswell's 'sage' did not escape this mental

1 J. S. Mill's Logic, vol. ii. p. 356, 1st edition, London, 1843; vol. ii. p. 316, 7th edition, London, 1868.

snare. There are some circumstances connected with the history of this metaphysical error, which are calculated to place it in a strong light. The evil effects of bad metaphysics were strikingly displayed in the long war which the Cartesians waged against the theory of gravitation, on the ground that a thing cannot act where it is not;' an assumption which imposed even upon Newton himself, who, to meet the objection, imagined a subtle ether which filled up the space between the sun and the earth, and was the proximate cause of gravitation. And there is a passage in one of Newton's letters to Dr. Bentley, which, as Mr. J. S. Mill observes, 'should be hung up in the cabinet of every man of science who is ever tempted to pronounce a fact impossible because it appears to him inconceivable.' 'It is inconceivable,' said Newton, 'that inanimate brute matter should, without the mediation of something else, which is not material, operate upon and affect other matter without mutual contact. gravity should be innate, inherent, and essential to matter, so that one body may act on another at a distance through a vacuum, without the mediation of anything else, by and through which their action and force may be conveyed from one to another, is to me so great an absurdity, that I believe no man, who in philosophical matters has a competent faculty of thinking, can ever fall into it.'

That

Another great discovery of a philosopher of the same country and the same century as Newton also affords an instructive example of the difficulties with which truth has to contend. The greatest and most original discovery

1 J. S. Mill's Logic, ii. 359, 1st edition.

in physiology-that of the circulation of the blood-was so contrary to all the previous notions, in other words, to the association of ideas, of physicians, that the doctrine was not received by any physician who was more than forty years old, was violently opposed by some of the most distinguished, and Harvey's practice fell off considerably after the publication of his treatise On the Circulation of the Blood.' Harvey had anticipated such a result; and his words express his appreciation of the strength of 'inseparable association' as strongly as if he had used that expression instead of consuetudo.' 'Tantum,' he

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says, consuetudo, quasi altera natura, apud omnes valet.' Hume, as will be seen in the next essay, uses 'custom' in the same sense in which Harvey here uses consuetudo.' There is great significance in Harvey's expression, 'altera natura.' This altera natura' is the snare, the idol, the stumbling-block, of false philosophy. It may be mentioned, as an illustration of the philosophical sagacity of Harvey's mind, that the idea of the circulation of the blood was suggested to him by the consideration of the obvious use of the valves of the veins, which are so constructed as to impede the course of the blood from the heart through those vessels, while they permit it to pass through them to the heart.

Another important investigation in James Mill's 'Analysis' is the development of the pernicious consequences arising from the ambiguity of the Copula; first exposed by Hobbes in a passage quoted in the essay on Hobbes. James Mill has thus treated the subject:-'In all languages, the verb which denotes EXISTENCE1 has been em

1 The small capitals and italics in this extract are all copied from the original text.