the other, Reason, would be interpreted as covering Induction and Deduction. Sir W. Hamilton includes the whole under one head, variously named by him, the Elaborative or Discursive Faculty, Comparison, the Faculty of Relations, and also Thought, in a certain narrow sense, as when Logic is defined the science of the laws of Thought.' In the detailed exposition, he divides the operations of the Faculty into two parts, corresponding to the division into Abstraction and Reason. (Lectures on Metaphysics, II, 277.) This seems the best view to take of the scientific faculty. As regards the mental forces concerned-the chief of these being Similarity-there is no essential difference between Abstraction on the one hand, and Induction, or Deduction, on the other; although the subjects and products are so far different, that it is convenient to illustrate them separately.

In remarking above that Similarity does not explain the whole of the scientific faculty, I mean that Abstraction, Induction, and Deduction, frequently involve something besides the bringing together of resembling particulars or facts; what that something is, will be seen in the chapter on the Constructive operations of the Intellect.

BUSINESS AND PRACTICE.

39. In Business or Industry, in the power of intelligence applied to the affairs of life, in Practical Genius, we find exemplified the discovery of deep identities amid superficial differences. In the inventions of practical art, no less than in the discoveries of science, the identifying faculty is called into play.

The labours of Watt, in the steam engine, might with great propriety be farther cited, to correspond with the greatest strokes of scientific identification. Perhaps his 'governor balls' is the most illustrative example for our present purpose. Here he had to devise a method of opening and closing a valve, in connexion with the diminution or increase of the speed of a very rapid wheel movement; and no device in the range of existing machinery

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would answer this object. He had, therefore, to venture out into the region of mechanical possibility, to seek among mechanical laws in general, or among very remote natural phenomena, for a parallel situation; and he found the only case that has yet been hit upon, namely, the action of a centrifugal force, where two revolving bodies part, or come together, according as the rate of revolution is accelerated or retarded. I am not aware of any stroke of remote identification in the history of mechanical invention, surpassing this in intellectual reach; if such a power of bringing together the like out of the unlike were of usual occurrence, the progress of discovery would be incalculably more rapid. Another instance of Watt's power of identifying a practical situation with some other case where the requisite construction is given, was the suggestion of a lobster-jointed pipe, for conveying water across the bottom of the river Clyde. The inventive genius is ever ready with a suggestion derived from some already existing device, disguised from the sight of other men, either in the arrangements of nature or in the constructions of art. Identifying power, although not expressing everything that constitutes an inventor, will be found a prominent feature in the character. As in the other departments, so here also, the identifying faculty must operate in a suitable region of previous acquisitions and experience.

In the able administration of private business and public affairs, we shall often be able to detect the same force at work, although not always designated invention or genius. Either in meeting new cases, or in bringing superior methods to bear upon old, there is a march of mind, an advance over routine, which marks the able administrator; and here too the link of power consists in a more than ordinary force of identification. When a present emergency is exactly like a previous one, it recalls that one without difficulty, and is treated as that was treated; when it corresponds exactly to no one before, a subtler mind is wanted; some parallel must be sought for, away from the routine of cases. Into

quite remote regions of affairs, the man of penetration is carried, and finds something in point where perhaps no parallel was ever drawn before. The application of the Syllogism to Law pleadings was a great legal improvement, which has persisted while scholastic forms have gone generally into decay. No routine lawyer was capable of such an innovation. If for illustration's sake we suppose it to have been the work of one person, it implies a mind that came to the study of law previously prepared with the scholastic training, and detecting in the pleadings before the courts a real identity in form with the discussions of the schools, although hitherto conducted with no such method or precision. The transference of the syllogism to the legal reasonings would be the consequence of this feeling of identity; and hence would arise that capital requirement of making parties plead separately to the law, and to the facts of the case, instead of huddling up both in one argument as is usually done in the controversies of every-day life.*

It is usual for practical devices to be first employed in obvious cases, and thence transferred to other cases of a like nature, but of more complexity. Thus, in the great institution of the Division of Labour now so widely ramified over all departments of industry, there could be traced a progressive application; we should find it commencing in manual industry, and in the separation of the primitive classes of agriculturist, artisan, trader, soldier, and priest; and thence, in later times especially, extended into the warehouse and the manufactory, into public business, and into scientific research. In every new step, there would arise, in the mind of some one person or other, a feeling of similarity between the exigencies of a work in hand and the cases where the

The system of separating the law and the facts, in legal pleadings, did not arise as I suppose in the text, and as might have been the origin, from an application of the scholastic logic, but from our Saxon institution of trial by jury, where the facts were decided on by the jurors, and the law declared by the judge. Nevertheless, the illustration answers our purpose, even in its hypothetical character.

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method of divided labour was already in operation; and this identification would suggest the further extension of the practice. I do not at present speak of the faculty required for overcoming the difficulties of detail in all new applications of old machinery (although here too it would be found, that a fertile power of recalling identities in diversity would be the principal instrument of success, in so far as the intellect was concerned), but confine myself to the suggestion of a device taken from some parallel case.

In the progress of free governments, there has been gradually diffused, from the lower to the higher and more difficult posts, the principle of responsibility as a check upon the abuse of power. This practice grew up by a process of extension, until, in the constitutional governments of Great Britain and the United States, it came to include every executive officer in all departments of state. The experience of the practice, with the more humble functionaries, suggested its application to the exactly parallel case of superior officers, and after much struggle, not of an intellectual kind, it got to be introduced into modern free communities, as it had been. in the constitution of ancient Athens.

The principle of not interfering with individual tastes and sentiments, except in so far as these affect the legitimate happiness of others, is recognized in certain cases, and has had a tendency to expand itself by assimilation into cases encumbered with obstructive circumstances. Hence has sprung up what amount of toleration in belief and in conduct we now possess; although the difficulty in proceeding far with this extension, shows how effectually the love of domination and of uniformity may stifle the assimilating action of the intellect.

In the suggestions of a practical mind, the identification should always turn upon the relevant circumstances, and overcome other attractions of sameness on irrelevant points. To attain to this characteristic is the end of a practical education, which makes the person familiar with the aspects that serve the ends contemplated. Thus, a lawyer in recover

ing, from his past experience, the precedents and analogies suitable to a case in hand, is impelled by the force of similarity working in his mind; but, of the many peculiarities of the case, he excludes the assimilating action of all except the one that would govern its decision before a judge. His education must serve him in making this discrimination; and if (as may happen) he is by natural temperament keenly alive to this one feature constituting legal relevancy, and indifferent to all other points of interest in the case, he is a born lawyer, just as Newton, with his natural avidity for mathematical relations and indifference to sensuous and poetic effects, was a born natural philosopher; or Milton, by the opposite character, was a born poet. That nature should chance to turn out a legal mind is not singular or surprising, for it is only a variety of the scientific or logical intellect, using verbal forms as the instrument, and implying an obtuseness to all the more popular and interesting features of human life. To secure a rigorous uniformity in dealing with disputes, scientific definitions must be made, and equally applied to the most diversified cases.

40. The last form of practical ability that I shall here advert to is persuasion. This implies that some course of conduct shall be so described, or expressed, as to coincide, or be identified, with the active impulses of the individuals addressed, and thereby command their adoption of it by the force of their own natural dispositions. A leader of banditti has to deal with a class of persons whose ruling impulse is plunder; and it becomes his business to show them that any scheme proposed by him will lead to this end. A people with an intense overpowering patriotism, as the old Romans, can be acted on by proving that the interests of country are at stake. The fertile oratorical mind is one that can identify a case in hand with a great number of the strongest beliefs of an audience; and more especially with those that seem, at first sight, to have no connexion with the point to be carried. The discovery of identity in diversity is never more called for, than in the attempts to move men to adopt some un