them stand sometimes for one thing and sometimes for another; the wilful doing whereof, can be imputed to great folly, or greater dishonesty."1 Again -"Knowledge and reasoning require precise determinate ideas. The multiplication and obstinacy of disputes, which have so laid waste the intellectual world, is owing to nothing more than to this ill use of words. For though it is generally believed that there is great diversity of opinions, in the volumes and variety of controversies the world is distracted with, yet the most I can find that the contending learned men of different parties do, in their arguings one with another, is, that they speak different languages." Locke then says that by proper attention being paid to language, Moral Science may be reduced to demonstration."Upon this ground it is, that I am bold to think that Morality is capable of demonstration, as well as mathematics; since the precise real essence of the things moral words stand for may be perfectly known. . . . And, therefore, the negligence and perverseness of mankind cannot be excused, if their discourses in morality be not much more clear than those in Natural Philosophy. . . . Yet this, the least that can be expected, that in all discourses, wherein one man pretends to instruct or convince another, he should use the same word constantly in the same sense; if this were done, which nobody can refuse without great disingenuity, many of the books extant might be spared: many of the controversies in dispute would be at an end, several of these great volumes, swollen with ambiguous words now used in one sense, and by and bye in another, would shrink into a very narrow compass.' "13 How true all this is of Economics, any one who has read the subject can tell! So also Mill perfectly acknowledges in a general way the importance of true conceptions. "How to define a name may not only be an inquiry of considerable difficulty and intricacy, but may involve considerations going deep into the nature of the things which are denoted by the name." 4 Again "Few people have reflected how great a knowledge of things is required to enable a man to affirm that any given argument turns wholly upon words. There is, perhaps, not one of the leading terms of philosophy which is not used in almost innumerable shades of meaning, to express ideas more or less widely different from one another. Between two of these ideas a sagacious and penetrating mind will discern, as it were intuitively, an unobvious link of connection, upon which, though perhaps unable to give a logical account of it, he will found a 1 Essay, bk. iii. c. 10, § 5. 3 Essay, bk. iii. c. 2, § 16, 17, 26. Essay, bk. iii. c. 10, § 22. 4 Logic, bk. i. c. 8, § 7. perfectly valid argument, which his critic, not having so keen an insight into the things, will mistake for a fallacy turning on the double meaning of a term. And the greater the genius of him who safely leaps over the chasm, the greater will probably be the crowing and vain glory of the mere logician who, hobbling after him, evinces his own superior wisdom by pausing on its brink, and giving up as desperate his proper business of bridging it over."1 And concluding the chapter, he says—“And since upon the result of this inquiry respecting the causes of the properties of a class of things, there incidentally depends the question what shall be the meaning of a word, some of the most profound and most valuable investigations which philosophy presents to us have been introduced by, and have offered themselves under the guise of inquiries into the definition of a name." 2 After so distinctly recognizing the importance of true definitions, it might naturally be expected that Mill should bestow extraordinary care on the ascertainment and settlement of the Fundamental Concepts of Economics, the obscurity and confusion of which, every one knows, have given rise to the greater part of the controversies in the subject. But just as in the former case, where Mill, after having amply acknowledged that Moral Science is to be cultivated in the spirit and method of Physical Science, when he comes to Economics in particular, turns his back upon himself, and maintains that it is an à priori science; so here, after amply acknowledging the importance of true Philosophical Concepts, when he comes to Economics he says "It is no part of the design of this treatise to aim at metaphysical nicety of definition, where the ideas suggested by a term are already as determinate as practical purposes require."3 But what definition in Economics is as determinate as practical purposes require? Not a single one! And in a subsequent chapter we shall see how contradictory are many of Mill's definitions. On the Formation of General Axioms. 18. Having obtained General Concepts or Definitions of Quantities treated about, our next purpose is to discover the General Law which governs their relations to each other, and in searching for this, we must observe that, there can be but ONE General Theory at the basis of all phenomena. In particular classes of cases, there may undoubtedly be other circumstances which may aggravate, neutralize, or overpower, and seemingly reverse the Logic, bk. i. c. 8, § 7. Logic, bk. i. c. 8, § 7. 3 Pol. Econ. p. 2. 2 General Theory; but for all that, it is there, and acts universally. In several different sciences no doubt different General Theories have prevailed, such as in Astronomy, Optics, Heat, Electricity, &c. ; but no Physical Philosopher ever dreamt of explaining every different class of phenomena by a distinct theory. No one ever thought of writing a book on Astronomy, in which one chapter was written on the Ptolemaic Theory, another chapter on the Copernican Theory, and another chapter on Tycho Brahe's Theory. No one ever thought of writing a book on Optics, one part of which was based upon the Emission Theory, and another on the Wave Theory of Light, and so on of the other sciences. It has always been clearly understood that there could be but ONE General Theory which governed all phenomena, though liable to be modified by disturbing causes in particular cases. And the business of the Physical Philosopher has always been to discover which is the true General Theory; and the grand business of the Baconian, or Inductive, Logic, has been to discover and lay down the principles which are to decide which is the true Theory. In politics, no doubt, we require the spirit of compromise, and many contradictions are tolerated for the sake of general peace. But in science, toleration and compromise are impossible. It is always a mortal combat between rival theories. All but one must perish; and it is the business of Inductive Logic to pronounce the doom of Life or Death. Now without even yet determining what Economics is, we may lay this down, that if it be a Physical Science, as is so often asserted, there can be but ONE General Theory of the relations between Economic Quantities. To break up Economic phenomena into distinct classes of cases, and to maintain that there is a distinct fundamental Theory, or Axiom, or Law, governing each class of cases, would be utterly abhorrent to the fundamental principles of Natural Philosophy. Bacon gives abundant precepts for the determination of the truth of rival theories, and he enforces the necessity of carefully devised experiments (and in the Moral Sciences possible feigned cases), and the attention necessary to contrive a variety of them, and to extend the inquiry generally. "For no one successfully investigates the nature of a thing in the thing itself." And he advises us to imitate the Divine Wisdom, which in the first day created light only. So we must endeavour to gather from all sorts of experience, and to discover true causes and general principles, and to devise "experimenta lucifera" for this purpose, or instances contrived with the express view of testing general principles before we go to practice. For he says that all true knowledge consists in knowing true causes, and that which in Theory is the cause, in Practice is the rule. "For though we are chiefly in pursuit of the practical and active part of science, we must wait for the time of the harvest, and not reap the moss or the green corn. For we well know that general principles, once rightly discovered, will carry whole troops of works with them, and will produce effects not in single instances, but in multitudes."1 Some writers of eminence, indeed, seem to think that Bacon has neglected too much, or even omitted, the deductive part of science, or the explanation of phenomena by general principles. But we cannot agree to this. He has clearly and repeatedly asserted that his Philosophy consists, first, of the eliciting general conceptions and general axioms from particular cases-the Inductive part-the ascending to abstract principles from concrete cases; and, secondly, the descending part, or the application of general principles, so obtained by Induction, to the explanation of phenomena. "Axioms duly and orderly formed from particulars, easily discover the way to new particulars, and thus render sciences active." 2 "The true method of experience, on the contrary, first lights the candle, and then by means of the candle, shews the way; commencing as it does with experience duly ordered and digested, not bungling or erratic, and from it educing Axioms, and from established Axioms again new experiments." 3" From the new light of Axioms, which, having been educed from these particulars by a certain method and rule, shall in their turn point out the way again to new particulars, greater things may be looked for. For our road does not lie on a level, but ascends and descends; first ascending to Axioms, then descending to works."4" And the truth is that the knowledge of simple natures well examined and defined is light; it gives entrance to all the secrets of nature's workshop, and virtually includes and draws after it whole bands and troops of works, and opens to us the source of the noblest axioms." 5 It clearly appears, therefore, that Deduction was not only an essential part of the Baconian Philosophy, but its very aim and object, because it was the practical part of it. The very aim of Bacon was, by discovering true science or the knowledge of causes, to be able to govern the world of reality, or effects. To say, therefore, that Bacon omitted the Deductive part is manifestly as great an error as that of J. B. Say, who declared that Bacon was quite 1 Distributio Operis. Nov. Org. bk. i. aph. 24. 4 Nov. Org. bk. i. aph. 103. ignorant that the method of his Philosophy was applicable to anything but Physical Science. Mill is, therefore, also in error when he says that a revolution in science is peaceably taking place, and that we are reverting from the Inductive to the Deductive method. Even if it were true, it is not a revolt from, but the express fulfilment of, the Baconian Philosophy. And we think the example Mill has selected peculiarly unfortunate, because the practical triumphs of the astronomer are entirely due to the Theoretical, or Inductive, discovery of the fundamental Laws of Mechanics. Astronomy is nothing whatever but a practical example of the general laws of Mechanics, and is the most sublime proof of the truth of the Baconian Philosophy. 12. One of the great fundamental Laws of Inductive Logic pervading every part of the Novum Organum, and expressing its very spirit, is called the Law of Continuity, and is thus described by Whewell, Nov. Org. Renov. p. 221 : "A quantity cannot pass from one amount to another by any change of conditions, without passing through all the intermediate magnitudes, according to the intermediate conditions." "This Law may often be employed to correct inaccurate deductions, and to reject distinctions which have no real foundation in nature. For example: The Aristotelians made a distinction between motion according to nature (as that of a body falling vertically downwards) and motion contrary to nature (as that of a body moving along a horizontal plane); the former they held became naturally quicker and quicker, the latter naturally slower and slower. But to this it might be replied that a horizontal line may pass by gradual motion through various inclined positions to a vertical position, and thus the retarded motion may pass into the accelerated; and hence there must be some inclined plane on which motion is naturally uniform, which is false, and therefore the distinction of such kinds of motion is unfounded." That is to say, there is no point whatever at which one kind of motion passes into another. Again :-"The evidence of the Late of Continuity resides in the universality of those Ideas, which enter into our apprehension of Laws of Nature. When of two quantities one depends upon the other, the Law of Continuity necessarily governs the dependence. Every philosopher has the power of applying this Law, in proportion as he has the faculty of apprehending the Ideas which he employs in his Induction, with the same clearness and steadiness which belong to the fundamental Ideas of Quantity, Space, and Number. To those who possess this faculty, the Law is a rule of very wide and decisive application. Its |