The Online Library of Liberty

A project of Liberty Fund, Inc.

• Introduction
• Textual Introduction
• Preface to the Third Edition[*]
• Chapter I: Introductory Remarks
• Chapter II: The Relativity of Human Knowledge
• Chapter III: The Doctrine of the Relativity of Human Knowledge, As Held By Sir William Hamilton
• Chapter IV: In What Respect Sir William Hamilton Really Differs From the Philosophers of the Absolute
• Chapter V: What Is Rejected As Knowledge By Sir William Hamilton, Brought Back Under the Name of Belief
• Chapter VI: The Philosophy of the Conditioned
• Chapter VII: The Philosophy of the Conditioned, As Applied By Mr. Mansel to the Limits of Religious Thought
• Chapter VIII: Of Consciousness, As Understood By Sir William Hamilton
• Chapter IX: Of the Interpretation of Consciousness
• Chapter X: Sir William Hamilton’s View of the Different Theories Respecting the Belief In an External World
• Chapter XI: The Psychological Theory of the Belief In an External World
• Chapter XII: The Psychological Theory of the Belief In Matter, How Far Applicable to Mind
• Chapter XIII: The Psychological Theory of the Primary Qualities of Matter
• Chapter XIV: How Sir William Hamilton and Mr. Mansel Dispose of the Law of Inseparable Association
• Chapter XV: Sir William Hamilton’s Doctrine of Unconscious Mental Modifications
• Chapter XVI: Sir William Hamilton’s Theory of Causation
• Chapter XVII: The Doctrine of Concepts, Or General Notions
• Chapter XVIII: Of Judgment
• Chapter XIX: Of Reasoning
• Chapter XX: On Sir William Hamilton’s Conception of Logic As a Science. Is Logic the Science of the Laws, Or Forms, of Thought?
• Chapter XXI: The Fundamental Laws of Thought According to Sir William Hamilton
• Chapter XXII: Of Sir William Hamilton’s Supposed Improvements In Formal Logic
• Chapter XXIII: Of Some Minor Peculiarities of Doctrine In Sir William Hamilton’s View of Formal Logic
• Chapter XXIV: Of Some Natural Prejudices Countenanced By Sir William Hamilton, and Some Fallacies Which He Considers Insoluble
• Chapter XXV: Sir William Hamilton’s Theory of Pleasure and Pain
• Chapter XXVI: On the Freedom of the Will
• Chapter XXVII: Sir William Hamilton’s Opinions On the Study of Mathematics
• Chapter XXVIII: Concluding Remarks
• Appendices
• Appendix A: Manuscript Fragments
• Appendix B: Textual Emendations
• Appendix C: Corrected References
• Appendix D: Bibliographic Index of Persons and Works Cited In the Examination, With Variants and Notes

CHAPTER XX

On Sir William Hamilton’s Conception of Logic as a Science. Is Logic the Science of the Laws, or Forms, of Thought?

having discussed the nature of the three psychological processes which, together, constitute the operations of the Intellect, and having considered Sir W. Hamilton’s theory of each, we are in a condition to examine the general view which he takes of the Science or Art, whose purpose it is to direct our intellectual operations into their proper course, and to protect them against error.

Sir W. Hamilton defines Logic “the Science of the Laws of Thought as Thought.”^* He proceeds to justify each of the component parts of this definition. And first, is Logic a Science?

Archbishop Whately says that it is both a Science and an Art.^[*] He says this in an intelligible sense. He means that Logic both determines what is, and prescribes what should be. It investigates the nature of the process which takes place in Reasoning, and lays down rules to enable that process to be conducted as it ought. For this distinction, Sir W. Hamilton is very severe on Archbishop Whately. In the Archbishop’s sense of the words, he says, it never has been, and never could have been, disputed that Logic is both a Science and an Art. But

But if the difference between science and art is not the same as that between knowledge theoretical and practical, we are entitled to ask, what is it? If Archbishop Whately has placed the distinction where it is not, does his rather peremptory critic and censor tell us where it is? He declines the problem. “I am well aware that it would be no easy matter to give a general definition of science as contradistinguished from art, and of art as contradistinguished from science; but if the words themselves cannot validly be discriminated, it would be absurd to attempt to discriminate anything by them.”^[*] In the only other part of his Lectures where the distinction between Art and Science is touched on,^* he says that the “apparently vague and capricious manner in which the terms art and science are applied,” is not “the result of some accidental and forgotten usage,” but is founded on a “rational principle which we are able to trace.”^[†] But when the reader is expecting a statement of this rational principle, Sir W. Hamilton puts him off with a merely historical explanation. Without stating what the usage actually is, he derives it from a distinction drawn by Aristotle between “a habit productive,” and “a habit practical,” which he admits to be “not perhaps beyond the reach of criticism:” which he does not undertake to “vindicate,” and which he confesses to have been lost sight of by the moderns ever since they ceased to think “mechanical” arts “beneath their notice,”^[‡] all these being called arts without any reference to Aristotle’s supposed criterion.^† So that Sir W. Hamilton cannot claim even accordance with usage for the distinction which he seems, but does not distinctly profess, to patronize. Yet the principal fault he finds with Archbishop Whately’s distinction, is that it does not agree with usage. According to it, he says, “ethics, politics, religion, and all other practical sciences would be arts:”^* and he speaks of the “incongruity we feel in talking of the art of Ethics, the art of Religion, &c., though these are eminently practical sciences.”^†

Religion may ^abe here^a placed out of the question, for if there be incongruity with common feelings in calling Religion an art, there is quite as much in calling it a science, and especially a practical science, as if the theoretical doctrines of religion were no part of religion. If religion is either a science or an art, it must be both, and it is commonly understood to consist preeminently in things different from either, namely, a state of the feelings, and a disposition of the will. As for Ethics and Politics, the one and the other are, like Logic, both sciences and arts. Ethics, so far as it consists of the theory of the moral sentiments, and the investigation of those conditions of human well-being, disclosed by experience, which the practical part of Ethics has for its object to secure, is, in all senses of the word, a science. The rules or precepts of morals are an art. If there is any reluctance felt to speak of an art of morals, it is not because people prefer calling morals a science, but because most people are unwilling to look upon it as scientific at all, but prefer to regard it as a matter of instinct, ^bor of religious belief,^b or as depending solely on the state of the will and the affections. In the case of Politics there is not, even to the vulgarest apprehension, any incongruity in the use of the word art: on the contrary, “the art of government” is the vernacular expression, and “science of government” a sort of speculative refinement. Philosophic writers on politics have generally preferred to call their subject a science, in order to indicate that it is a fit subject for speculative thinkers, the word art being apt to suggest to modern ears (it did not to the ancients) something which is the proper business only of practitioners. In reality Politics includes both a science and an art. The Science of Politics treats of the laws of political phænomena; it is the science of human nature under social conditions. The Art of Politics consists (or would consist if it existed) of rules, founded on the science, for the right guidance and government of the affairs of society.

But, says Sir W. Hamilton, if the difference between Science and Art were merely that between affirmations and precepts, the distinction would be of no value, since it would “mark out no real difference between the various branches of knowledge, but only different points of view under which the same branch might be contemplated by us,—each being in different relations at once a science and an art.” Was it from Sir W. Hamilton we should have expected to hear that a distinction is of no value, because it does not mark a difference between two things, but a difference in the ^cpoints^c of view in which we may regard the same thing? How often has he told us, of many of the most important distinctions in philosophy, that they are precisely of this character! The remark, moreover, in the particular case, is so extremely superficial, that, coming from an author of whom it was by no means the habit to look only at the surface of things, it is one of the strongest of the many proofs which appear in his works, how little thought he had bestowed upon the sciences or arts, beyond his own speciality. The reason why systems of precepts require to be distinguished from systems of truths, is, that an entirely different classification is required for the purposes of theoretical knowledge, and for those of its practical application. Take the art of navigation, for example: where is the single science corresponding to this art, or which could with any propriety be included under the same name with it? Navigation is an art dependent on nearly the whole circle of the physical sciences: on astronomy, for the marks by which it determines the ship’s place on the ocean; on optics, for the construction and use of its instruments; on abstract mechanics, to understand and regulate the ship’s movements; on pneumatics, for the laws of winds; on hydrostatics, for the tides and currents, and the waves as influenced by ^dwinds^d ; on meteorology, for the weather; on electricity, for thunderstorms; on magnetism, for the use of the compass; on physical geography, and so on nearly to the end of the list. Not only has each one of all these sciences furnished its contingent towards the rules composing the one art of navigation, but many single rules could only have been framed by the union of considerations drawn from several different sciences. For the purposes of the art, the rules by themselves are sufficient, wherever it has been found practicable to make them sufficiently precise. But if the learner, not content with knowing and practising the rules, wishes to understand their reasons, and so possess science as well as art, he finds no one science corresponding in its object-matter with the art; he must extract from many sciences those truths of each which have been turned to practical account for the furtherance of navigation. All this is obvious to any one (not to say a person of Sir W. Hamilton’s sagacity), who has sufficiently reflected on the sciences and arts, to be aware of the relation between them. Archbishop Whately’s distinction, therefore, in no way merits the contemptuous treatment which it receives in the Lectures, and still more in the Discussions.^[*] It is eminently practical, it conforms to the natural and logical order of thought, and accords better with the ends and even with the custom of language, than any other mode in which Arts can be distinguished from Sciences. Sir W. Hamilton, though he condemns it, has not ventured to set up any competing distinction in its place, but (as we have seen) almost intimates that no satisfactory one can be found.

Next after the question whether Logic is a science, comes the consideration of its object-matter as a science, namely, “the Laws of Thought as Thought.”^[†] “The consideration of this head,” says our author, “divides itself into three questions—1. What is Thought? 2. What is Thought as Thought? 3. What are the Laws of Thought as Thought?”^* These three questions are successively discussed.

To the question, “What is Thought?” Sir W. Hamilton answers—It is not the direct perception of an object, nor its representation in memory or imagination, nor its mere suggestion by association, but is a product of intelligence. Intelligence acts only by comparison.

Further on, he again defines an act of thought as “the recognition of a thing as coming under a concept; in other words, the marking an object by an attribute or attributes previously known as common to sundry objects, and to which we have accordingly given a general name.”^* And subsequently, as “the comprehension of a thing under a general notion or attribute;”^† and again, “the cognition of any mental object by another in which it is considered as included; in other words, thought is the knowledge of things under conceptions.”^‡ And again, “Thought is the Knowledge of a thing through a concept or general notion, or of one notion through another.”^§

From these different expressions we may infer, that the author confines the name Thought to cases where there is a judgment; and, it would seem, a judgment affirming more than mere existence. We think an object, or make anything an object of thought, when we are able to predicate something of it; to affirm that it is something in particular; that it is a certain sort of thing; that it belongs to a class—has something which is (or may be) common to it with a number of other things; that it has, in short, a certain attribute, or attributes. This is intelligible, and unobjectionable: but our author’s technical expressions, instead of facilitating the understanding of it, tend, on the contrary, very much to confuse it. Like the transcendental metaphysicians generally, Sir W. Hamilton, when he attempts to state the nature of a mental phænomenon with peculiar precision, does it by a peculiarly unprecise employment of the common prepositions. What light is thrown upon the simple process of referring objects to a class, by calling it the recognition of one thing through, or in, or under, another? What distinct signification is conveyed by the phrases, “thinking a thing under a general notion,” “reducing it under a concept,” “knowing things under, or through, conceptions?” To find the meaning of the explanation we have to resort to the thing explained. The only passage in which the author speaks distinctly, is that in which he paraphrases these expressions by the following: “the marking an object by an attribute or attributes previously known as common to sundry objects, and to which we have accordingly given a general name.” To think of an object, then, is to mark it by an attribute or set of attributes, which has received a name, or (what is much more essential) which gives a name to the object. It gives to the object the concrete name, to which its own abstract name, if it has an abstract name, corresponds: but it is not indispensable that the attribute should have received a name, provided it gives one to the object possessing it. An animal is called a bull, in sign of its possessing certain attributes, but there does not exist an abstract word bullness. Having, then, in Sir W. Hamilton’s language, thought the object, by marking it with a name derived from an attribute, it is perhaps an allowable, though an obscure, expression, to say that we know the thing through the attribute, or through the notion of the attribute: but what is meant by saying that we know it, or think it under the attribute? We know it and think it, simply as possessing the attribute. The other phrase, while seeming to mean more, means less. Again, when we are asserted to “know one notion through another;” when, for example, we think, or judge, that men, meaning all men, are mortal; is this to know the notion Man through the notion Mortal? The knowledge we really have, is that the objects Men have the attribute mortality; in other words, that the outward facts by which we distinguish men, exist along with subjection to the outward fact, death. If there is a recommendation I would inculcate on every one who commences the study of metaphysics, it is, to be always sure what he means by his particles. A large portion of all that perplexes and confuses metaphysical thought, comes from a vague use of those small words.

After this definition of Thought, our author proceeds to explain what he means by Thought as Thought. He means, “that Logic is conversant with the form of thought, to the exclusion of the matter.”^* We have here arrived at one of the cardinal points in Sir W. Hamilton’s philosophy of Logic. However he may vary on other doctrines, to this he is constant, that the province of Logic is the form, not the matter, of thought. It is a pity that the only terms he can find to denote the distinction, are a pair of the obscurest and most confusing expressions in the whole range of metaphysics. Still more unfortunate ^eit is^e , that, thinking it necessary to employ such terms, he has never, in unambiguous language, explained their meaning. When Archbishop Whately, in somewhat similar phraseology, tells us that Logic has to do with the form of the reasoning process, but not with its matter, we know what he means.^[*] It is, that Logic is not concerned with the actual truth either of the conclusion or of the premises, but considers only whether the one follows from the other; whether the conclusion must be true if the premises are true. Sir W. Hamilton is not content to mean only this. He means much more; but if we wish to know what, the only information he here gives us is a quotation from a German philosopher, Esser.

Thus far Esser. The Form, therefore, of Thought, with which alone Logic is conversant, is not the object thought of, but “the kind and manner of thinking it.” It is not necessary to show that this explanation is insufficient. But to find any other, we must have recourse, not to Sir W. Hamilton, but to Mr. Mansel. One of the chapters of Mr. Mansel’s Prolegomena Logica is entitled “On the Matter and Form of Thought.” It commences as follows:

Let me here ask, had the block of marble no form at all when it came out of the quarry?

This is a fair account of the meaning of Matter and Form in the Kantian philosophy, and the philosophies which descend genealogically from the Kantian. But this meaning must always be taken with, and interpreted by, the characteristic doctrine of the Kantian metaphysics, that the mind does not perceive, but itself creates, all the most general attributes which, by a natural illusion, we ascribe to outward things; which attributes, consequently, are called, by that philosophy, Forms. Extension and Duration, for example, it calls forms of our sensitive faculty; Substance, Causality, Quantity, forms of our Understanding, which is our faculty of thought. These, however, are not what Sir W. Hamilton and Mr. Mansel^[*] mean, when they say that Logic is the science of the ^fforms^f of thought. They do not mean that it is the science of Substance, Causality, and Quantity. The truth is, that as soon as the word Form is stretched beyond its proper signification of bodily figure, it becomes entirely vague: every thinker uses it in a sense of his own. The only bond connecting its various meanings, is the negative one of opposition to Matter. Whenever anything is called Form, there is something which, relatively to it, is regarded as Matter: and whenever anything is called Matter, there is something capable of being superinduced upon it, which when superinduced will be styled its Form. How completely the notion of Form accompanies that of Matter as its relative opposite, we have an illustrious example in Aristotle, when he defines the Soul as the Form of the Body;^[*] so, at least, Sir W. Hamilton^g, very freely,^g translates ἐντελέχεια.^* It would be quite warranted by the practice of metaphysicians, to call any compound the form of its component elements; water, for instance, the form of hydrogen and oxygen. And since there is nothing that may not be regarded as matter relatively to something which can be constructed out of it, and which is form relatively to it, but matter relatively to some other thing, we have form within form, like a nest of boxes. Kant actually calls the conclusion of a syllogism the form of it, the premises being its matter: so that in every train of reasoning, the successive conclusions pass over one by one from Form to Matter.^[†] Without going this length, Sir W. Hamilton,^† after Krug, considers the propositions and terms as the matter of the syllogism, and the mode in which they are connected as its form. Yet propositions and terms (i.e. concepts) are classed by him as Forms of Thought. Thus it is impossible to draw any line between the Matter of Thought and its Form, or to convey any distinct conception of the province of a science by saying that it is conversant with the one and not with the other. We may, however, in a general way, understand Sir W. Hamilton to mean, that Logic is not concerned with the actual contents of our knowledge—with the particular objects, or truths, which we know—but only with our mode of knowing them: with what the mind does when it knows, or thinks, irrespectively of the particular things which it thinks about: with the theory of the act or fact of thinking, so far as that fact is the same in all our thought, or can be reduced to universal principles.

But the fact of thinking is a psychological phænomenon; and Logic is a different thing from Psychology. It is for the purpose of marking this difference that Sir W. Hamilton adds a third point to his definition of Logic, calling it the science not simply of Thought as Thought, but of the Laws of Thought as Thought. For Psychology also treats of thought, considered merely as thought; and professes to give an acount of Thought as a mental operation. In what, then, consists the difference between the two? I cannot venture to state it in any but our author’s own words.

If language has any meaning, this passage must be understood to say, that the “laws” or “forms” which are the province of Logic, are certain “phænomena” of thought, distinguished from its other phænomena by being necessarily present in it,—“such as cannot but appear,”—while the remaining phænomena “may or may not appear.” If this be meant, we are landed in a strange conclusion. There is a science, Psychology, which is the science of all mental phænomena, and among others, of the phænomena of Thought, and yet another science, Logic, is required to teach us its necessary phænomena. There is a portion of the properties of Thought which are expressly excluded from the science which treats of Thought, to be reserved as the matter of another science, and these are precisely its Necessary ^hqualities^h . Those which are merely contingent, “such as may or may not appear”—the properties which are not common to all thought, or do not belong to it at all times—these, it seems to be said, Psychology knows something about: but the Necessary properties, “such as cannot but appear”—the properties which all thoughts possess, which thought must possess, without the possession of which it would not be thought—these Psychology knows not of, and it is the office of a different science to investigate them. We may next expect to be told, that the science of dynamics knows nothing of the laws of motion, the composition of forces, the theory of continuous and accelerating force, the doctrines of Momentum and Vis Viva, &c.; it only knows of wind power and water power, steam power and animal power, and the accidents by flood and field which accompany them and disturb their operation.

This, however, supposes that our author means what he expressly says. It assumes that by the “Laws of Thought,” and the “Necessary Forms of Thought,” he means the modes in which, and the conditions subject to which, by the constitution of our nature, we cannot but think. But when we turn over a few pages, to the place where he is preparing to treat of those laws or necessary forms one by one, it appears that this is an entire mistake. Laws now no longer mean necessities of nature; they are laws in a totally different sense; they mean precepts: and the “necessary forms of thought” are not attributes which it must, but only which it ought to possess.

So that, after all, the real theory of Thought—the laws, in the scientific sense of the term, of Thought as Thought—do not belong to Logic, but to Psychology: and it is only the validity of thought which Logic takes cognisance of. It is not with Thought as Thought, but only as Valid thought, that Logic is concerned. There is nothing to prevent us from thinking contrary to the laws of Logic: only, if we do, we shall not think rightly, or well, or conformably to the ends of thinking, but falsely, or inconsistently, or confusedly. This doctrine is at complete variance with the saying of our author in his controversy with Whately, that Logic is, and never could have been doubted to be, in Whately’s sense of the terms, both a Science and an Art. For the present definition reduces it to the narrowest conception of an Art—that of a mere system of rules. It leaves Science to Psychology, and represents Logic as merely offering to thinkers a collection of precepts, which they are enjoined to observe, not in order that they may think, but that they may think correctly, or validly.

It appears to me, however, that our author, though inconsistent with himself, is much nearer the mark in this mode of regarding Logic than in the previous one. I conceive it to be true that Logic is not the theory of Thought as Thought, but of valid Thought; not of thinking, but of correct thinking. It is not a Science distinct from, and coordinate with, Psychology. So far as it is a science at all, it is a part, or branch, of Psychology; differing from it, on the one hand as a part differs from the whole, and on the other, as an Art differs from a Science. Its theoretic grounds are wholly borrowed from Psychology, and include as much of that science as is required to justify the rules of the art. Logic has no need to know more of the Science of Thinking, than the difference between good thinking and bad. A consequence of this is, that the Necessary Laws of Thought, those which our author in his first doctrine reserved especially to Logic, are precisely those with which Logic has least to do, and which belong the most exclusively to Psychology. What is common to all thought, whether good or bad, and inseparable from it, is irrelevant to Logic, unless by the light it may indirectly throw on something besides itself. The properties of Thought which concern Logic, are some of its contingent properties; those, namely, on the presence of which depends good thinking, as distinguished from bad.

I therefore accept our author’s second view of the province of Logic, which makes it a collection of precepts or rules for thinking, grounded on a scientific investigation of the requisites of valid thought. It is this doctrine which governs his treatment of the details of Logic, and it is by this that we must interpret the assertion that Logic has for its only subject the Form of Thought. By the Form of Thought we must understand Thinking itself; the whole work of the Intellect. The Matter of Thought is the sensations, perceptions, or other presentations (intuitions, as Mr. Mansel calls them),^[*] in which the intellect has no share; which are supplied to it, independently of any action of its own. What the mind adds to these, or puts into them, is Forms of Thought. Logic, therefore, is concerned only with Forms, since, being rules for thinking, it can have no authority but over that which depends on thought. Logic and Thinking are coextensive; it is the art of Thinking, of all Thinking, and of nothing but Thinking. And since every distinguishable variety of thinking act is called a Form of Thought, the Forms of Thought compose the whole province of Logic; though it would be hardly possible to invent a worse phrase for expressing so simple a fact.

But what are the Forms of Thought? Kant, as already observed, gives to that expression a very wide extent. He holds that every ⁱfundamentalⁱ attribute which we ascribe to external objects is a Form of Thought, being created, not simply discerned, by our thinking faculty.^[†] Neither Sir W. Hamilton nor Mr. Mansel goes this length; and at all events they do not consider the theory of the various attributes of bodies to be a part of Logic. It was incumbent on them, therefore, to state clearly what are the Forms of Thought with which Logic is concerned, and for which it supplies precepts. This question is never put, in an express form, by Sir W. Hamilton: but the answer which he rather leaves to be picked up than directly presents, may be gathered from his classification of our intellectual operations. These he reduces to three, Conception, Judgment, and Reasoning. He must have recognised, therefore, that number of general Forms of Thought. The Forms of Thought are Conception, Judgment, and Reasoning: Logic is the Science of the Laws (meaning the rules) of these three operations. If, however, we rigorously hold our author to this short list, we shall perpetually mistake his meaning: for (as already observed) the mode in which the word Form is used, allows of form within form to an unlimited extent. Every concept, judgment, or reasoning, after having received its form from the mind, may again be contemplated as the Matter of some further mental act; and the product of that further act (according to Kant),^[‡] or the relation of the product to the matter (according to Sir W. Hamilton and Mr. Mansel), is again a Form of Thought; as we find, to our confusion, when we proceed further, and the more profusely, the further we proceed. We have, first, however, to consider a proposition of Sir W. Hamilton, which qualifies his definition of the province of Logic. He says:

“Logic considers Thought, not as the operation of thinking, but as its product; it does not treat of Conception, Judgment, and Reasoning, but of Concepts, Judgments, and Reasonings.”^*

Let me begin by saying that I give my entire adhesion to this distinction, and propose to reform the definition of Logic accordingly. It does not, as we now see, relate to the Laws of Thought as Thought, but to those of the Products of Thought. Instead of the Laws of Conception, Judgment, and Reasoning, we must speak of the Laws of Concepts, Judgments, and Reasonings. This would be mere nonsense in the scientific sense of the word law: for a product, as such, can have no laws but those of the operation which produces it. But understanding by laws, as it seems we are intended to do, Precepts, Logic becomes the science of the precepts for the formation of concepts, judgments, and reasonings: or rather (a science of precepts being an improper expression) the science of the conditions on which right concepts, judgments, and reasonings depend. Thus, Logic is the Art of Thinking, which means of correct thinking, and the Science of the Conditions of correct thinking. This seems to me a sufficiently accurate definition of it. But, in attempting a deeper metaphysical analysis of the distinction he has just drawn, our author raises fresh difficulties. He says:

Just when the puzzled reader fancied that he had at last arrived at something clear, comes an explanation which throws all back into darkness. The learner who had been wandering in the mazes of “Thought as Thought,” laws which are not laws, and “Forms of Thought” in which Form stands for something which he never before heard of in connexion with that word, at last descried what seemed to be firm ground: he was told that Conception, Judgment, and Reasoning are acts of the mind, that Concepts, Judgments, and Reasonings are products of those acts, and that Psychology is conversant with the former and Logic with the latter. And now it turns out that the products are the acts. The two series of things are one and the same series. They are both of them only “Thought proper.” The product is another word for the act itself, considered in one of its aspects—“in reference to what thought is about.” It is curious that this should occur only a few pages after Whately has been rebuked for reducing a distinction to inutility, by making it coincide with a difference not between things, but between the aspects in which the same thing is regarded.

Sir W. Hamilton therefore is of opinion that the thinking act, though verbally, is not psychologically different from the thought itself. He does not hold, with Berkeley, that an Idea is a concrete object distinct from the mind, and contained in it, like furniture in a house; nor with Locke (if that was Locke’s opinion), that it is a modification of the mind, but a modification distinct from the mind’s act in cognising it; but with Brown, that a sensation is only myself feeling, and a thought only myself thinking. Concepts, Judgments, and Reasonings, are only acts of conceiving, judging, and reasoning; acts of thought, considered not in their relation to the thinking mind, but to their object, to “what thought is about.”^* But what is thought about? Not about Concepts, for all our thoughts are not about the thinking act. It must be about the objective presentation, the Anschauung, or Intuition, which the Concept represents, or from which it has been abstracted. According, therefore, to the doctrine here distinctly laid down by Sir W. Hamilton, there are but two things present in any of our intellectual operations; on one hand, the mind itself thinking (that is, conceiving, judging, or reasoning), and, on the other, a mental presentation or representation of the phænomenal Reality which it conceives, or concerning which it judges or reasons. I can understand that the thinking act, or in other words, the mind in a thinking state, may be contemplated in its relation to the Reality thought of, and may receive a name which connotes that Reality; but how does this entitle us to call it a product of thought? How can the act of thought, or the mind thinking, be looked upon, even hypothetically, as a product of thinking? How can Concepts, Judgments, and Reasonings be regarded as products of thought, ^jif^j they are the thought itself? Can they be both the act and something resulting from the act? Are they results and products of themselves?

I conceive that there is a way out of this difficulty; a sense in which the two assertions can be reconciled, though it has not been pointed out by Sir W. Hamilton, and is hardly compatible with some of his opinions. There is a difference between what can properly be called Acts of the mind, and the other mental phænomena which may be termed its passive States. And I know but one way of conceiving the distinction, in which it can possibly be upheld, namely, by considering as Acts only those mental phænomena which are results of Volition. Now, the first formation of a Concept, and generally (though not always) any fresh operation of judgment or reasoning, requires a mental effort, a concentration of consciousness upon certain definite objects, which concentration depends on the will, and is called Attention. When this takes place, the mind is properly said to be active. But after frequent repetition of this act of will, the associations to which it has given rise are sufficiently riveted to do their work spontaneously; the effort of attention, after becoming less and less, is finally null, and the operation, originally voluntary, becomes, in Hartley’s language, secondarily automatic.^[*] When this transition has been completed, what remains of the mental phænomenon has lost the character of an Act, and become numbered among passive States. It is now either a mere mental representation of an object, differing from those copied directly from sense, only in having certain of its parts artificially made intense and prominent; or it is a fasciculus of representations of imagination, held together by the tie of an association artificially produced. When the mental phænomenon has assumed this passive character, it comes to be termed a Concept, or, more familiarly and vaguely, an Idea, and to be felt as if it were, not the mind modified, but something in the mind: and in this ultimate phasis of its existence we may properly consider it, not as an act, but as the product of a previous act; since it now takes place without any conscious activity, and becomes a subject on which fresh activity may be exercised, by an act of voluntary attention concentrating consciousness on it, or on some particular part of it. This explanation, which I leave for the consideration of philosophers, would not have suited Sir W. Hamilton, since it would have required him to limit the extent which he habitually gave to the expression “mental act.”^k Every phænomenon of mind, down to the mere reception of a sensation, he regards as an act: therein differing from Kant, and annihilating the need and use of the word, the sole function of which is to distinguish what the mind originates, from what something else originates in the mind.

To return to the definition of Logic, as the science of the Forms of Thought, considered in relation, not to the thinking act itself, but, so far as they are distinguishable from it, to the products of thought. The products of thought are Concepts, Judgments, and Reasonings, and the Forms of Thought are Conception, Judgment, and Reasoning. Logic is the science of those Forms, so far as concerns the rules for the right formation of the products: or, as our author elsewhere phrases it, the science of the “formal conditions” of valid thinking.^[*] These modes of expression have a rare power of darkening the subject, but I am endeavouring to give them an intelligible interpretation, by means of that which they profess to explain. If, then, all thinking consists in adding, to given matter, a Form derived from the mind itself, what shall we say of the division, on which so much stress is laid, of Thinking itself into two kinds, Formal and Material Thinking, the first of which alone belongs to Logic, or at all events to pure Logic? Mr. Mansel has written a volume for the express purpose of showing that Logic is only concerned with Formal Thinking; and Sir W. Hamilton’s division of Logic into Pure and Modified, agrees with Mr. Mansel’s distinction.^[†] Yet, according to the definition we have just considered, all thinking whatever is Formal Thinking: since all thinking is either conceiving, judging, or reasoning, and these are the Forms of Thought. If Logic investigates the conditions requisite for the right formation of concepts, of judgments, and of reasonings, it investigates all the conditions of right thought, for there are no other kinds of thought than these; and if it does all this, what is left for the so-called Material Thinking which Logic is said not to be concerned with?

The answer to this question affords an additional specimen of the incurable confusion, in which the processes of thought are involved by the unhappy misapplication to them of the metaphorical word Form. Though Concepts, Judgments, and Reasonings, are said to be the forms of thought, and the only forms which thought takes, or rather gives; the metaphysicians who deal in Forms are in the habit of using phrases which signify that Concepts, Judgments, and Reasonings, though themselves Forms, have also, in themselves, a formal part and a material. Different concepts, judgments, and reasonings, have different matter, according to what it is that the conception, the judgment, or the reasoning, is about: and as whatever part of anything is not its Matter, is always styled its Form, whatever is common to all Concepts, or whatever belongs to them irrespectively of all differences in their matter, is said to be their Form; and so of Judgments and of Reasonings. Thus, the difference between an affirmative and a negative judgment is a difference of form, because a judgment may be either affirmative or negative whatever be the matter to which it relates. The difference between a categorical and an hypothetical syllogism is a difference of form, because it neither depends on, nor is it at all affected by, any differences in the matter. Logic, according to Mr. Mansel^[*] —pure Logic, according to Sir W. Hamilton—is conversant only with the Forms of Concepts, Judgments, and Reasonings, not with their Matter. Not only is it concerned exclusively with the Forms of thought, but exclusively with the Forms of those Forms. And here I fairly renounce any further attempt to deduce Sir W. Hamilton’s or Mr. Mansel’s ^lconception^l of Logic from their definitions of it. I collect it from the general evidence of their treatises, and I proceed to show why I consider it to be wrong.

Logic, Sir W. Hamilton has told us, lays down the laws or precepts indispensable to Valid Thought; the conditions to which thought is bound to conform, under the penalty of being invalid, ineffectual, not accomplishing its end. And what is, peculiarly and emphatically, the end of Thinking? Surely it is the attainment of Truth. Surely, if not the sole, at all events the first and most essential constituent of valid thought, is that its results should be true. Concepts, Judgments, and Reasonings, should agree with the reality of things, meaning by things the Phænomena or sensible presentations, to which those mental products have reference. A concept, to be rightly framed, must be a concept of something real, and must agree with the real fact which it endeavours to represent, that is, the collection of attributes composing the concept must really exist in the objects marked by the class-name, and in no others. A judgment, to be rightly framed, must be a true judgment, that is, the objects judged of must really possess the attributes predicated of them. A reasoning, to be rightly framed, must conduct to a true conclusion, since the only purpose of reasoning is to make known to us truths which we cannot learn by direct intuition. Even those who take the most limited view of Logic, allow that the conclusion must be true conditionally—provided that the premises are true. The most important, then, and at bottom the only important quality of a thought being its truth, the laws or precepts provided for the guidance of thought must surely have for their principal purpose that the products of thinking shall be true. Yet with this, according to Mr. Mansel, Logic has no concern;^[*] and Sir W. Hamilton reserves it for a sort of appendix to the science, under the title of Modified Logic. Questions of truth and falsity, according to both writers, regard only Material Thinking, while Formal Thinking is the province of Logic. The only precepts for thinking with which Logic concerns itself, are those which have some other purpose than the conformity of our thoughts to the fact. Yet every possible precept for thought, if it be an honest one, must have this for at least its ultimate object. What, then, is excluded from Logic, and what is left in it, by the doctrine that it is only concerned with Formal Thinking? What is excluded is the whole of the evidences of the validity of thought. What is included is part of the evidences of its invalidity.

In no case can thinking be valid unless the concepts, judgments, and conclusions resulting from it are conformable to fact. And in no case can we satisfy ourselves that they are so, by looking merely at the relations of one part of the train of thought to another. We must ascend to the original sources, the presentations of experience, and examine the train of thought in its relation to these. But we can sometimes discover, without ascending to the sources, that the process of thought is not valid; having been so conducted that it cannot possibly avail for obtaining concepts, judgments, or conclusions in accordance with fact. This, for example, is the case, if we have allowed ourselves to travel from premises to a conclusion through an ambiguous term. The process then gives no ground at all for believing the conclusion to be true: it is perhaps true, but we have no more reason to believe so than we had before. Or again, the concept, the judgment, or the reasoning may involve a contradiction, and so cannot possibly correspond to any real state of facts. It is with this part of the subject only, in the opinion of these philosophers, that Logic concerns itself. According to Mr. Mansel, Logic “accepts, as logically valid, all such concepts, judgments, and reasonings, as do not, directly or indirectly, imply contradictions; pronouncing them thus far to be legitimate as thoughts, that they do not in ultimate analysis destroy themselves . . . leaving to this or that branch of material science to determine how far the same products of thought are guaranteed by the testimony of this or that special experience.”^* Mr. Mansel has not here conceived his own view of the subject with his usual precision. He narrows the field of Logic more than he intends. That to which he confines the name of Logic, accepts as valid all concepts and judgments that do not imply contradictions, but by no means all reasonings. It rejects these not only when self-contradictory, but when simply inconclusive. It condemns a reasoning not only if it draws a conclusion inconsistent with the premises, but if it draws one which the premises do not warrant; not only if the conclusion must, but if it may, be false though the premises be true. For the notion of true and false will force its way even into Formal Logic, whatever pains Sir W. Hamilton and Mr. Mansel give themselves to make the notions of consistent and inconsistent, or of thinkable and unthinkable, do duty instead of it. The ideas of truth and falsity cannot be eliminated from reasoning. We may abstract from actual truth, but the validity of reasoning is always a question of conditional truth—whether one proposition must be true if others are true, or whether one proposition can be true if others are true. When Judgments or Reasonings are in question, “the conditions of the thinkable” are simply the conditions of the believable.

What Mr. Mansel and Sir W. Hamilton really mean, is to segregate from the remainder of the theory of the investigation of truth, as much of it as does not require any reference to the original sufficiency of the groundwork of facts, or the correctness of their interpretation, and call this exclusively Logic, or Pure Logic. They assume that concepts have been formed and judgments made somehow; and if there is nothing within the four corners of the concept or the judgment which proves it absurd, that is, no self-contradiction, they do not question it further. Whether it is grounded on fact or on mere supposition, and if on fact, whether the fact is represented correctly, they do not ask; but think only of the conditions necessary for preventing errors from getting into the process of thought, which were not in the notions or the premises from whence it started. The theory of these conditions (of which the doctrine of the Syllogism is the principal part) Mr. Mansel calls Logic, and Sir W. Hamilton Pure Logic. The expression “Formal Logic,” which is sometimes applied to it, is perhaps as distinctive and as little misleading as any other, and is that which, for want of a better, I am content to use. That this part of Logic should be distinguished and named, and made an object of consideration separately from the rest, is perfectly natural. What I protest against, is the doctrine of Sir W. Hamilton, Mr. Mansel, and many other thinkers, that this part is the whole; that there is no other Logic, or Pure Logic, at all; that whatever is more than this, belongs not to a general science and art of Thinking, but (in the words of Mr. Mansel) to this or that material science.^[*]

This doctrine assumes, that with the exception of the rules of Formal, that is, of Syllogistic Logic, no other rules can be framed which are applicable to thought generally, abstractedly from particular matter: That a general theory is possible respecting the relations which the parts of a process of thought should bear to one another, but not respecting the proper relations of all thought to its matter: That the problem which Bacon set before himself, and led the way towards resolving, is an impossible one: That there is not, and cannot be, any general Theory of Evidence: That when we have taken care that our notions and propositions concerning Things shall be consistent with themselves and with one another, and have drawn no inferences from them but such the falsity of which would be inconsistent with assertions already made, we have done all that a philosophy of Thought can do—and the agreement and disagreement of our beliefs with the laws of the thing itself, is in each case a special question, belonging to the science of that thing in particular: That the study of nature, the search for objective truth, does not admit of any rules, nor its attainment, of any general test. For if there are such rules, if there is such a test, and the consideration of it does not belong to Logic, to what science or study does it belong? There is no other science, which, irrespectively of particular matter, professes to direct the intellect in the application of its powers to any matter on which knowledge is possible. These philosophers must therefore think that there can be no such rules, or that if there are, they can only be of the vaguest possible description. Sir W. Hamilton says as much.

It is very true that all Sir W. Hamilton can tell us of it is soon told. Nothing can be more meagre, trite, and indefinite than the little which he finds to say respecting what he calls Modified Logic. And no wonder, when we consider the following extraordinary deliverance, which I quote from the conclusion of his Thirtieth Lecture on Logic. Speaking of Physical Science generally, Sir W. Hamilton thus expresses himself:

Sir W. Hamilton had good reason for confining his own logical speculations to a minor and subordinate department of the Science and Art of Thinking, when he was so destitute as this passage proves, of the preliminary knowledge required for making any proficiency in the other and higher branch. Every one who has obtained any knowledge of the physical sciences from really scientific study, knows that the questions of evidence presented, and the powers of abstraction required, in the speculations on which their greater generalizations depend, are such as to task the very highest capacities of the human intellect: and a thinker, however able, who is too little acquainted with the processes actually followed in the investigation of objective truth, to be aware of this fact, is entitled to no authority when he denies the possibility of a Philosophy of Evidence and of the Investigation of Nature; inasmuch as his own ^macquirements^m do not furnish him with the means of judging whether it is possible or not.^*

If any general theory of the sufficiency of Evidence and the legitimacy of Generalization be possible, this must be Logic κατ’ ἐξοχήν, and anything else called by the name can only be ancillary to it. For the Logic called Formal only aims at removing one of the obstacles to the attainment of truth, by preventing such mistakes as render our thoughts inconsistent with themselves or with one another: and it is of no importance whether we think consistently or not, if we think wrongly. It is only as a means to material truth, that the formal, or to speak more clearly, the conditional, validity of an operation of thought is of any value; and even that value is only negative: we have not made the smallest positive advance towards right thinking, by merely keeping ourselves consistent in what is, perhaps, systematic error. This by no means implies that Formal Logic, even in its narrowest sense, is not of very great, though purely negative, value. On the contrary, I subscribe heartily to all that is said of its importance by Sir W. Hamilton and Mr. Mansel. It is good to have our path clearly marked out, and a parapet put up at all the dangerous points, whether the path leads us to the place we desire to reach, or to another place altogether. But to call this alone Logic, or this alone Pure Logic, as if all the rest of the Philosophy of Thought and Evidence were merely an adaptation of this to something else, is to ignore the end to which all rules laid down for our thinking operations are meant to be subservient. The purpose of them all, is to enable us to decide whether anything, and what, is proved true. Formal Logic conduces indirectly to this end, by enabling us to perceive, either that the process which has been performed is one which could not possibly prove anything, or that it is one which will prove something to be true, unless the premises happen to be false. This indirect aid is of the greatest importance; but it is important because the end, the ascertainment of truth, is important; and it is important only as complementary to a still more fundamental part of the operation, in which Formal Logic affords no help.

I do not deny the scientific convenience of considering this limited portion of Logic apart from the rest—the doctrine of the Syllogism, for instance, apart from the theory of Induction; and of teaching it in an earlier stage of intellectual education. It can be taught earlier, since it does not, like the inductive logic, presuppose a practical acquaintance with the processes of scientific investigation; and the greatest service to be derived from it, that of keeping the mind clear, can be best rendered before a habit of confused thinking has been acquired. Not only, however, is it indispensable that the larger Logic, which embraces all the general conditions of the ascertainment of truth, should be studied in addition to the smaller Logic, which only concerns itself with the conditions of consistency; but the smaller Logic ought to be, at least finally, studied as part of the greater—as a portion of the means to the same end; and its relation to the other parts—to the other means—should be distinctly displayed. If thought be anything more than a sportive exercise of the mind, its purpose is to enable us to know what can be known respecting the facts of the universe: its judgments and conclusions express, or are intended to express, some of those facts: and the connexion which Formal Logic, by its analysis of the reasoning process, points out between one proposition and another, exists only because there is a connexion between one objective truth and another, which makes it possible for us to know objective truths which have never been observed, in virtue of others which have. This possibility is an eternal mystery and stumbling-block to Formal Logic. The bare idea that any new truth can be brought out of a Concept—that analysis can ever find in it anything which synthesis has not first put in—is absurd on the face of it: yet this is all the explanation that Formal Logic, as viewed by Sir W. Hamilton, is able to give of the phænomenon; and Mr. Mansel expressly limits the province of Logic to analytic judgments—to such as are merely identical. But what the Logic of mere consistency cannot do, the Logic of the ascertainment of truth, the Philosophy of Evidence in its larger acceptation, can. It can explain the function of the Ratiocinative process as an instrument of the human intellect in the discovery of truth, and can place it in its true correlation with the other instruments. It is therefore alone competent to furnish a philosophical theory of Reasoning. Such partial account as can be given of the process by looking at it solely by itself, however useful and even necessary to accurate thought, does not dispense with, but points out in a more emphatic manner the need of, the more comprehensive Logic of which it should form a part, and which alone can give a meaning or a reason of existence to the Logic styled Formal, or to the reasoning process itself.

[* ]Lectures, Vol. III, p. 4.

[[*] ]Elements of Logic, p. 1.

[† ]Lectures, Vol. III, p. 11; see also Discussions, pp. 133-4.

[[*] ]Lectures, Vol. III, pp. 11-12.

[* ]Ibid., Vol. I, pp. 115-19.

[[†] ]Ibid., p. 116.

[[‡] ]Ibid., pp. 118-19.

[† ]I give the Aristotelian distinction in Sir W. Hamilton’s words. “In the Aristotelic philosophy the terms πρᾶξις and πρακτικός, that is, practice and practical,—were employed both in a generic or looser, and in a special or stricter signification. In its generic meaning, πρᾶξις, practice, was opposed to theory or speculation, and it comprehended under it, practice in its special meaning, and another co-ordinate term to which practice, in this its stricter signification, was opposed. This term was ποίησις, which we may inadequately translate by production. The distinction of πρακτικός and ποιητικός consisted in this: the former denoted that action which terminated in action,—the latter, that action which resulted in some permanent product. For example, dancing and music are practical, as leaving no work after their performance: whereas painting and statuary are productive, as leaving some product over and above their energy. Now Aristotle, in formally defining art, defines it as a habit productive, and not as a habit practical, ἕξις ποιητικὴ μετὰ λογου [see Nichomachean Ethics, pp. 334-5 (VI, iv, 1140a21-2)]; and though he has not always himself adhered strictly to this limitation, his definition was adopted by his followers, and the term in its application to the practical sciences (the term practical being here used in its genuine meaning), came to be exclusively confined to those whose end did not result in mere action or energy. Accordingly as Ethics, Politics, &c., proposed happiness as their end, and as happiness was an energy, or at least the concomitant of energy, these sciences terminated in action, and were consequently practical, not productive. On the other hand, Logic, Rhetoric, &c., did not terminate in a mere—an evanescent action, but in a permanent—an enduring product. For the end of Logic was the production of a reasoning, the end of Rhetoric the production of an oration, and so forth.” (Lectures, Vol. I, pp. 117-18.) The English language expresses the same distinction by the two verbs, to do and to make.

[* ]Discussions, p. 134.

[† ]Lectures, Vol. I, p. 116.

[a-a]651 here be

[b-b]+67, 72

[c-c]651 point

[d-d]651 wind

[[*] ]See Lectures, Vol. III, pp. 11-12; Discussions, pp. 130-4.

[[†] ]See Lectures, Vol. III, p. 4.

[* ]Ibid., p. 12.

[† ]Ibid., pp. 13-14.

[* ]Ibid., p. 15.

[† ]Ibid., p. 21.

[‡ ]Ibid., p. 40.

[§ ]Ibid., p. 43.

[* ]Ibid., p. 15.

[e-e]651, 652 is it

[[*] ]See, e.g., Elements of Logic, pp. 13-14.

[[†] ]Lectures, Vol. III, p. 15; cf. Esser, Logik, p. 4.

[* ]Prolegomena Logica, pp. 226-7. [The words in square brackets are Mill’s.]

[[*] ]Ibid., p. 233.

[f-f]651 form [printer’s error?]

[[*] ]See Aristotle, On the Soul, pp. 66-70 (II, i, 412a-b).

[g-g]+67, 72

[* ]See Reid, [Inquiry,] p. 202, and Sir W. Hamilton’s foot-note [pp. 202n-3n]. A still odder example is given by Reid in his Essays on the Active Powers. “In the scholastic ages, an action good in itself was said to be materially good, and an action done with a right intention was called formally good. This last way of expressing the distinction is still familiar among theologians.” (Works, [ed. Hamilton,] pp. 649-50.)

[[†] ]See Kant, Logik, in Prolegomena zu einer jeden Künftigen Metaphysik, die als Wissenschaft wird Auftreten Können und Logik, in Werke, Vol. III, p. 306.

[† ]Lectures, Vol. III, pp. 287-8. [See Krug, Logik, §85.] So also Mr. Mansel, Prolegomena Logica, p. 235.

[* ]Lectures, Vol. III, p. 24.

[h-h]651, 652, 67 properties

[* ]Lectures, Vol. III, pp. 78-9. It might have been supposed that the double meaning of the word law, though in the last century it could blind even a Montesquieu, had been sufficiently written about since that time, to be understood by minds of far less calibre than Sir W. Hamilton’s: yet in this passage he does not recognise it, but seems rather to think that the difference between a law in the scientific, and a law in the legislative or ethical sense, does not turn on an ambiguity of the word, but on the difference between “the world of mind” and “the world of matter:” a “free intelligence” knowing only precepts, which it has power to disobey, and not being ruled, like the physical world, by laws from which it cannot escape. Yet Sir W. Hamilton is the same philosopher who is for ever telling us of necessities of thought which are absolutely irresistible to us—from which we can by no mental effort emancipate ourselves; and upon this alleged fact the larger half of his philosophy is grounded. When we find all this forgotten, we almost fancy that we have opened a volume of some other writer by mistake. Treating of the same question in another place, our author remembers his own philosophy much better. In the Lecture in which he divides mental science into the “Phænomenology of Mind” and its “Nomology,” the former a classification and analysis of our mental faculties, the latter an investigation of their “laws,” the word Laws always stands for “necessary and universal facts,” “the Laws by which our faculties are governed,” not precepts by which they ought to be governed: and of these necessary and universal facts it is expressly said that the Laws of Thought, with which Logic is concerned, are a part. They are classed with “the Laws of Memory,” “the Laws of Association,” “the laws which govern our capacities of enjoyment,” all of which are correctly described as necessary facts, and not as precepts. (Ibid., Vol. I, pp. 121ff.) The whole of this is thrown to the winds when the time comes for taking up Logic as a separate science.

[[*] ]See Prolegomena Logica, pp. 9-10.

[i-i]+72

[[†] ]Kritik der Reinen Vernunft, pp. 745-7.

[[‡] ]Ibid.

[* ]Lectures, Vol. III, p. 73.

[† ]Ibid., pp. 73-4.

[* ]Sir W. Hamilton holds a corresponding theory in regard to the identity of an imagination with the imagining act. “A representation considered as an object is logically, not really, different from a representation considered as an act. Here object and act are merely the same indivisible mode of mind viewed in two different relations. Considered by reference to a mediate object represented, it is a representative object: considered by reference to the mind representing and contemplating the representation, it is a representative act. A representative object being viewed as posterior in the order of nature, but not of time, to the representative act, is viewed as a product; and the representative act being viewed as prior in the order of nature, though not of time, to the representative object, is viewed as a producing process.” (“Dissertations on Reid,” [Note B,] p. 809.) Sir W. Hamilton has not explained how, in the order of nature, or in any other order, a thing can be prior, or posterior, or prior and posterior, to itself.

[j-j]651, 652 when

[[*] ]See Observations on Man, Vol. I, p. 104.

[k]651, 652, 67 It has been said, not without reason, of Condillac and others, that their psychological explanations treat our mental nature as entirely passive, ignoring its active side. The contrary error may with equal reason be imputed to Sir W. Hamilton, that of ignoring the passive side.

[[*] ]See, e.g., Lectures, Vol. III, pp. 64, 79.

[[†] ]See Prolegomena Logica, pp. 227-9, 237-40.

[[*] ]See, e.g., ibid., pp. 240-5.

[l-l]651, 652 conceptions

[[*] ]See ibid., pp. 237-40, 265-8.

[* ]Ibid., p. 265.

[[*] ]Ibid.

[* ]Lectures, Vol. IV, App. i, p. 232.

[† ]Ibid., p. 138. [See Bacon, Novum Organum, in Works, Vol. I, pp. 189 and 205 (Bk. I, Aphs. 82 and 105). Cf. De Augmentis Scientiarum, in ibid., p. 620 (Bk. V, Chap. ii).]

[m-m]651 requirements [printer’s error?]

[* ]Accordingly all that Sir W. Hamilton has to say concerning the requisites of a legitimate Induction, is that there must be no instances to the contrary, and that the number of observed instances must be “competent.” (Lectures, Vol. IV, pp. 168-9.) If this were all that “a Material or Objective Logic” could “tell us,” Sir W. Hamilton’s treatment of it would be quite justified. The point of view of a complete Induction, namely one in which the nature of the instances is such, that no other result than the one arrived at is consistent with the universal Law of Causation, had never risen above Sir W. Hamilton’s horizon. The same low reach of thought, not for want of power, but of the necessary knowledge, shows itself in every part of the little he says concerning the investigation of Nature. For example, he implicitly follows the mistake of Kant in affirming an intrinsic difference between the inferences of Induction and those of Analogy. [Cf. Kant, Logik, in Werke, Vol. III, pp. 320-1.] Induction, he says, infers that “if a number of objects of the same class possess in common a certain attribute, . . . this attribute is possessed by all the objects of that class;” while Analogy infers that “if . . . two or more things agree in several internal and essential characters . . . they agree, likewise, in all other essential characters, that is, they are constituents of the same class.” (Lectures, Vol. IV, pp. 165-6.) A little more familiarity with the subject would have shown him that the two kinds of argument are homogeneous, and differ only in degree of evidence. The type of them both is, the inference that things which agree with one another in certain respects, agree in certain other respects. Any argument from knownpoints of agreement to unknown, is an inference of analogy: and induction is no more. Induction concludes that if a number of As have the attribute B, all things which agree with them in being As agree with them also in having the attribute B. The only peculiarity of Induction, as compared with other cases of analogy, is, that the known points of agreement from which further agreement is inferred, have been summed up in a single word and made the foundation of a class. For further explanations, see my System of Logic, Bk. III, Chap. xx. [In Collected Works, Vol. VII, pp. 554ff.]