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faculty, not the only function of the soul. There are then certain portions of our The soul has passions, pleasures, and pains; knowledge which have been accumulated it affects the body, and is affected through within historical times; the faculties by the bodily organs in ways to which the term which they have been gained are faculties knowledge is not applicable; it determines not possessed to anything like their full exaction in its individual capacity; collectively, tent by the savage or the uncultivated permany souls being cognisant of each other's son. Of this class are the physical sciexistence through the senses, and being ences; and accordingly in the case of the urged by desire, form those combinations physical sciences we can distinguish very which we term political or social. From accurately between their logic and their histhe consideration of the soul in these its tory, between the reasons which compel us different capacities arise many sciences, to believe in them and the actual record of ethics, æsthetics, politics, social science, their growth. We can observe the processphysiological psychology, etc.--all of which es of thought, induction and deduction, that sciences together may be called the psycho- secure to us this knowledge: we vitally logical sciences. Now the science which accept these processes, not merely as printreats of knowledge—its growth, its laws, ciples that have obtained during the past, its development—is one of these sciences; but as principles that must guide us for the for to know is one of the functions of the future – in a much more stringent and soul—as some think, the supreme function, thorough sense than that in which the prinand that without which any consideration ciples which underlie any material science of the rest is futile (the opinion, as is to be may be said to guide our action. By far supposed, of Schelling and Hegel)—but at the larger portion, however, of our knowany rate, one of the functions.
ledge, is acquired so very shortly after our But now, selecting out of the whole num- birth, that we lose all recollection of the ber of the psychological sciences this sci- process by which it was gained. The faculence, which treats of the development of ties of sight, hearing, taste, smell, touch; knowledge, the question arises, Is this sci- the knowledge of ourselves, our emotions, ence throughout its whole scope to be desig- and feelings; these we are said to possess nated by the title of logic? It is not; and naturally. But it cannot be doubted by yet it may be entirely surveyed from the any one who reflects on the subject, that logical point of view. But there is also though we, through some mysterious pro'another point of view from which we may cess of inheritance, come into possession of look on it. It is clear that we may treat these kinds of knowledge easily and quickof the development of our knowledge to ly, they were not gained easily or quickly some extent in a simply historical fashion. by those who first possessed them. Thought We may say, Thus and thus were different and effort must have been necessary for branches of knowledge successively added their acquisition ; and in that thought and on to our previous stock, without dwelling effort must have been at work universal on the truth and reality of the knowledge principles similar to those which gain and thus added, on its conformity with the es
secure to us the knowledge which we are sential laws of all knowledge. If, on the now for the first time gathering together. other hand, we wish to treat of knowledge And the very difficult science which treats from the logical point of view, the history of this knowledge, which we possess so seof the development of knowledge sinks into curely as to call it elementary and primary, minor importance, and is only used to illus- is entitled Metaphysics; and here it is imtrate the essential laws of knowledge. That possible to distinguish between the logic this distinction is possible to a certain ex- and the historical growth of our knowledge
. tent is plain from the different character of Why I believe that this chair, this table, such a book as Dr. Whewell's History of this house, stands before me, and, Howl the Inductive Sciences from any professedly came to this belief, are no doubt two differlogical treatise, such as that of Mr. Mill. ent questions; but to treat them separately In Dr. Whewell, the principles illustrate is very hard indeed. In general, the Gerthe history; in Mr. Mill
, the history illus- man metaphysicians have treated of the fortrates the principles. But how far is this mer, the logical, question; the English psy. distinction, between the science which treats chologists of the latter, the historical, to of the logical justification of our knowledge the solution of which they have invoked the and the science which treats of its historical aid of physiology. But, in point of fact, it development, capable of being carried out? is very difficult to treat of either question This is a question that must be entered satisfactorily, apart from the other
. And upon more fully, if we wish to know the hence, though logic can in part be studied exact relation of logic to metaphysics. quite without reference to metaphysics, yet
there is a part of logic which is closely en- ever, to hear what previous writers have twined with metaphysics, and at present in- said as to the difference between these two separable from it."
sciences. If we could enter into the mind of an in- Mr. Mill is hardly clear enough on the fant, and see it, with a swiftness of thought subject. “Of the science," he says, "which unparalleled in later life, gather together its expounds the operations of the human unknowledge of the material world, of colours, derstanding in the pursuit of truth, one essounds, smells, tastes, feelings, and the con- sential part is the inquiry, What are the nections of these, it is not to be doubted but facts which are the objects of intuition or that the fundamental principles which gov- consciousness, and what are those which we ern the development of knowledge must be merely infer? But this inquiry has never rigorously adhered to; the infant must be been considered a portion of logic. Its a perfect, though unconscious, logician. place is in another and a perfectly distinct What, however, is more particularly to be department of science, to which the name noticed is this : it is not quite certain that metaphysics more particularly belongs these primary processes of the mind are that portion of mental philosophy which exactly of that nature which can be called attempts to determine what part of the induction and deduction, the only logical furniture of the mind belongs to it origiprocesses that we can be said fully to un- nally, and what part is constructed out of derstand. Even in our present mathemati- materials furnished to it from without. To cal processes, it is difficult to characterize this science appertain the great and much the method of our knowledge by these debated questions of the existence of matterms; we feel, though we cannot describe, ter; the existence of spirit, and of a distinca difference. It cannot be thought impossi- tion between it and matter; the reality of ble that a further analysis of our logical time and space, as things without the mind, processes, such as that which Hegel at- and distinguishable from the objects which tempted, may be necessary when we come are said to exist in them. ... To the same to consider the processes of our elementary science belong the inquiries into the nature knowledge. But into the Hegelian logic it of Conception, Perception, Memory, and is impossible to enter here; though it is Belief; all of which are operations of the necessary to point out the relation which it understanding in the pursuit of truth, but bears to the ordinary logic. Such a logic, with which, as phenomena of the mind, or if correctly carried out--and I express no with the possibility which may or may not opinion whether Hegel carried it out cor- exist of analysing any of them into simpler rectly or not-must be more penetrating phenomena, the logician as such has no conthan ordinary logic. It may appear to con
To this nce must also be referred tradict ordinary logic; just as to superficial the following, and all analogous questions : minds the Copernican system appears to To what extent our intellectual faculties and contradict the Ptolemaic system. It requires our emotions are innate—to what extent the a scientific mind to discern that, in a much result of association: whether God and duty more important sense, the Copernican sys- are realities, the existence of which is manitem is the development of the Ptolemaic fest to us à priori by the constitution of our system. Just so, while the possibility of rational faculty; or whether our ideas of this deeper logic must be vindicated, and them are acquired notions, the origin of the inquiry into it urged, it is certain that which we are able to trace and explain, and it cannot really be other than the develop- the reality of the objects themselves a quesment, through an acuter analysis, of our tion not of consciousness or intuition, but ordinary logic.
of evidence and reasoning. The province I have endeavoured to present above a of logic must be restricted to that portion correct view of the difference, and at the of our knowledge which consists of infersame time the relation, between logic and ences from truths previously known, whether metaphysics. Logic is the science which those antecedent data be general proposielucidates the fundamental principles that tions, or particular observations and perrun through the whole of our knowledge. ceptions. Logic is not the science of BeMetaphysics is the investigation, at once lief, but the science of Proof or Evidence” logical and historical, into a certain portion (vol. i. pp. 7, 8). It may be noticed, by of our knowledge, namely, the elementary the way, that the proposition that the portion. Thus logic and metaphysics are province of logic must be restricted to that intersecting sciences, though this often es- portion of our knowledge which consists of capes notice, from the fact that the portion inferences,” is not quite consistent with the where both intersect is the most abstruse observation which Mr. Mill makes on the portion of either. It will be proper, how- I succeeding page, that “the field of logic is
co-extensive with the field of knowledge." is time to consider the science in itself, its And the fact is that, though Mr. Mill has a present condition, and its prospects. highly positive and precise idea of what he . The most fundamental axiom of logic redoes intend to write about (which is indeed lates to the sharp separation between truth the first necessity in an author), his concep- and falsehood. A judgment, an opinion, a tion of the subjects outside his scope-of proposition, must be true or not true. what he styles “metaphysics ”—is some- This, it may be thought, is sufficiently obwhat vague. His metaphysical questions vious; but something remains to be said are a very miscellaneous set. None of of it. The axiom assumes of course that them are meaningless; but the meaning of the judgment or proposition has a clear many of them is extremely indeterminate; meaning; that it is a hard solid fact knockthey are mere tentative expressions, and ing at the doors of the mind and challeng. can by no means be said to sketch the out- ing entrance; that it is not idle words or line of a science. And if it be asked, Do fluctuating thought. Indeed, the very terms we not really know some things by intui- judgment and proposition do, perhaps, imtion, others by inference ? and if so, must ply this; an unmeaning judgment, an unnot these separate kinds of knowledge be meaning proposition, is no real judgment, the subjects of different sciences ? it must no real proposition. It should, however, be be replied, that the division thus stated, noticed that, though in logic the distinction whether theoretically possible or not, is between true and false is the most thoroughpractically impossible. No fact, no truth, going possible, it is one which a prudent comes before us, of which it can be said, mind will be rather shy of urging sharply This is known to us at once and purely, on all occasions. The sifting of thought without any mental process whatever lead- necessary before a clear judgment or propoing up to it. We must take knowledge as sition can be arrived at is in most cases a we find it, as conglomerate. In short, great deal more than half the battle in the metaphysics, as the science which treats of discovery of truth. Nevertheless, if truth our elementary knowledge, is intelligible; is ever to be attained, we must in all cases while if defined as the science of our intui- come at last to a final decision :-Is this tive knowledge, it challenges questions that alleged truth true or not true? And there are not easily answered.
fore the distinction between truth and falseMuch better is the account given by Kant hood is the fundamental distinction of logic. and his followers of the difference between What I have tried to put forward in loose logic and metaphysics. According to them, explanatory fashion in the above paragraph, logic deals with the form, i. e., the univer- is technically expressed by logicians in the sal principles, of thought : metaphysics, laws, as they are called, of identity, contrawith the matter of thought, the actual ob- diction, and excluded middle. The law of jects that we know. The definition of logic identity says, A thing is what it is. The is indeed unexceptionable: that of meta- law of contradiction says, A thing is not physics is more vague; it leaves it still what it is not. The law of excluded middoubtful what kind of inquiry into the mat- dle says, What you think, is either true or ter of thought it is which metaphysics pro- not true. These three laws are rightly conposes.
If it were answered that meta- sidered the primary laws of logic. physics proposes a historical inquiry into But, how are we to discern truth from the development of our knowledge, this ac- falsehood, to separate corn from chaff
, to count of the matter would not very essen- educe a cosmos out of the chaos of sensatially differ from that which has been ad- tion and opinion, to raise an enduring fabric vanced in the above pages. It would differ of knowledge ? Logicians have from the from it in two ways only: first, in the total first endeavoured to generalize the means exclusion of logic from the sphere of meta- by which this is done, and with growing physics, whereas, according to the account success; though it would be idle to deny here given, they are in certain parts inex- that obscurity yet rests on many parts of tricably entwined ; and secondly, in ex- the subject. Aristotle, the founder of the tending metaphysics beyond the region of science, laid down the syllogism as the uniour elementary knowledge. But Kant's versal model after which all reasoning proconception of metaphysics was clearly not ceeds, and by which alone certain truth can that of a historical science. The meta- be attained.' What the syllogism is, and physics of Hamilton had more of a histori- what are the different forms of it, is much cal character; but the question is one that
too well known for it to be necessary to cannot be pursued further in this place. enter into a detailed description here. The Here must terminate the investigation into general type of it is as follows: What is the external relations of logical science; it true of a class, is true of everything con
tained in the class; or, to use Kant's phrase- did not admit of being reduced to rule and
—“ rules"--were ultimate pieces of know- and be unnoticed, though a full view of the
like result in either case. To this general | former occasion, will have a tendency to be process of argumentation Mr. Jevons has excited in the consciousness of the infant, given the appropriate name of “the substi- and may perhaps actually be so excited. tution of similars."
The infant will observe A, and remember It would be superfluous to dwell at length B. So far we have only an example of on the explanation of the theory; but it memory. But it is a law of human nature should be noticed that a logician who was that we should look forward to the future, more of a mental analyst than Mr. Mill and endeavour to anticipate it. Suppose would lay a stress which Mr. Mill has not then the infant's mind to be at this moment laid on the invariable presence, even in an in a state of expectancy—of looking forargument from particulars to particulars, of ward for something actually to happen a general element-of an element capable within the sphere of his cognisance,-what of being referred to any case. For, even if will he expect? He cannot expect A, bethe reasoner himself does not so refer it, or cause he is observing A, and what is meant erect the grounds of his conclusion into a by his expecting is, what does he think will general proposition, we, if we analysed his happen when I has disappeared ? Now, thoughts, must so refer it for him. And next to A, B occupies the chief place within the psychological question might be raised, his sphere of consciousness; he is at preswhether, in the mind of one who argues ent remembering B. Clearly then, unless from particulars to particulars, there is not some other cause interferes, the infánt will always a moment (mostly forgotten after- not merely remember B; he will also exwards) when both particulars as particulars pect B to happen in the concrete, immediare lost, and the points common to both ately. And in fact, at this stage, his realone come into prominence. Certain it is membrance of B as a past event will not that, in arguing from particulars to particu- be distinguishable from his expectation of lars, we often forget the particular from B as a coming event; his memory, without which we argue; we draw a conclusion so some powerful cause to make him throw rapidly as to forget not merely the argu- back B into that past time in which he first ment, but the very facts which form the observed it, will be swallowed up in his expremises. So that it may seein not im- pectation. Here then, at the outset of conprobable that the actual moment of transi- sciousness, we have the two laws of association from particular to particular is forgot- tion of ideas, and substitution of similarsten afterwards.
the psychological and logical laws—actually No student of psychology can fail to no coinciding in their effects. But let us conduct tice the analogy between this logical theory the analysis a little further. The infant, as of “the substitution of similars” and the we left him, was observing A (for the second psychological theory of the association of time) and expecting B. Now suppose B acideas." The difference is that, while the tually to happen this second time. Then the psychological theory affirms merely that expectation of B will be merged in the obwhen two thoughts have been frequently servation of it; there will be no sharp line presented together to the mind the recur- drawn between the two; indeed, memory
, exrence of one (whether in the shape of ob- pectation, observation, will all three as yet servation or memory) tends to make the be indistinguishable in the infant's mind
. other recur simultaneously, the logical the- But now suppose A to happen a third time, ory affirms that, when two facts have been and to be observed by the infant, who will frequently presented to the observation to then have the memory, and at the same time gether, the recurrence of the one tends to the expectation, of B forced upon him even create an expectation of the recurrence of more strongly than on the previous the other. But the two theories are un- sion (from the repetition). But suppose, doubtedly very near akin at their origin; this third tiine, that which succeeds A in and it may be useful to show how they are the observation of the infant to be not B, related to each other. Let us suppose then but C. Then (if B has by this time been an infant whose mind is just awakening to strongly enough impressed on his memory) the world around him, and has not yet a sense of antagonism will be aroused gained any grasp of facts and their se- within his consciousness : expecting B, he quences. Let us suppose two facts, A and will experience C. Thus while C impresses B, to pass successively, and to be observed itself most strongly on him, from its imby the infant. If, on another occasion, the mediate presence, B will still remain within fact A (that is, a fact precisely similar to his consciousness, in that A) recurs, and is observed by the infant, which we call memory. Here then, for the then by the law of association, the remem- first time, we have memory divorced from brance of the fact B, as observed on the observation; the psychological law of asso.