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43. Let us now see what Lord Bacon's method really He has given it the name of induction, Nature of but carefully distinguishes it from what bore that the Baco name in the old logic, that is, an inference from tion. a perfect enumeration of particulars to a general law of the whole. For such an enumeration, though of course conclusive, is rarely practicable in nature, where the particulars exceed our powers of numbering. Nor, again, is
* Inductio quæ procedit per enumerationem simplicem, res puerilis est, et precario concludit, et periculo exponitur ab instantia contradictoria, et plerumque secundum pauciora quam par est, et ex his tantummodo quæ præsto sunt pronuntiat. At inductio quæ ad inventionem et demonstrationem scientiarum et artium erit utilis, naturam separare debet, per rejectiones et exclusiones debitas; ac deinde post negativas tot quot sufficiunt, super affirmativas concludere; quod adhuc factum non est, nec tentatum certe, nisi tantummodo a Platone, qui ad excutiendas definitiones et ideas, hac certe forma inductionis aliquatenus utitur. Nov. Org., i. 105. In this passage Bacon seems to imply that the enumeration of particulars in any induction is or may be imperfect. This is certainly the case in the plurality of physical inductions; but it does not appear that the logical writers looked upon this as the primary and legitimate sense. Induction was distinguished into the complete and incomplete. "The word," says a very modern writer, " is perhaps unhappy, as indeed it is taken in several vague senses; but to abolish it is impossible. It is the Latin translation of zaywyn, which word is used by Aristotle as a counterpart to vaλoyous. He seems to consider it in a perfect or dialectic, and in an imperfect or rhetorical sense. Thus if a genus (G.) contained four species (A. B. C. D.), syllogism would argue, that what is true of G. is true of any one of the four; but perfect induction would reason, that what we can prove true of A. B. C. D. separately, we may properly state as true of G., the whole genus. This is evidently a formal argument, as demonstrative as syllogism. But the imperfect or rhetorical induction will perhaps enumerate three only of the species, and then draw the conclusion concerning G., which virtually includes the fourth, or, what is the same thing, will argue, that
what is true of the three is to be believed true likewise of the fourth." Newman's Lectures on Logic, p. 73 (1837). The same distinction between perfect and imperfect induction is made in the Encyclopédie Françoise, art. Induction, and apparently on the authority of the ancients.
It may be observed, that this imperfect induction may be put in a regular logical form, and is only vicious in syllogistic reasoning when the conclusion asserts a higher probability than the premises. If, for example, we reason thus: Some serpents are venomous.-This unknown animal is a serpent.-Therefore this is venomous; we are guilty of an obvious paralogism. If we infer only, This may be venomous, our reasoning is perfectly valid in itself, at least in the common apprehension of all mankind, except dialecticians, but not regular in form. The only means that I perceive of making it so, is to put it in some such phrase as the following: All unknown serpents are affected by a certain probability of being venomous: This animal, &c. It is not necessary, of course, that the probability should be capable of being estimated, provided we mentally conceive it to be no other in the conclusion than in the major term. In the best treatises on the strict or syllogistic method, as far as I have seen, there seems a deficiency in respect to probable conclusions, which may have arisen from the practice of taking instances from universal or necessary, rather than contingent truths, as well as from the contracted views of reasoning which the Aristotelian school have always inculcated. No sophisms are so frequent in practice as the concluding generally from a partial induction, or assuming (most commonly tacitly) by what Archbishop Whately calls" a kind of logical fiction," that a few individuals are " adequate samples or representations of the class they belong to." These sophisms cannot, in the present state of things, be practised
the Baconian method to be confounded with the less complete form of the inductive process, namely, inferences from partial experience in similar circumstances; though this may be a very sufficient ground for practical, which
largely in physical science or natural history; but in reasonings on matter of fact they are of incessant occurrence. The "logical fiction" may indeed frequently be employed, even on subjects unconnected with the physical laws of nature; but to know when this may be, and to what extent, is just that which, far more than any other skill, distinguishes what is called a good reasoner from a bad one. [I permit this note to remain as in former editions; but it might have been more fully and more correctly expressed. The proper nature of induction has been treated within a few years by Sir William Hamilton (Edinburgh Review, vol. Ivii.), by Archbishop Whately in his Elements of Logic, by the author of the article Organon" in the Penny Cyclopædia, by M. de Rémusat, Essais de Philosophie, vol. ii. p. 408, by Dr. Whewell in the "History," and again in the "Philosophy, of the Inductive Sciences," and by Mr. Mill, System of Logic, vol. i. p. 352. The apparently various opinions of these writers, though in some degree resolving themselves into differences of definition, deserve attention from the philosophical reader; but it would be rather too extraneous from the character of the present work to examine them. I will only observe, that what has been called perfect induction, or a complete enumeration of particulars, is as barren of new truth as the syllogism itself, to which indeed, though with some variety in the formal rules, it properly belongs. For if we have already enumerated all species of fish, and asserted them to be cold-blooded, we advance not a step by saying this again of a herring or a haddock. Mr. Mill, therefore, has well remarked, that " Induction is a process of inference; it proceeds from the known to the unknown; and any operation involving no inference, any process in which what seems the conclusion is no wider than the premises from which it is drawn, does not fall within the meaning of the term."-System of Logic, vol. i. p. 352. But this inference is only rendered logically conclusive, or satisfactory to the reason, as any thing more than a probable argument, by means of a generalisation, which assumes, on some extra
logical ground, such as the uniformity of physical laws, that the partial induction might have been rendered universal. If the conclusion contains more than the premises imply, it is manifestly fallacious. But that the inductive syllogism, ἐπαγωγῆς συλλογισμός (Analyt. Prin, l. ii. c. 23), can only lead, in form, to probable conclusions, even though the enumeration should be complete, appears from its being in the third figure, though after a general principle is once established by induction, when we come to apply it in new cases, the process will be in the first. Archbishop Whately and Sir W. Hamilton only differ in appearance as to this, since they look to different periods of reasoning; one, in which experience is generalised by the assumption of something unproved; another, in which a particular case is shown to fall within the generalisation. But the second is not the induction of Aristotle. What this was, I find no where more neatly delivered than in an Arabic treatise on logic, published, with a translation, in the eighth volume of the Asiatic Researches.
"Induction is the process of collecting particulars for the purpose of establishing a general rule respecting the nature of the whole class. Induction is of two kinds, viz. perfect and imperfect. It is perfect induction when the general rule is obtained from an examination of all the parts. For example, all animals are either endowed with speech, or not endowed with speech. But those endowed and those not endowed are both sentient; therefore all animals are sentient. This is an example of perfect induction, which produces certainty.
"It is imperfect induction when a number of individuals of a class being overlooked or excluded, a general rule is thus established respecting the whole. For instance, if it should be assumed that all animals move the under-jaw in eating, because this is the case with man, horses, goats, and sheep, this would be an example of imperfect induction, which does not afford certainty, because it is possible that some animals may not move the under-jaw in eating, as it is reported of the crocodile." p. 127.-1847.]
is probable, knowledge. His own method rests on the same general principle, namely, the uniformity of the laws of nature, so that in certain conditions of phænomena the same effects or the same causes may be assumed; but it endeavours to establish these laws on a more exact and finer process of reasoning than partial experience can effect. For the recurrence of antecedents and consequents does not prove a necessary connexion between them, unless we can exclude the presence of all other conditions which may determine the event. Long and continued experience of such a recurrence, indeed, raises a high probability of a necessary connexion; but the aim of Bacon was to supersede experience in this sense, and to find a shorter road to the result; and for this his methods of exclusion are devised. As complete and accurate a collection of facts, connected with the subject of inquiry, as possible, is to be made out by means of that copious natural history which he contemplated, or from any other good sources. These are to be selected, compared, and scrutinised, according to the rules of natural interpretation delivered in the second book of the Novum Organum, or such others as he designed to add to them; and if experiments are admissible, these are to be conducted according to the same rules. Experience and observation are the guides through the Baconian philosophy, which is the handmaid and interpreter of nature. When Lord Bacon seems to decry experience, which in certain passages he might be thought to do, it is the particular and empirical observation of individuals, from which many rash generalizations had been drawn, as opposed to that founded on an accurate natural history. Such hasty inferences he reckoned still more pernicious to true knowledge than the sophistical methods of the current philosophy; and in a remarkable passage, after censuring this precipitancy of empirical conclusions in the chemists, and in Gilbert's Treatise on the Magnet, utters a prediction that if ever mankind, excited by his counsels, should seriously betake themselves to seek the guidance of experience, instead of relying on the dogmatic schools of the sophists, the proneness of the human mind to snatch at general axioms would
expose them to much risk of error from the theories of this superficial class of philosophers.1
44. The indignation, however, of Lord Bacon is more His dislike frequently directed against the predominant of Aristotle. philosophy of his age, that of Aristotle and the schoolmen. Though he does justice to the great abilities of the former, and acknowledges the exact attention to facts displayed in his History of Animals, he deems him one of the most eminent adversaries to the only method that can guide us to the real laws of nature. The old Greek philosophers, Empedocles, Leucippus, Anaxagoras, and others of their age, who had been in the right track of investigation, stood much higher in the esteem of Bacon than their successors, Plato, Zeno, Aristotle, by whose lustre they had been so much superseded, that both their works have perished, and their tenets are with difficulty collected. These more distinguished leaders of the Grecian schools were in his eyes little else than disputatious professors (it must be remembered that he had in general only physical science in his view) who seemed to have it in common with children, "ut ad garriendum prompti sint, generare non possint;" so wordy and barren was their mis-called wisdom.
His method much re
45. Those who object to the importance of Lord Bacon's precepts in philosophy that mankind. quired. have practised many of them immemorially, are rather confirming their utility than taking off much from their originality in any fair sense of that term. Every logical method is built on the common faculties of human nature, which have been exercised since the creation in discerning, better or worse, truth from falsehood, and inferring the unknown from the known. That men might have done this more correctly is manifest from the quantity of error into which, from want of reasoning well on what came before them, they have habitually fallen. In experimental philosophy, to which the more special rules of Lord Bacon are generally referred, there was a notorious want of that very process of reasoning which he has supplied.
1 Nov. Organ., lib. i. 64. It may be doubted whether Bacon did full justice to Gilbert.
It is more than probable, indeed, that the great physical philosophers of the seventeenth century would have been led to employ some of his rules, had he never promulgated them; but I believe they had been little regarded in the earlier period of science. It is also a very defective view of the Baconian method to look only at the experimental rules given in the Novum Organum. The preparatory steps of completely exhausting the natural history of the subject of inquiry by a patient and sagacious consideration of it in every light are at least of equal importance, and equally prominent in the inductive philosophy.
46. The first object of Lord Bacon's philosophical writings is to prove their own necessity, by giving an unfavourable impression as to the actual state of most sciences, in consequence of the prejudices of the human mind, and of the mistaken methods pursued in their cultivation. The second was to point out a better prospect for the future. One of these occupies the treatise De Augmentis, and the first book of the Novum Organum. The other, besides many anticipations in these, is partially detailed in the second book, and would have been more thoroughly developed in those remaining portions which the author did not complete. We shall now give a very short sketch of these two famous works, which comprise the greater part of the Baconian philosophy.
47. The Advancement of Learning is divided into two books only; the treatise De Augmentis into nine. Sketch of the The first of these, in the latter, is introductory, Augmentis. and designed to remove prejudices against the search after truth, by indicating the causes which had hitherto obstructed it. In the second book, he lays down his celebrated partition of human learning into history, poetry, and philosophy, according to the faculties of the mind respectively concerned in them, the memory, imagination, and reason. History is natural or civil, under the latter of which ecclesiastical and literary histories are comprised. These again fall into regular subdivisions;
It has been remarked, that the famous experiment of Pascal on the barometer by carrying it to a considerable VOL. II.
elevation, was "a crucial instance, one of