[194] 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 doss 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 moderate 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 επαγωγη, which word is used by Aristotle as a counterpart to συλλογισμος. 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 Whateley 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 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. This note will not, by an attentive reader, be thought inapposite to the text, or to some passages that will follow in the present chapter.
[195] Nov. Organ. lib. i. 64. It may be doubted whether Bacon did full justice to Gilbert.
His dislike of Aristotle. 44. The indignation, however, of Lord Bacon is more frequently directed against the predominant 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 his esteem 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 Bacon 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 miscalled wisdom.
His method much required. 45. Those who object to the importance of Lord Bacon’s precepts in philosophy that mankind 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. It is 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.[196] 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.
[196] It has been remarked, that the famous experiment of Pascal on the barometer, by carrying it to a considerable elevation, was “a crucial instance, one of the first, if not the very first on record in physics.” Herschel, p. 229.
Its objects. 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.
Sketch of the treatise De Augmentis. 47. The Advancement of Learning is divided into two books only; the treatise De Augmentis into nine. The first of these, in the latter, is introductory, and designed to remove prejudices against the search for 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.| History is natural or civil, under the latter of which ecclesiastical and literary histories are comprised. These again fall into regular subdivisions; all of which he treats in summary manner, and points out the deficiencies which ought to be supplied in many departments of history. |Poetry.| Poetry succeeds in the last chapter of the same book, but by confining that name to fictitious narrative, except as to the ornaments of style, which he refers to a different part of his subject, he much limited his views of that literature; even if it were true, as it certainly is not, that the imagination alone, in any ordinary use of the word, is the medium of poetical emotion. The word emotion indeed is sufficient to show that Bacon should either have excluded poetry altogether from his enumeration of sciences and learning, or taken into consideration other faculties of the soul than those which are merely intellectual.
Fine passage on poetry. 48. Stewart has praised with justice a short but beautiful paragraph concerning poetry (under which title may be comprehended all the various creations of the faculty of imagination) wherein Bacon “has exhausted everything that philosophy and good sense have yet had to offer on the subject of what has since been called the beau idéal.” The same eminent writer and ardent admirer of Bacon observes that D’Alembert improved on the Baconian arrangement by classing the fine arts with poetry. Injustice had been done to painting and music, especially the former, when, in the fourth book De Augmentis, they were counted as mere “artes voluptariæ,” subordinate to a sort of Epicurean gratification of the senses, and only somewhat more liberal than cookery or cosmetics.
Natural Theology and Metaphysics. 49. In the third book, science having been divided into theological and philosophical, and the former, or what regards revealed religion, being postponed for the present, he lays it down that all philosophy relates to God, to nature, or to man. Under natural theology, as a sort of appendix, he reckons the doctrine of angels and superhuman spirits; a more favourite theme, especially as treated independently of revelation, in the ages that preceded Lord Bacon, than it has been since. Natural philosophy is speculative or practical; the former divided into physics, in a particular sense, and metaphysics; “one of which enquireth and handleth the material and efficient causes; the other handleth the formal and final causes.” Hence, physics dealing with particular instances, and regarding only the effects produced, is precarious in its conclusions, and does not reach the stable principles of causation.