[211] A calculation was published not long since, said to be on the authority of an eminent living philosopher, according to which, granting a moderate probability that each of twelve jurors would decide rightly, the chances in favour of the rectitude of their unanimous verdict were made something extravagantly high, I think about 8000 to 1. It is more easy to perceive the the fallacies of this pretended demonstration, than to explain how a man of great acuteness should have overlooked them. One among many is that it assumes the giving a verdict at all to be voluntary, whereas, in practice, the jury must decide one way or the other. We must deduct, therefore, a fraction expressing the probability that some of the twelve have wrongly conceded their opinions to the rest. One danger of this rather favourite application of mathematical principles to moral probabilities, as indeed it is of statistical tables (a remark of far wider extent), is that, by considering mankind merely as units, it practically habituates the mind to a moral and social levelling, as inconsistent with a just estimate of men as it is characteristic of the present age.
Result of the whole. 74. It seems upon the whole that we should neither conceive the inductive method to be useless in regard to any subject but physical science, nor deny the peculiar advantages it possesses in those inquiries rather than others. What must in all studies be important, is the habit of turning round the subject of our investigation in every light, the observation of everything that is peculiar, the exclusion of all that we find on reflection to be extraneous. In historical and antiquarian researches, in all critical examination which turns upon facts, in the scrutiny of judicial evidence, a great part of Lord Bacon’s method, not, of course, all the experimental rules of the Novum Organum, has, as I conceive, a legitimate application.[212] I would refer any one who may doubt this to his History of Winds, as one sample of what we mean by the Baconian method, and ask whether a kind of investigation, analogous to what is therein pursued for the sake of eliciting physical truths, might not be employed in any analytical process where general or even particular facts are sought to be known. Or if an example is required of such an investigation, let us look at the copious induction from the past and actual history of mankind upon which Malthus established his general theory of the causes which have retarded the natural progress of population. Upon all these subjects before-mentioned, there has been an astonishing improvement in the reasoning of the learned, and perhaps of the world at large since the time of Bacon, though much remains very defective. In what degree it may be owing to the prevalence of a physical philosophy founded upon his inductive logic, it might not be uninteresting to inquire.[213]
[212] The principle of Bacon’s prerogative instances, and perhaps in some cases a very analogous application of them, appear to hold in our inquiries into historical evidence. The fact sought to be ascertained in the one subject corresponds to the physical law in the other. The testimonies, as we, though rather laxly, call them, or passages in books from which we infer the fact, correspond to the observations or experiments from which we deduce the law. The necessity of a sufficient induction by searching for all proof that may bear on the question, is as manifest in one case as in the other. The exclusion of precarious and inconclusive evidence is alike indispensable in both. The selection of prerogative instances, or such as carry with them satisfactory conviction, requires the same sort of inventive and reasoning powers. It is easy to illustrate this by examples. Thus, in the controversy concerning the Icon Basilike, the admission of Gauden’s claim by Lord Clarendon is in the nature of a prerogative instance; it renders the supposition of the falsehood of that claim highly improbable. But the many second hand and hearsay testimonies which may be alleged on the other side, to prove that the book was written by King Charles, are not prerogative instances, because their falsehood will be found to involve very little improbability. So, in a different controversy, the silence of some of the fathers as to the text, commonly called, of the three heavenly witnesses, even while expounding the context of the passage, is a quasi-prerogative instance; a decisive proof that they did not know it, or did not believe it genuine; because if they did, no motive can be conceived for the omission. But the silence of Laurentius Valla as to its absence from the manuscripts on which he commented, is no prerogative instance to prove that it was contained in them; because it is easy to perceive that he might have motives for saying nothing; and, though the negative argument, as it is called, or inference that a fact is not true, because such and such persons have not mentioned it, is, taken generally, weaker than positive testimony, it will frequently supply prerogative instances where the latter does not. Launoy, in a little treatise, De Auctoritate Negantis Argumenti, which displays more plain sense than ingenuity or philosophy, lays it down that a fact of a public nature, which is not mentioned by any writer within 200 years of the time, supposing, of course, that there is extant a competent number of writers who would naturally have mentioned it, is not to be believed. The period seems rather arbitrary, and was possibly so considered by himself; but the general principle is of the highest importance in historical criticism. Thus, in the once celebrated question of Pope Joan, the silence of all writers near the time as to so wonderful a fact, was justly deemed a kind of prerogative argument, when set in opposition to the many repetitions of the story in later ages. But the silence of Gildas and Bede as to the victories of Arthur is no such argument against their reality, because they were not under an historical obligation, or any strong motive, which would prevent their silence. Generally speaking, the more anomalous and interesting an event is, the stronger is the argument against its truth from the silence of contemporaries, on account of the propensity of mankind to believe and recount the marvellous; and the weaker is the argument from the testimony of later times for the same reason. A similar analogy holds also in jurisprudence. The principle of our law, rejecting hearsay and secondary evidence, is founded on the Baconian rule. Fifty persons may depose that they have heard of a fact or of its circumstances; but the eye-witness is the prerogative instance. It would carry us too far to develop this at length, even if I were fully prepared to do so; but this much may lead us to think, that whoever shall fill up that lamentable desideratum, the logic of evidence, ought to have familiarised himself with the Novum Organum.
[213] “The effects which Bacon’s writings have hitherto produced, have indeed been far more conspicuous in physics than in the science of mind. Even here, however, they have been great and most important, as well as in some collateral branches of knowledge, such as natural jurisprudence, political economy, criticism and morals, which spring up from the same root, or rather which are branches of that tree of which the science of mind is the trunk.” Stewart’s Philosophical Essays, Prelim. Dissertation. The principal advantage, perhaps, of those habits of reasoning which the Baconian methods, whether learned directly or through the many disciples of that school, have a tendency to generate, is that they render men cautious and painstaking in the pursuit of truth, and therefore restrain them from deciding too soon. Nemo reperitur qui in rebus ipsis et experientia moram fecerit legitimam. These words are more frequently true of moral and political reasoners than of any others. Men apply historical or personal experience, but they apply it hastily, and without giving themselves time for either a copious or an exact induction; the great majority being too much influenced by passion, party-spirit, or vanity, or perhaps by affections morally right, but not the less dangerous in reasoning, to maintain the patient and dispassionate suspense of judgment (ακαταληψια), which ought to be the condition of our enquiries.
Bacon’s aptitude for moral subjects. 75. It is probable that Lord Bacon never much followed up in his own mind that application of his method to psychological, and still less to moral and political subjects, which he has declared himself to intend. The distribution of the Instauratio Magna, which he has prefixed to it, relates wholly to physical science. He has in no one instance given an example, in the Novum Organum, from moral philosophy, and one only, that of artificial memory, from what he would have called logic.[214] But we must constantly remember that the philosophy of Bacon was left exceedingly incomplete. Many lives would not have sufficed for what he had planned, and he gave only the horæ subsecivæ of his own. It is evident that he had turned his thoughts to physical philosophy rather for an exercise of his reasoning faculties, and out of his insatiable thirst for knowledge, than from any peculiar aptitude for their subjects, much less any advantage of opportunity for their cultivation. He was more eminently the philosopher of human, than of general nature. Hence, he is exact as well as profound in all his reflections on civil life and mankind, while his conjectures in natural philosophy, though often very acute, are apt to wander far from the truth in consequence of his defective acquaintance with the phænomena of nature. His Centuries of Natural History give abundant proof of this. He is, in all these inquiries, like one doubtfully, and by degrees, making out a distant prospect, but often deceived by the haze. But if we compare what may be found in the sixth, seventh, and eighth books De Augmentis, in the Essays, the History of Henry VII., and the various short treatises contained in his works, on moral and political wisdom, and on human nature, from experience of which all such wisdom is drawn, with the Rhetoric, Ethics, and Politics of Aristotle, or with the historians most celebrated for their deep insight into civil society and human character, with Thucydides, Tacitus, Philip de Comines, Machiavel, Davila, Hume, we shall, I think, find that one man may almost be compared with all of these together. When Galileo is named as equal to Bacon, it is to be remembered that Galileo was no moral or political philosopher, and in this department Leibnitz certainly falls very short of Bacon. Burke, perhaps, comes, of all modern writers, the nearest to him; but though Bacon may not be more profound than Burke, he is still more copious and comprehensive.
[214] Nov. Organ. ii. 26. It may however be observed, that we find a few passages in the ethical part of De Augmentis, lib. vii. cap. 3, which show that he had some notions of moral induction germinating in his mind.
Comparison of Bacon and Galileo. 76. The comparison of Bacon and Galileo is naturally built upon the influence which, in the same age they exerted in overthrowing the philosophy of the schools, and in founding that new discipline of real science which has rendered the last centuries glorious. Hume has given the preference to the latter, who made accessions to the domain of human knowledge so splendid, so inaccessible to cavil, so unequivocal in their results, that the majority of mankind would perhaps be carried along with this decision. There seems however to be no doubt that the mind of Bacon was more comprehensive and profound. But these comparisons are apt to involve incommensurable relations. In their own intellectual characters, they bore no great resemblance to each other. Bacon had scarce any knowledge of geometry, and so far ranks much below not only Galileo, but Descartes, Newton, and Leibnitz, all signalised by wonderful discoveries in the science of quantity, or in that part of physics which employs it. He has, in one of the profound aphorisms of the Novum Organum, distinguished the two species of philosophical genius, one more apt to perceive the differences of things, the other their analogies. In a mind of the highest order neither of these powers will be really deficient, and his own inductive method is at once the best exercise of both, and the best safeguard against the excess of either. But upon the whole, it may certainly be said, that the genius of Lord Bacon was naturally more inclined to collect the resemblances of nature than to note her differences. This is the case with men like him of sanguine temper, warm fancy, and brilliant wit; but it is not the frame of mind which is best suited to strict reasoning.
77. It is no proof of a solid acquaintance with Lord Bacon’s philosophy, to deify his name as the ancient schools did those of their founders, or even to exaggerate the powers of his genius. Powers they were surprisingly great, yet limited in their range, and not in all respects equal; nor could they overcome every impediment of circumstance. Even of Bacon it may be said, that he attempted more than he has achieved, and perhaps more than he clearly apprehended. His objects appear sometimes indistinct, and I am not sure that they are always consistent. In the Advancement of Learning, he aspired to fill up, or at least to indicate, the deficiencies in every department of knowledge, he gradually confined himself to philosophy, and at length to physics. But few of his works can be deemed complete, not even the treatise De Augmentis, which comes nearer to it than most of the rest. Hence, the study of Lord Bacon is difficult and not, as I conceive, very well adapted to those who have made no progress whatever in the exact sciences, nor accustomed themselves to independent thinking. They have never been made a textbook in our universities; though after a judicious course of preparatory studies, by which I mean a good foundation in geometry and the philosophical principles of grammar, the first book of the Novum Organum might be very advantageously combined with the instruction of an enlightened lecturer.[215]
[215] It by no means is to be inferred, that because the actual text of Bacon is not always such as can be well understood by very young men, I object to their being led to the real principles of inductive philosophy, which alone will teach them to think, firmly but not presumptuously, for themselves. Few defects, on the contrary, in our system of education are more visible than the want of an adequate course of logic; and this is not likely to be rectified so long as the Aristotelian methods challenge that denomination exclusively of all other aids to the reasoning faculties. The position that nothing else is to be called logic, were it even agreeable to the derivation of the word, which it is not, or to the usage of the ancients, which is by no means uniformly the case, or to that of modern philosophy and correct language, which is certainly not at all the case, is no answer to the question, whether what we call logic does not deserve to be taught at all.
A living writer of high reputation, who has at least fully understood his own subject, and illustrated it better than his predecessors from a more enlarged reading and thinking, wherein his own acuteness has been improved by the writers of the Baconian school, has been unfortunately instrumental, by the very merits of his treatise on Logic, in keeping up the prejudices on this subject, which have generally been deemed characteristic of the university to which he belonged. All the reflection I have been able to give to the subject has convinced me of the inefficacy of the syllogistic art in enabling us to think rightly for ourselves, or, which is part of thinking rightly, in detecting those fallacies of others which might impose on our understanding before we have acquired that art. It has been often alleged, and, as far as I can judge, with perfect truth, that no man, who can be worth answering, ever commits, except through mere inadvertence, any paralogisms which the common logic serves to point out. It is easy enough to construct syllogisms which sin against its rules; but the question is, by whom they were employed. It is not uncommon, as I am aware, to represent an adversary as reasoning illogically; but this is generally effected by putting his argument into our own words. The great fault of all, over-induction, or the assertion of a general premise upon an insufficient examination of particulars, cannot be discovered or cured by any logical skill; and this is the error into which men really fall, not that of omitting to distribute the middle term, though it comes in effect, and often in appearance, to the same thing. I do not contend that the rules of syllogism, which are very short and simple, ought not to be learned; or that there may not be some advantage in occasionally stating our own argument, or calling on another to state his, in a regular form (an advantage, however, rather dialectical, which is, in other words, rhetorical, than one which affects the reasoning faculties themselves): nor do I deny that it is philosophically worth while to know that all general reasoning by words may be reduced into syllogism, as it is to know that most of geometry may be resolved into the superposition of equal triangles; but to represent this portion of logical science as the whole, appears to me almost like teaching the scholar Euclid’s axioms, and the axiomatic theorem to which I have alluded, and calling this the science of geometry. The following passage from the Port-Royal logic is very judicious and candid, giving as much to the Aristotelian system as it deserves: “Cette partie, que nous avons maintenant à traiter, qui comprend les règles du raisonnement, est estimée la plus importante de la logique, et c’est presque l’unique qu’on y traite avec quelque soin; mais il y a sujet de douter si elle est aussi utile qu’on se l’imagine. La plupart des erreurs des hommes, comme nous avons déjà dit ailleurs, viennent bien plus de ce qu’ils raisonnent sur de faux principes, que non pas de ce qu’ils raisonnent mal suivant leurs principes. Il arrive rarement qu’on se laisse tromper par des raisonnemens qui ne soient faux que parce que la conséquence en est mal tirée; et ceux qui ne seroient pas capables d’en reconnoître la fausseté par la seule lumière de la raison, ne le seroient pas ordinairement d’entendre les règles que l’on en donne, et encore moins de les appliquer. Néanmoins, quand on ne considéreroit ces règles que comme des vérités spéculatives, elles serviroient toujours à exercer l’esprit; et de plus, on ne peut nier qu’elles n’aient quelque usage en quelques rencontres, et à l’égard de quelques personnes, qui, étant d’un naturel vif et pénétrant, ne se laissent quelquefois tromper par des fausses conséquences, que faute d’attention, à quoi la réflexion qu’ils feroient sur ces règles, seroit capable de remédier.” Art de Penser, part iii. How different is this sensible passage from one quoted from some anonymous writer in Whateley’s Logic, p. 34. “A fallacy consists of an ingenious mixture of truth and falsehood so entangled, so intimately blended, that the fallacy is, in the chemical phrase, held in solution one drop of sound logic is that test which immediately disunites them, makes the foreign substance visible, and precipitates it to the bottom.” One fallacy, it might be answered, as common as any, is the false analogy the misleading the mind by a comparison, where there is no real proportion or resemblance. The chemist’s test is the necessary means of detecting the foreign substance; if the “drop of sound logic” be such, it is strange that lawyers, mathematicians, and mankind in general, should so sparingly employ it; the fact being notorious, that those most eminent for strong reasoning powers are rarely conversant with the syllogistic method. It is also well known, that these “intimately blended mixtures of truth and falsehood” deceive no man of plain sense. So much for the test.