the work.

i. Partitiones Scientiarum: a summary or classification of Synopsis of all knowledge, with indications of those branches which have been more or less imperfectly treated. ii. Novum Organum: the New Instrument, an exposition of the methods to be adopted in the investigation of truth, with indications of the principal sources of human error, and the remedies against that error in future.

iii. Phænomena Universi, sive, Historia Naturalis et Experimentalis ad condendam Philosophiam: a complete body of well-observed facts and experiments in all branches of human knowledge, to furnish the raw material upon which the New Method was to be applied, in order to obtain results of truth.

iv. Scala Intellectus, sive, Filum Labyrinthi: rules for the gradual ascent of the mind from particular instances or phenomena, to principles continually more and more abstract; and warnings against the danger of proceeding otherwise than gradually and cautiously.

v. Prodromi, sive, Anticipationes Philosophiæ Secundæ : anticipations or forestallings of the New Philosophy, i.e. such truths as could be established, so to speak, provisionally, so as to be afterwards tested by the application of the New Method.

vi. Philosophia Secunda, sive, Scientia activa: the result of the just, careful, and complete application of the methods previously laid down to the vast body of facts to be accumulated and observed in accordance with the rules and precautions contained in the second and fourth parts.

Let us compare the position of Bacon, with respect to science in general, with that of an architect invited to undertake the reconstruction of a palace, ancient and splendid, but, Its logical in consequence of the lapse of time and changes in sequence. mode of living, found to be ruinous and uninhabitable. Under these circumstances an enlightened artist would make it his first care to draw an exact plan of the building in its present state, so as to form a clear notion of its extent, defects, and conveniences as it stands and not till then would he proceed to demolish the existing structure. He would next prepare such instruments, tools, and mechanical aids as would be likely to render his work of construction more rapid, certain, and economical. Thirdly, he would accumulate the necessary materials. Fourthly, he would provide the ladders. Lastly, he would begin to build; but, should the edifice be so vast that no human life would be long enough to terminate it, he would construct so much of it as would suffice to give his successors an idea of the general plan, style, and disposition of the parts, and leave it to be completed by future generations. It will easily be seen how accurately the mode of proceeding in Bacon's

great work corresponds with common-sense and with the method followed by our imaginary architect. Bacon is the builder; the great temple of knowledge is the edifice, which the labours of our race have finished according to his plan.

:

"In

$10. Let us now see what portion of this project Bacon was able to execute. The first part, consisting of a general view of the state of science in his time, with an explanation of the causes of its sterility and unprogressiveness, Beginnings of the " was published in 1605, and took the form of an stauratio." English treatise, bearing the title of The Proficience and Advancement of Learning this was afterwards much altered and extended, and was republished in Latin under the title De Augmentis Scientiarum (1623). The Novum Organum, the most important portion of Bacon's work, is that in which the necessity and the principles of the Inductive Method are laid down and demonstrated. It is, in short, the compendium of the Baconian logic. It was published, in Latin, in 1620. The fundamental difference between the The Induc method recommended by Bacon and that which had been so long adopted by philosophers, may, perhaps, be rendered clear by a

comparison of the accompanying little diagrams.

In the first of these the point A may be supposed to represent some general principle upon which depend any number of detached facts or phenomena B, C, D, E,

Deduction.

Synthesis.

A

à priori.

ARISTOTLE.

Induction.

tive Method.

Analysis.

A

à posteriori

and F. Now let it be B C D E F B C D E F G BACON. supposed that we are seeking for the explanation of one or all of these phenomena; or, in other words, are desirous of discovering the law upon which they depend. It is obvious that we may proceed as the arithmetician proceeds in the solution of a problem involving the search after an unknown quantity or numberthat is, we may suppose the law of nature to be so and so, and, by applying this law to one or all of the phenomena within our observation, see if it corresponds with them or not. If it does, we conclude, so far as our examination has extended, that we have hit upon the true result of which we are in search: if not, we must repeat the process, as the arithmetician would do in a like case, until we obtain an answer corresponding with all the conditions of the problem : and it is evident that, the greater the number of separate facts to which we successfully apply our theoretical explanation, the greater will be the probability of our having hit upon the true

ENG. LIT,

K

one. Now this application of a pre-established theory to particular facts or phenomena is precisely the signification of the word synthesis. It is obvious that the march of the mind in this mode of investigation is from the general to the particular —that is, in the direction of the arrow, or downwards-whence this mode of investigation is styled deduction, or a descent from the general law to the individual example. Similarly, the Aristotelian method has received the designation à priori, because in it the establishment, or, at all events, the provisional employment of a theory, is prior to its application in practice, just as in measuring an unknown space we previously establish a rule, as of a foot, yard, etc., which we afterwards apply to the space to be so determined. In the second diagram all the elements are the same as in the previous one, with the exception that here the process follows a precisely opposite direction-that is, from a careful comparison of the different facts the mind gradually travels upward, with slow and cautious advances, from bare phenomena to more general considerations, till it reaches some point in which all the phenomena agree; and this point is the law of nature or general principle of which we were in search. As synthesis signifies composition, so analysis signifies resolution: and it is by a continual and cautious process of resolution that the mind ascends in the direction marked by the arrow-from the particular to the general. This ascending process is chiefly indicated by the term induction, which signifies an ascent from particular instances to the general law; and the term à posteriori denotes that the theory, being evolved from the examination of the individual facts, is necessarily posterior or subsequent to the examination of those facts. All human inventions have their good and their bad sides, their advantages and defects: and it is only by a comparison between the relative advantages and defects that we can establish the superiority of one system or mode of action over another. On contemplating the two methods, of which the above is a very rough and popular explanation, it will be obvious at once that the deductive mode enables us, when we have hit upon the right theory, to arrive at absolute or almost mathematical truth; while analysis, being dependent for its accuracy upon the number of phenomena which furnish the material for our induction, can never arrive at absolute certainty, inasmuch as it is impossible to examine all the phenomena of a single class, and as, while any phenomena remain unexamined, we never can be certain that the discovery of some new fact will not completely overset our conclusions. The utmost, therefore, that we can arrive at by this route is a very high degree of probability-a degree which will be higher in proportion as it is founded upon a greater number of instances and attained by a more careful process of sifting. But the human mind is by nature practically incapable of distinguishing between a very high probability and an absolute

The à posteriori versus the à priori reasoning.

certainty at least, the first is able to produce upon the reason the same amount of conviction as an absolute certainty-and an amount, perhaps, even greater. If we consider, therefore, the enormous number of chances against the likelihood that any given à priori deduction is the right one-for, as in an arithmetical problem, there can be only one correct solution, while the number of possible incorrect solutions is infinite-and if we observe that, until all the possible phenomena have been submitted to the synthetic test we never can be sure that we have the right theory, we shall easily agree that the possible certainty of a theory is dearly bought when compared with the far greater safety of the analytical mode of reasoning, which, keeping fast hold of nature at each step of its progress, has the possibility, nay, even the certainty, of correcting its errors as they may arise.

The most important portion of the whole Instauratio is the Novum Organum, in which Bacon lays down the rules for the employment of the Inductive Method in investigating truth, and points out the origin and remedies of the The "Novum Organum." errors that most commonly oppose us in our search. The earlier philosophers, and particularly Aristotle, assigning a great and almost unlimited efficacy in this research to the intellectual faculties alone, contented themselves with perfecting those logical formulas, and, chief among them, the syllogism, by whose aid, as by the operation of some infallible instrument, they conceived that the result would surely be attained; and gave rules for the employment of their syllogism, pointing out the means of detecting and guarding against fallacies or irregularities in the expression of their reasoning. Bacon went far deeper than this, and showed that the most dangerous and universal sources of human error have their origin, not in the illegitimate employment of terms, but in the weaknesses, prejudices, and passions of mankind, exhibited either in the race or in the individual. He classifies these sources of error, which, in his vivid picturesque language, he calls Idols, or false appearances, in four categories; the idols of the Tribe, of the Den, of the Market-place, and of the The sources Theatre. Under the first head he warns us against of error, those errors and prejudices that are common to the whole race, the tribe to which we all belong; the idols of the Den are those which arise from the particular circumstances of the individual, as his country, his age, his religion, or his personal character; the errors of the Market-place are the result of the universal habit of using terms the meaning of which we have either not distinctly agreed on, or do not clearly understand. Such terms are used in the interchange of thought as money is passed from hand to hand in the market; and we accept and transfer to others coins whose real value we have not taken the trouble to test. The idols of the Theatre are the errors arising from false systems of philosophy, which dress up

or "Idols."

conceptions in unreal disguises, like comedians upon the stage. We may compare the precautions of the older logic to the methods of a physician who, directing his efforts to the external symptoms of a disorder, should think his duty performed when he had purified the skin, although at the probable cost of driving in the disease and rendering it twice as dangerous. Bacon, like a more enlightened doctor, sought out the deepseated constitutional source of the malady; and it was to this that he addressed his treatment, certain that when the internal cause was removed the symptoms would vanish of themselves. § 11. Of the Third Book, Bacon has given only a specimen, intended to show the method which should be adopted in

Later portions of the "Instauratio."

collecting and classifying facts and experiments; for in a careful examination of facts and experiments consists the whole essence of his induction, and in it are concealed the future destinies of human knowledge and power. This portion of the work contains a Latin history of the Winds (1622), of Life and Death (1623), and a collection of experiments in Physics, or, as he calls it, Natural History, written in English. This portion of the work alone is sufficient to show how slight are Bacon's claims or pretensions to the character of a discoverer in natural science, and how completely he was under the influence of the errors of his day; but, at the same time, it proves the innate merit of his method, and the power of that mind which could legislate for the whole realm of knowledge and for sciences yet unborn. To the English fragment he gives the title of Sylva Sylvarum, i.e. a collection of materials. This was published posthumously in 1627.

The Fourth Book, Scala Intellectus, of which Bacon left but a brief abstract, was intended to show the gradual march which ought to be followed by induction, in ascending from the fact perceptible to the senses to principles which are to become more and more general as we advance; and the author's object was to warn against the danger of leaping abruptly over the intermediate steps of the investigation. Of the Fifth Book, he wrote only a preface, and the Sixth was never begun.

§ 12. The best proof of the soundness and fertility of Bacon's methods is simple and practical. We have only to compare the

science.

progress of humanity in all the useful arts during the Bacon and two centuries and a half since induction has been generally employed in all branches of science, with the progress made during the twenty centuries that elapsed between Aristotle and Bacon. It is no exaggeration to say that in the shorter interval that progress has been ten times greater than in the longer. That this progress is in any degree to be attributed to any superiority of the modern intellect, is a supposition too unlimited to deserve a moment's attention. No human intellect has been more vast, more penetrating, and more active than that, not merely of Aristotle himself, but of philosopher after philosopher who wasted his powers in perfectly