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144.: TODD’S BOOK OF ANALYSIS EXAMINER, 19 FEB., 1832, PP. 115-17 - John Stuart Mill, The Collected Works of John Stuart Mill, Volume XXIII - Newspaper Writings August 1831 - October 1834 Part II [1831]

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The Collected Works of John Stuart Mill, Volume XXIII - Newspaper Writings August 1831 - October 1834 Part II, ed. Ann P. Robson and John M. Robson, Introduction by Ann P. Robson and John M. Robson (Toronto: University of Toronto Press, London: Routledge and Kegan Paul, 1986).

Part of: Collected Works of John Stuart Mill, in 33 vols.

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144.

TODD’S BOOK OF ANALYSIS

EXAMINER, 19 FEB., 1832, PP. 115-17

This article, reviewing the work of Tweedy John Todd (1789-1840), physician and medical writer, witnesses to Mill’s concurrent work on logic. The first item in the “Literary Examiner,” it is headed “The Book of Analysis, or, a New Method of Experience; whereby the Induction of the Novum Organon is made easy of application to Medicine, Physiology, Meteorology, and Natural History; to Statistics, Political Economy, Metaphysics, and the more complex departments of Knowledge. By Tweedy John Todd, M.D. Royal College of Physicians of London, &c. &c. [London:] Murray, 1831.” It is described in Mill’s bibliography as “A review of a work entitled ‘The Book of Analysis, or a New Method of Experience’ by Tweedy John Todd, Esq. M.D.—In the Examiner of 19th February 1832.” (MacMinn, p. 19.) It is listed as “Review of ‘The Book of Analysis, by T.J. Todd, M.D.’ ” and enclosed in square brackets in the Somerville College set of the Examiner.

this is not a quackish book, though it is a book with rather a quackish title. When we first read the solemn announcement of “a new method of experience,” we expected to find a scheme for superseding the five senses: but it is not so: the author proposes no method of experience, other than the good old mode of seeing, hearing, and feeling. What he has invented is a method, not of experience, but of recording and marshalling our experience, in order to show more clearly and certainly the conclusions to which it leads.

In spite of the air of pretension about the title-page, the author seems a modest, sensible man. Indeed, the seemingly ostentatious manner in which he connects his own name with the words Experience and Induction, evidently arises from no worse cause than his understanding those terms in a peculiar sense. Else, what can he mean by saying that Lord Bacon was the discoverer of induction? (P. 6.) Lord Bacon was not the inventor of eyes and ears. The first person who discovered that fire burns, found it out by induction. Experience, in the received language both of philosophy and of the world, means seeing and feeling; and induction, judging from what we see and feel. But in our author’s sense, the two words mean, not the operations themselves, but some contrivances of our own to help us in performing those operations.

Not to dwell longer on the title, however, but to speak of the work itself; Dr. Todd has the merit of perceiving clearly and strongly the imperfect condition in which those branches of knowledge mostly remain, wherein we are chiefly dependant upon mere observation; as compared with those in which we possess almost unlimited power of making experiments, that is, of producing at pleasure such new combinations of circumstances, as we have reason to think will afford us a further insight into the laws of nature. To feel this imperfection of our existing knowledge, as vividly and keenly as Dr. Todd does, is already no inconsiderable indication of a philosophic intellect. If all who profess to be thinkers, had barely reached this one point of attainment, the knowledge of our present ignorance—the mouths of nine-tenths of the noisy persons we meet with in the world, would be closed, and the remaining tenth would seriously bestir themselves to acquire knowledge, instead of spending their time in trying to persuade themselves and other people that they have already got it. There would be an end at once, for example, to those clamorous appeals we daily hear, on the most complicated questions of state policy, to what are termed facts, that is, to history and statistics, by men, the sum total of whose knowledge of facts in history and statistics (though perhaps clever, well-informed men) is like an insect’s knowledge of the great earth; and their inductions, very like an oyster’s conjectures of the laws which govern the universe.

Dr. Todd, seeing the little progress which has been made towards a sufficient induction in the sciences of mere observation, and how inadequate to most practical purposes our experience has hitherto been, or else how inadequately that experience has yet been turned to account; being also well read in the standard works on logic and metaphysics, and in particular, being profoundly versed in the Novum Organum; very laudably determined to do what lay in him towards following up Lord Bacon’s great enterprise, and be himself also, in some sort, a reformer in philosophy. And in what he has done, it would be unjust to deny that there is both merit and utility, though we much question its power to produce such great results as he seems partly to expect from it.

The investigation of nature, consists in ascertaining by experience what are the facts which constantly occur in conjunction with one another. Whatever be the phenomenon which is the subject of inquiry, we discover the law of that phenomenon, by ascertaining what are the circumstances which are invariably found to be present whenever it occurs.

Now, this being the case, Dr. Todd’s plan is as follows:—To note down carefully all the circumstances of all the instances, or experiments, and arrange them in tables; the form of which tables, aided by a system of signs rather ingeniously contrived, shows at once, and almost at a glance, what are the circumstances which have been found to occur together in all the instances, and what are those which have been found not to occur together at all, or not with any regularity. If this were done, Dr. Todd thinks that much valuable experience would be preserved which is now lost, and that all the various generalizations which can be legitimately drawn from the instances which have been examined, would appear by simply reading off the signs. The principle on which the process rests, we give in his own words:

To recapitulate; having by the first process, the classification by affirmative circumstances, arranged and assorted the circumstances of all the instances, and formed them into classes; and having, by the second process of exclusion, or classification by negative circumstances, rejected from the classes all such circumstances as are not found constantly to belong to them; the circumstances which remain of each class may be collected and arranged together. Not having been able, by the evidence of any instance or individual fact, to separate these circumstances from each other, or from their class, it is allowed to conclude that they are connected with each other by some natural relation, either as cause or effect of each other as causes of a common effect, or effects of a common cause.

(Pp. 37-8.)

There is no doubt that where the complication of the subject is such, that it is impossible for the mind to take in at once the whole range of the evidence which it has to examine and decide upon, it becomes indispensable to bring our experience into a more compact and manageable shape. The utility of synoptic tables, for this purpose, is well known. And, of the immense increase of power which may be obtained by a well-contrived method of abridged notation, we have a memorable example in algebra; without the aid of which, our knowledge of the properties of numbers could never have reached much beyond common arithmetic. Dr. Todd’s is a contrivance somewhat similar. And that some invention of this sort will one day be brought into common use, for registering and methodizing the logical results of any extensive and varied series of observations, appears to us extremely probable. We only doubt whether the logical operation itself, which this plan is intended to facilitate, is one from which any great discoveries in philosophy are likely to flow.

In fact, when we consider the past history of philosophy, we find that not one of the great truths which have changed the face of science, was discovered in the manner which Lord Bacon and the author before us have laid down, namely, by collating an immense variety of very complicated instances, until, in the midst of the apparently inextricable confusion, there manifested itself something like an invariable order, or law. This is altogether a mistaken view of the nature of philosophical discovery; and Lord Bacon has here proved a false prophet. All the great laws of nature, yet known, have been ascertained by the observation of a few very simple, and generally very familiar phenomena; under circumstances of little complication, where the result of the experiment was not found liable to vary at each repetition from the effect of other unknown causes; where, therefore, that constancy of co-existence or of sequence, which constitutes the law of nature, is visible without any cumbrous apparatus of comparison, such as Lord Bacon conceived, and as our author has attempted to realize. These simple laws having thus been first brought to light in the simple cases, it was afterwards found, that we had only to suppose the same laws to be in operation universally—and all the phenomena of the more complex cases, however perplexed and intricate they had at first appeared, were, without any difficulty, fully accounted for.

Thus, (to use an example at once the grandest and the most familiar) when Newton discovered the laws of the motions of the heavenly bodies, it was not by comparing and collating a long series of astronomical observations. His conclusions were even, in many respects, contrary to those which had seemed to result from the method of direct observation. He did indeed most carefully and scrupulously examine every fact which authentic observation had brought to light respecting the solar system; but he did so, not in order to educe a theory from these facts, but to ascertain whether they corresponded to a theory already framed. The three laws of motion, the law of gravitation, and that of the composition of forces, had been ascertained in an unerring manner, by the simplest and most familiar experience; but experience confined of course to this earth. It occurred to Newton, that by merely supposing that these same laws extended to the whole solar system, all those phenomena of the sun, moon, and planets, which had till then been considered of so peculiar and mysterious a nature, might possibly be explained. And so, upon examination, it turned out. And in consequence of this discovery, there is scarcely any other science at the present day so perfect as astronomy; although (and this is one of the remarkable circumstances) a science of pure observation; for all mankind could not make the sun or moon budge an inch from its place, by their united efforts. But if we had remained destitute of the Newtonian theory till we could deduce it by generalization from the observed phenomena of the heavens, we probably should never, even with the aid of our author’s tabulae inveniendi,1 have made any nearer approach to it than Kepler’s discoveries.2

We suspect that, when any more comprehensive views shall be arrived at, or any greater certainty shall hereafter be attained, in the sciences, physical, moral, or political, than we at present enjoy, it will be in some such way as Newton’s, rather than by the road which our author has taken so much pains in marking out. We can illustrate this by a recent and highly interesting example. Among the branches of knowledge which our author has pointed out as standing in most need of an improved method of induction, is Meteorology. Has he ever read Mr. Daniell’s admirable work on that subject?3 If he have, he must be aware in how low a state that distinguished natural philosopher found his science, if science it could be called in which not one leading principle was ascertained; and to how respectable a rank among the sciences he instantly raised it, by simply reversing the course theretofore pursued; no longer attempting a direct induction from the results of atmospheric observation, but starting from laws of nature previously ascertained under less intricate circumstances—namely, the laws of evaporation and condensation, the properties of elastic fluids, and especially those of air and aqueous vapour; and examining synthetically how many of the phenomena with which meteorology is conversant, these laws would suffice to explain. The result was, that he found he could explain them almost all; and there now remains a much smaller residuum of atmospheric phenomena yet unaccounted for, than almost any one had been inclined, à priori, to set down to the account of agents yet unknown.

Dr. Todd might have dissected meteorological observations without limit, and persevered till doomsday in “translating circumstances into signs,” before his “induction by classification” would have led him to such a result as this. [Pp. 24, 54.]

We regret that, instead of only giving blank forms, Dr. Todd has not presented us with a specimen of his art, by the actual analysis of some interesting set of instances. If he had done this, nothing, we think, could have prevented him from seeing how much less his method is capable of effecting than he imagines, towards removing the difficulties of induction. Suppose, for example (as Dr. Todd considers his plan peculiarly adapted to inquiries respecting the mind), that the subject of investigation were the formation of character, and the instances individual men and women: has Dr. Todd ever considered what would be implied in a complete enumeration of the circumstances of each instance? It would include the whole history of the life of each of the individuals. Suppose that the subject were politics, and the instances nations: has he calculated the number of square miles which his tables would cover? To begin with a single instance, as, for example, England: we should like to see Dr. Todd attempt the analysis of this instance. Every law on our statute-book, every decision of a judge, which has passed into a law; every book which is in the hands of our youth; every idea or opinion, every feeling, every habit of thought or of conduct, which prevails among our people or among any class of our people; all the natural qualities inherent in our soil, in our climate, in our geographical position; every invention we have produced in the useful, or every work of genius in the fine arts; the constitution of our schools, of our universities, of our corporations, of our learned societies, of our church; nay, even the personal character of every individual in every rank of life who has any character that can be properly termed his own: and in addition to this, all the thousand-and-one accidents which are daily happening, or have happened any day for the last thousand years, tending to modify more or less the relations in which we stand to one another, to other countries, and to external nature. All this would be but a part of the analysis of one single instance. We ask Dr. Todd whether he seriously believes that the certainty he desiderates can be attained in politics, by collating a few (and the world affords but a few) instances of such vast and unmanageable complication?

And, after all, Dr. Todd’s method, if it were practicable and fulfilled its ends, would afford no help towards resolving the most difficult part of the problem—namely, to know whether the induction is sufficient. This does not depend upon the mere number of the instances. For it is evident that we should learn much more of the nature of animals, for instance, by examining one quadruped, one bird, and one fish, than by examining a hundred sparrows or a hundred eels.

Yet such methods as Dr. Todd’s are of very considerable use. Though they may never directly lead to scientific knowledge, they often, on subjects of empirical and probable evidence, afford an approximation to it, sufficient to be of practical use. They afford data for what is called the calculation of chances. The best knowledge we have, is often merely knowledge that certain things happen more frequently than not; without our being able to perceive in what circumstances the cases of exception differ from those which constitute the rule. Now, any process which methodises the substance of any great number of observed cases, and reduces them within moderate compass, attracts attention to combinations which had not before been suspected to be other than casual, and the knowledge of which, besides being of use for the guidance of conduct, probably suggests experiments which in time may bring to light a general law. Dr. Todd’s tables and system of signs seem not ill adapted to be of this kind of use. They will show, no doubt, in very many cases, that some conjunctions of circumstances take place more frequently than others—when, from the vastness and intricacy of the field of observation, this had not before been perceived. And medicine, Dr. Todd’s own subject, being one of those in which mankind have hitherto been least successful in discovering general laws, and are obliged to rely most on empirical observation; Dr. Todd’s method, by extending the range of such observation, may contribute to the enlargement of our knowledge and the increase of our power, in a degree sufficient to entitle its author to considerable gratitude, and his name to lasting remembrance.

[1 ]Todd’s Chapter i is headed, “Of a New Method of Induction, Performed by TabulaeInveniendi.” The term is taken from Bacon’s Novum Organum (1620), in The Works of Francis Bacon, ed. James Spedding, et al., 14 vols. (London: Longman, et al., 1857-74), Vol. I, p. 199 (Bk. I, Axiom cxii).

[2 ]The observations of Johann Kepler (1571-1630) were crucial to the development of Newton’s system.

[3 ]Meteorological Essays and Observations (London: Underwood, 1823), by John Frederick Daniell (1790-1845), reflects his concern for accurate records.