This operation, which we have called analytical5, inasmuch as it is the resolution of a complex whole into the component6 elements, is more than a merely mental analysis. No mere7 contemplation of the phenomena, and partition of them by the intellect alone, will of itself accomplish the end we have now in view. Nevertheless, such a mental partition is an indispensable first step. The order of nature, as perceived at a first glance, presents at every instant a chaos8 followed by another chaos. We must decompose9 each chaos into single facts. We must learn to see in the chaotic10 antecedent a multitude of distinct antecedents, in the chaotic consequent a multitude of distinct consequents. This, supposing it done, [Pg 415]will not of itself tell us on which of the antecedents each consequent is invariably attendant. To determine that point, we must endeavour to effect a separation of the facts from one another, not in our minds only, but in nature. The mental analysis, however, must take place first. And every one knows that in the mode of performing it, one intellect differs immensely from another. It is the essence of the act of observing; for the observer is not he who merely sees the thing which is before his eyes, but he who sees what parts that thing is composed of. To do this well is a rare talent. One person, from inattention, or attending only in the wrong place, overlooks half of what he sees: another sets down much more than he sees, confounding it with what he imagines, or with what he infers; another takes note of the kind of all the circumstances, but being inexpert in estimating their degree, leaves the quantity of each vague and uncertain; another sees indeed the whole, but makes such an awkward division of it into parts, throwing things into one mass which require to be separated, and separating others which might more conveniently be considered as one, that the result is much the same, sometimes even worse, than if no analysis had been attempted at all. It would be possible to point out what qualities of mind, and modes of mental culture, fit a person for being a good observer: that, however, is a question not of Logic11, but of the Theory of Education, in the most enlarged sense of the term. There is not properly an Art of Observing. There may be rules for observing. But these, like rules for inventing, are properly instructions for the preparation of one's own mind; for putting it into the state in which it will be most fitted to observe, or most likely to invent. They are, therefore, essentially12 rules of self-education, which is a different thing from Logic. They do not teach how to do the thing, but how to make ourselves capable of doing it. They are an art of strengthening the limbs, not an art of using them.
The extent and minuteness of observation which may be requisite13, and the degree of decomposition14 to which it may be necessary to carry the mental analysis, depend on the particular purpose in view. To ascertain1 the state of the whole [Pg 416]universe at any particular moment is impossible, but would also be useless. In making chemical experiments, we do not think it necessary to note the position of the planets; because experience has shown, as a very superficial experience is sufficient to show, that in such cases that circumstance is not material to the result: and, accordingly, in the ages when men believed in the occult influences of the heavenly bodies, it might have been unphilosophical to omit ascertaining the precise condition of those bodies at the moment of the experiment. As to the degree of minuteness of the mental subdivision; if we were obliged to break down what we observe into its very simplest elements, that is, literally15 into single facts, it would be difficult to say where we should find them: we can hardly ever affirm that our divisions of any kind have reached the ultimate unit. But this too is fortunately unnecessary. The only object of the mental separation is to suggest the requisite physical separation, so that we may either accomplish it ourselves, or seek for it in nature; and we have done enough when we have carried the subdivision as far as the point at which we are able to see what observations or experiments we require. It is only essential, at whatever point our mental decomposition of facts may for the present have stopped, that we should hold ourselves ready and able to carry it farther as occasion requires, and should not allow the freedom of our discriminating16 faculty17 to be imprisoned18 by the swathes and bands of ordinary classification; as was the case with all early speculative19 inquirers, not excepting the Greeks, to whom it seldom occurred that what was called by one abstract name might, in reality, be several phenomena, or that there was a possibility of decomposing20 the facts of the universe into any elements but those which ordinary language already recognised.
§ 2. The different antecedents and consequents, being, then, supposed to be, so far as the case requires, ascertained21 and discriminated22 from one another; we are to inquire which is connected with which. In every instance which comes under our observation, there are many antecedents and many [Pg 417]consequents. If those antecedents could not be severed23 from one another except in thought, or if those consequents never were found apart, it would be impossible for us to distinguish (à posteriori at least) the real laws, or to assign to any cause its effect, or to any effect its cause. To do so, we must be able to meet with some of the antecedents apart from the rest, and observe what follows from them; or some of the consequents, and observe by what they are preceded. We must, in short, follow the Baconian rule of varying the circumstances. This is, indeed, only the first rule of physical inquiry24, and not, as some have thought, the sole rule; but it is the foundation of all the rest.
For the purpose of varying the circumstances, we may have recourse (according to a distinction commonly made) either to observation or to experiment; we may either find an instance in nature, suited to our purposes, or, by an artificial arrangement of circumstances, make one. The value of the instance depends on what it is in itself, not on the mode in which it is obtained: its employment for the purposes of induction25 depends on the same principles in the one case and in the other; as the uses of money are the same whether it is inherited or acquired. There is, in short, no difference in kind, no real logical distinction, between the two processes of investigation26. There are, however, practical distinctions to which it is of considerable importance to advert27.
§ 3. The first and most obvious distinction between Observation and Experiment is, that the latter is an immense extension of the former. It not only enables us to produce a much greater number of variations in the circumstances than nature spontaneously offers, but also, in thousands of cases, to produce the precise sort of variation which we are in want of for discovering the law of the phenomenon; a service which nature, being constructed on a quite different scheme from that of facilitating our studies, is seldom so friendly as to bestow28 upon us. For example, in order to ascertain what principle in the atmosphere enables it to sustain life, the variation we require is that a living animal should be immersed [Pg 418]in each component element of the atmosphere separately. But nature does not supply either oxygen or azote in a separate state. We are indebted to artificial experiment for our knowledge that it is the former, and not the latter, which supports respiration29; and for our knowledge of the very existence of the two ingredients.
Thus far the advantage of experimentation30 over simple observation is universally recognised: all are aware that it enables us to obtain innumerable combinations of circumstances which are not to be found in nature, and so add to nature's experiments a multitude of experiments of our own. But there is another superiority (or, as Bacon would have expressed it, another prerogative) of instances artificially obtained over spontaneous instances,—of our own experiments over even the same experiments when made by nature,—which is not of less importance, and which is far from being felt and acknowledged in the same degree.
When we can produce a phenomenon artificially, we can take it, as it were, home with us, and observe it in the midst of circumstances with which in all other respects we are accurately31 acquainted. If we desire to know what are the effects of the cause A, and are able to produce A by means at our disposal, we can generally determine at our own discretion32, so far as is compatible with the nature of the phenomenon A, the whole of the circumstances which shall be present along with it: and thus, knowing exactly the simultaneous state of everything else which is within the reach of A's influence, we have only to observe what alteration33 is made in that state by the presence of A.
For example, by the electric machine we can produce in the midst of known circumstances, the phenomena which nature exhibits on a grander scale in the form of lightning and thunder. Now let any one consider what amount of knowledge of the effects and laws of electric agency mankind could have obtained from the mere observation of thunder-storms, and compare it with that which they have gained, and may expect to gain, from electrical and galvanic experiments. This example is the more striking, now that we have [Pg 419]reason to believe that electric action is of all natural phenomena (except heat) the most pervading34 and universal, which, therefore, it might antecedently have been supposed could stand least in need of artificial means of production to enable it to be studied; while the fact is so much the contrary, that without the electric machine, the Leyden jar, and the voltaic battery, we probably should never have suspected the existence of electricity as one of the great agents in nature; the few electric phenomena we should have known of would have continued to be regarded either as supernatural, or as a sort of anomalies and eccentricities35 in the order of the universe.
When we have succeeded in insulating the phenomenon which is the subject of inquiry, by placing it among known circumstances, we may produce further variations of circumstances to any extent, and of such kinds as we think best calculated to bring the laws of the phenomenon into a clear light. By introducing one well-defined circumstance after another into the experiment, we obtain assurance of the manner in which the phenomenon behaves under an indefinite variety of possible circumstances. Thus, chemists, after having obtained some newly-discovered substance in a pure state, (that is, having made sure that there is nothing present which can interfere36 with and modify its agency,) introduce various other substances, one by one, to ascertain whether it will combine with them, or decompose them, and with what result; and also apply heat, or electricity, or pressure, to discover what will happen to the substance under each of these circumstances.
But if, on the other hand, it is out of our power to produce the phenomenon, and we have to seek for instances in which nature produces it, the task before us is very different. Instead of being able to choose what the concomitant circumstances shall be, we now have to discover what they are; which, when we go beyond the simplest and most accessible cases, it is next to impossible to do, with any precision and completeness. Let us take, as an exemplification of a phenomenon which we have no means of fabricating artificially, a human mind. Nature produces many; but the consequence [Pg 420]of our not being able to produce them by art is, that in every instance in which we see a human mind developing itself, or acting37 upon other things, we see it surrounded and obscured by an indefinite multitude of unascertainable circumstances, rendering38 the use of the common experimental methods almost delusive39. We may conceive to what extent this is true, if we consider, among other things, that whenever nature produces a human mind, she produces, in close connexion with it, a body; that is, a vast complication of physical facts, in no two cases perhaps exactly similar, and most of which (except the mere structure, which we can examine in a sort of coarse way after it has ceased to act), are radically40 out of the reach of our means of exploration. If, instead of a human mind, we suppose the subject of investigation to be a human society or State, all the same difficulties recur in a greatly augmented41 degree.
We have thus already come within sight of a conclusion, which the progress of the inquiry will, I think, bring before us with the clearest evidence: namely, that in the sciences which deal with phenomena in which artificial experiments are impossible (as in the case of astronomy), or in which they have a very limited range (as in mental philosophy, social science, and even physiology), induction from direct experience is practised at a disadvantage in most cases equivalent to impracticability: from which it follows that the methods of those sciences, in order to accomplish anything worthy42 of attainment43, must be to a great extent, if not principally, deductive. This is already known to be the case with the first of the sciences we have mentioned, astronomy; that it is not generally recognised as true of the others, is probably one of the reasons why they are not in a more advanced state.
§ 4. If what is called pure observation is at so great a disadvantage, compared with artificial experimentation, in one department of the direct exploration of phenomena, there is another branch in which the advantage is all on the side of the former.
Inductive inquiry having for its object to ascertain what [Pg 421]causes are connected with what effects, we may begin this search at either end of the road which leads from the one point to the other: we may either inquire into the effects of a given cause, or into the causes of a given effect. The fact that light blackens chloride of silver might have been discovered either by experiments on light, trying what effect it would produce on various substances, or by observing that portions of the chloride had repeatedly become black, and inquiring into the circumstances. The effect of the urali poison might have become known either by administering it to animals, or by examining how it happened that the wounds which the Indians of Guiana inflict44 with their arrows prove so uniformly mortal. Now it is manifest from the mere statement of the examples, without any theoretical discussion, that artificial experimentation is applicable only to the former of these modes of investigation. We can take a cause, and try what it will produce: but we cannot take an effect, and try what it will be produced by. We can only watch till we see it produced, or are enabled to produce it by accident.
This would be of little importance, if it always depended on our choice from which of the two ends of the sequence we would undertake our inquiries45. But we have seldom any option. As we can only travel from the known to the unknown, we are obliged to commence at whichever end we are best acquainted with. If the agent is more familiar to us than its effects, we watch for, or contrive46, instances of the agent, under such varieties of circumstances as are open to us, and observe the result. If, on the contrary, the conditions on which a phenomenon depends are obscure, but the phenomenon itself familiar, we must commence our inquiry from the effect. If we are struck with the fact that chloride of silver has been blackened, and have no suspicion of the cause, we have no resource but to compare instances in which the fact has chanced to occur, until by that comparison we discover that in all those instances the substances had been exposed to light. If we knew nothing of the Indian arrows but their fatal effect, accident alone could turn our attention to experiments on the urali; in the regular course of investigation, we could only [Pg 422]inquire, or try to observe, what had been done to the arrows in particular instances.
Wherever, having nothing to guide us to the cause, we are obliged to set out from the effect, and to apply the rule of varying the circumstances to the consequents, not the antecedents, we are necessarily destitute47 of the resource of artificial experimentation. We cannot, at our choice, obtain consequents, as we can antecedents, under any set of circumstances compatible with their nature. There are no means of producing effects but through their causes, and by the supposition the causes of the effect in question are not known to us. We have therefore no expedient48 but to study it where it offers itself spontaneously. If nature happens to present us with instances sufficiently49 varied50 in their circumstances, and if we are able to discover, either among the proximate antecedents or among some other order of antecedents, something which is always found when the effect is found, however various the circumstances, and never found when it is not; we may discover, by mere observation without experiment, a real uniformity in nature.
But though this is certainly the most favourable51 case for sciences of pure observation, as contrasted with those in which artificial experiments are possible, there is in reality no case which more strikingly illustrates52 the inherent imperfection of direct induction when not founded on experimentation. Suppose that, by a comparison of cases of the effect, we have found an antecedent which appears to be, and perhaps is, invariably connected with it: we have not yet proved that antecedent to be the cause, until we have reversed the process, and produced the effect by means of that antecedent. If we can produce the antecedent artificially, and if, when we do so, the effect follows, the induction is complete; that antecedent is the cause of that consequent.[32] But we have then added [Pg 423]the evidence of experiment to that of simple observation. Until we had done so, we had only proved invariable antecedence53 within the limits of experience, but not unconditional54 antecedence, or causation. Until it had been shown by the actual production of the antecedent under known circumstances, and the occurrence thereupon of the consequent, that the antecedent was really the condition on which it depended; the uniformity of succession which was proved to exist between them might, for aught we knew, be (like the succession of day and night) not a case of causation at all; both antecedent and consequent might be successive stages of the effect of an ulterior cause. Observation, in short, without experiment (supposing no aid from deduction) can ascertain sequences and coexistences, but cannot prove causation.
In order to see these remarks verified by the actual state of the sciences, we have only to think of the condition of natural history. In zoology55, for example, there is an immense number of uniformities ascertained, some of coexistence, others of succession, to many of which, notwithstanding considerable variations of the attendant circumstances, we know not any exception: but the antecedents, for the most part, are such as we cannot artificially produce; or if we can, it is only by setting in motion the exact process by which nature produces them; and this being to us a mysterious process, of which the main circumstances are not only unknown but unobservable, we do not succeed in obtaining the antecedents under known circumstances. What is the result? That on this vast subject, which affords so much and such varied scope for observation, we have made most scanty56 progress in ascertaining any laws of causation. We know not with certainty, in the case of most of the phenomena that we find conjoined, which is the condition of the other; which is cause, and which effect, or whether either of them is so, or they are not rather conjunct effects of causes yet to be discovered, complex results of laws hitherto unknown.
Although some of the foregoing observations may be, in technical strictness of arrangement, premature57 in this place, it seemed that a few general remarks on the difference between [Pg 424]sciences of mere observation and sciences of experimentation, and the extreme disadvantage under which directly inductive inquiry is necessarily carried on in the former, were the best preparation for discussing the methods of direct induction; a preparation rendering superfluous58 much that must otherwise have been introduced, with some inconvenience, into the heart of that discussion. To the consideration of these methods we now proceed.
点击
收听单词发音
收听单词发音 |
1
ascertain
|
|
| vt.发现，确定，查明，弄清 | |
参考例句： |
|
|
|
|
2
ascertaining
|
|
| v.弄清，确定，查明( ascertain的现在分词 ) | |
参考例句： |
|
|
|
|
3
phenomena
|
|
| n.现象 | |
参考例句： |
|
|
|
|
4
recur
|
|
| vi.复发，重现，再发生 | |
参考例句： |
|
|
|
|
5
analytical
|
|
| adj.分析的；用分析法的 | |
参考例句： |
|
|
|
|
6
component
|
|
| n.组成部分，成分，元件；adj.组成的，合成的 | |
参考例句： |
|
|
|
|
7
mere
|
|
| adj.纯粹的；仅仅，只不过 | |
参考例句： |
|
|
|
|
8
chaos
|
|
| n.混乱，无秩序 | |
参考例句： |
|
|
|
|
9
decompose
|
|
| vi.分解；vt.（使）腐败，（使）腐烂 | |
参考例句： |
|
|
|
|
10
chaotic
|
|
| adj.混沌的，一片混乱的，一团糟的 | |
参考例句： |
|
|
|
|
11
logic
|
|
| n.逻辑(学)；逻辑性 | |
参考例句： |
|
|
|
|
12
essentially
|
|
| adv.本质上，实质上，基本上 | |
参考例句： |
|
|
|
|
13
requisite
|
|
| adj.需要的，必不可少的；n.必需品 | |
参考例句： |
|
|
|
|
14
decomposition
|
|
| n. 分解, 腐烂, 崩溃 | |
参考例句： |
|
|
|
|
15
literally
|
|
| adv.照字面意义，逐字地；确实 | |
参考例句： |
|
|
|
|
16
discriminating
|
|
| a.有辨别能力的 | |
参考例句： |
|
|
|
|
17
faculty
|
|
| n.才能；学院，系；(学院或系的)全体教学人员 | |
参考例句： |
|
|
|
|
18
imprisoned
|
|
| 下狱，监禁( imprison的过去式和过去分词 ) | |
参考例句： |
|
|
|
|
19
speculative
|
|
| adj.思索性的，暝想性的，推理的 | |
参考例句： |
|
|
|
|
20
decomposing
|
|
| 腐烂( decompose的现在分词 )； （使）分解； 分解（某物质、光线等） | |
参考例句： |
|
|
|
|
21
ascertained
|
|
| v.弄清，确定，查明( ascertain的过去式和过去分词 ) | |
参考例句： |
|
|
|
|
22
discriminated
|
|
| 分别，辨别，区分( discriminate的过去式和过去分词 )； 歧视，有差别地对待 | |
参考例句： |
|
|
|
|
23
severed
|
|
| v.切断，断绝( sever的过去式和过去分词 )；断，裂 | |
参考例句： |
|
|
|
|
24
inquiry
|
|
| n.打听，询问，调查，查问 | |
参考例句： |
|
|
|
|
25
induction
|
|
| n.感应，感应现象 | |
参考例句： |
|
|
|
|
26
investigation
|
|
| n.调查，调查研究 | |
参考例句： |
|
|
|
|
27
advert
|
|
| vi.注意，留意，言及；n.广告 | |
参考例句： |
|
|
|
|
28
bestow
|
|
| v.把…赠与，把…授予；花费 | |
参考例句： |
|
|
|
|
29
respiration
|
|
| n.呼吸作用；一次呼吸；植物光合作用 | |
参考例句： |
|
|
|
|
30
experimentation
|
|
| n.实验，试验，实验法 | |
参考例句： |
|
|
|
|
31
accurately
|
|
| adv.准确地，精确地 | |
参考例句： |
|
|
|
|
32
discretion
|
|
| n.谨慎；随意处理 | |
参考例句： |
|
|
|
|
33
alteration
|
|
| n.变更，改变；蚀变 | |
参考例句： |
|
|
|
|
34
pervading
|
|
| v.遍及，弥漫( pervade的现在分词 ) | |
参考例句： |
|
|
|
|
35
eccentricities
|
|
| n.古怪行为( eccentricity的名词复数 )；反常；怪癖 | |
参考例句： |
|
|
|
|
36
interfere
|
|
| v.(in)干涉，干预；(with)妨碍，打扰 | |
参考例句： |
|
|
|
|
37
acting
|
|
| n.演戏，行为，假装；adj.代理的，临时的，演出用的 | |
参考例句： |
|
|
|
|
38
rendering
|
|
| n.表现，描写 | |
参考例句： |
|
|
|
|
39
delusive
|
|
| adj.欺骗的，妄想的 | |
参考例句： |
|
|
|
|
40
radically
|
|
| ad.根本地，本质地 | |
参考例句： |
|
|
|
|
41
Augmented
|
|
| adj.增音的 动词augment的过去式和过去分词形式 | |
参考例句： |
|
|
|
|
42
worthy
|
|
| adj.(of)值得的，配得上的；有价值的 | |
参考例句： |
|
|
|
|
43
attainment
|
|
| n.达到，到达；［常pl.］成就，造诣 | |
参考例句： |
|
|
|
|
44
inflict
|
|
| vt.(on)把…强加给，使遭受，使承担 | |
参考例句： |
|
|
|
|
45
inquiries
|
|
| n.调查( inquiry的名词复数 )；疑问；探究；打听 | |
参考例句： |
|
|
|
|
46
contrive
|
|
| vt.谋划，策划；设法做到；设计，想出 | |
参考例句： |
|
|
|
|
47
destitute
|
|
| adj.缺乏的；穷困的 | |
参考例句： |
|
|
|
|
48
expedient
|
|
| adj.有用的，有利的；n.紧急的办法，权宜之计 | |
参考例句： |
|
|
|
|
49
sufficiently
|
|
| adv.足够地，充分地 | |
参考例句： |
|
|
|
|
50
varied
|
|
| adj.多样的，多变化的 | |
参考例句： |
|
|
|
|
51
favourable
|
|
| adj.赞成的，称赞的，有利的，良好的，顺利的 | |
参考例句： |
|
|
|
|
52
illustrates
|
|
| 给…加插图( illustrate的第三人称单数 )； 说明； 表明； （用示例、图画等）说明 | |
参考例句： |
|
|
|
|
53
antecedence
|
|
| n.居先，优先 | |
参考例句： |
|
|
|
|
54
unconditional
|
|
| adj.无条件的，无限制的，绝对的 | |
参考例句： |
|
|
|
|
55
zoology
|
|
| n.动物学，生态 | |
参考例句： |
|
|
|
|
56
scanty
|
|
| adj.缺乏的，仅有的，节省的，狭小的，不够的 | |
参考例句： |
|
|
|
|
57
premature
|
|
| adj.比预期时间早的；不成熟的，仓促的 | |
参考例句： |
|
|
|
|
58
superfluous
|
|
| adj.过多的，过剩的，多余的 | |
参考例句： |
|
|
|
| 欢迎访问英文小说网 |