 Essays on Some Unsettled Questions of Political Economy. Essays on Some Unsettled Questions of Political Economy by John Stuart Mill. Essay 5. On the definition of political economy and on the method of investigation proper to it. Part 3. Having now shown that the method a priori in political economy and in all other branches of moral science is the only certain or scientific method of investigation that the a posteriori method or that of specific experience as a means of arriving at truth is inapplicable to these subjects we shall now be able to show that the latter method is not withstanding of great value in the moral sciences, namely not as a means of discovering truth but of verifying it and reducing to the lowest point that uncertainty before alluded to as arising from the complexity of every particular case, and from the difficulty not to say impossibility of being assured a priori that we have taken into account all the material circumstances. If we could be quite certain that we knew all the facts of the particular case we could derive little additional advantage from specific experience. The causes being given we may know what will be their effect without the actual trial of every possible combination since the causes are human feelings and outward circumstances fitted to excite them and as these for the most part are or at least might be familiar to us we can more surely judge of their combined effects from that familiarity than from any evidence which can be elicited from the complicated and entangled circumstances of an actual experiment. If the knowledge what are the particular causes operating in any given instance were revealed to us by infallible authority then if our abstract science were perfect we should become prophets but the causes are not so revealed that they are to be collected by observation and observation in circumstances of complexity is apt to be imperfect. Some of the causes may lie beyond observation many are apt to escape it unless we are on the outlook for them and it is only the habit of long and accurate observation which can give us so correct a preconception what causes are likely to find as shall induce us to look for them in the right quarter. But such is the nature of the human understanding that the very fact of attending with intensity to one part of a thing has a tendency to withdraw the attention from the other parts. We are consequently in great danger of averting a portion only of the causes which are actually at work and if we are in this predicament the more accurate our deductions and the more certain our conclusions in the abstract that is making abstraction of all circumstances except those which form part of the hypothesis the less we are likely to suspect that we are in error for no one can have looked closely into the sources of felicitous thinking without being deeply conscious that the coherence and neat concatenation of our philosophical systems is more apt than we are commonly aware to pass with us as evidence of their truth. We cannot therefore too carefully endeavor to verify our theory by comparing in the particular cases to which we have accessed the results which it would have led us to predict with the most trustworthy accounts we can obtain of those which have been actually realized. The discrepancy between our anticipations and the actual fact is often the only circumstance which would have drawn our attention to some important disturbing cause which we had overlooked. Nay, it often discloses to us errors in thought, still more serious than the omission of what can with any propriety be termed a disturbing cause. It often reveals to us that the basis itself of our whole argument is insufficient, that the data from which we had reasoned comprise only a part and not always the most important part of the circumstances by which the result is really determined. Such oversights are committed by very good reasoners, and even by a still rarer class that of good observers. It is a kind of error to which those are particularly liable, whose views are the largest and most philosophical, for exactly in that ratio are their minds more accustomed to dwell upon those laws, qualities, and tendencies which are common to large classes of cases and which belong to all places and all times, while it often happens that circumstances most peculiar to the particular case or era have a far greater share in governing that one case. Although therefore a philosopher may be convinced that no general truth can be attained in the affairs of nations by the a posteriori road, it does not the less behoove him according to the measure of his opportunities to shift and scrutinize the details of every specific experiment. Throughout this he may be an excellent professor of abstract science, for a person may be of great use who points out correctly that effects will follow from certain combinations of possible circumstances, in whatever tract of the extensive reason of hypothetical cases those combinations may be found. He stands in the same relation to the legislator as the mere geographer to the practical navigator, telling him the latitude and longitude of all sorts of places, but not how to find whereabouts he himself is sailing. If however he does no more than this he must rest contented to take no share in practical politics, to have no opinion, or to hold it with extreme modesty on the applications which should be made of his doctrines to existing circumstances. No one who attempts to lay down propositions from the guidance of mankind, however perfect his scientific accrutiments can dispense with the practical knowledge of the actual modes in which the affairs of the world are carried on, and an extensive personal experience of the actual ideas, feelings, and intellectual and moral tendencies of his own country and of his own age. The true practical statesman is he who combines this experience with a profound knowledge of abstract political philosophy. Their accrutiment, without the other, leaves him lame and impotent, if he is sensible of the deficiency, renders him obstrate and presumptuous if, as is more probable, he is entirely unconscious of it. Such then are the respective offices and uses of the a priori and the a posteriori methods, the method of abstract science and that of specific experiment, as well as in political economy, as in all other branches of social philosophy. Truth compels us to express our conviction that whether among those who have written on these subjects or among those for whose use they wrote, few can be pointed out who have allowed to each of these methods its just value, and systematically kept each to its proper objects and functions. One of the peculiarities of modern times, the separation of theory from practice, of the studies of the closet from the outward business of the world, has given a wrong bias to the ideas and feelings both of the student and of the man of business. Each undervalues that part of the materials of thought with which he is not familiar. The one despises all comprehensive views, the other neglects details. The one draws his notion of the universe from the few objects with which his course of life has happened to render him familiar. The other having got demonstration on his side, and forgetting that it is only a demonstration, nisi, a proof at all times liable to be set aside by the addition of a single new fact to the hypothesis, denies instead of examining and sifting the allegations which are opposed to him. For this he has considerable excuse in the worthiness of the testimony on which the facts brought forward to invalidate the conclusions of theory really rest. In these complex matters, men see with their preconceived opinions, not with their eyes, an interested or passionate man's statistics are of little worth, and a year seldom passes without examples of the astounding falsehoods which large bodies of respectable men will back each other in publishing to the world as facts within their personal knowledge. It is not because a thing is asserted to be true, but because in its nature it may be true, that a sincere and patient inquirer will feel himself called upon to investigate it. He will use the assertions of opponents not as evidence, but indications leading to evidence, suggestions of the most proper course for his own inquiries. But while the philosopher and the practical man bandy half-truths with each other, we may seek far without finding one who, placed on a higher eminence of thought, comprehends as a whole what they see only in separate parts. Who can make the anticipations of the philosopher guide the observation of the practical man, and the specific experience of the practical man warn the philosopher where something is to be added to his theory. The most memorable example in modern times of a man who united the spirit of philosophy with the pursuits of active life, and kept wholly clear of the particularities and prejudices both of the student and the practical statesman, was Turgot. The wonder not only of his age, but of history, for his astonishing combination of the most opposite and, judging from common experience, almost incompatible, excellences. Though it is impossible to furnish any test by which a speculative thinker, either in political economy or in any other branch of social philosophy, may know that he is competent to judge of the applications of his principles to the existing condition of his own or any other country, indications may be suggested by the absence of which he may well and surely know that he is not competent. His knowledge must at least enable him to explain and account for what is, or he is an insufficient judge of what ought to be. If a political economist, for instance, finds himself puzzled by any recent present commercial phenomena, if there is any mystery to him in the late or present state of the productive industry of the country, which his knowledge of principle does not enable him to unriddle, he may be sure that something is wanting to render his system of opinions a safe guide in existing circumstances, either some of the facts which influence the situation of the country and the course of events are not known to him or, knowing them, he knows not what ought to be their effects. In the latter case, his system is imperfect, even as in an abstract system. It does not enable him to trace correctly all the consequences even of assumed premises, though he succeeded in throwing doubts upon the reality of some of the phenomena which he is required to explain, his task is not yet completed. Even then he is called upon to show how the belief which he deems unfounded arose, and what is the real nature of the appearances which gave a color of probity to allegations which examination proves to be untrue. When the speculative politician has gone through this labor, has gone through it conscientiously, not with the desire of finding his system complete, but of making it so, he may deem himself qualified to apply his principles to the guidance of practice, but he must still continue to exercise the same discipline upon every new combination of facts as it arises. He must make a large allowance for the disturbing influence of unforeseen causes, and must carefully watch the result of every experiment in order that any residium of facts which his principles did not lead him to accept and do not enable him to explain may become the subject of a fresh analysis, and furnish the occasion for a consequent enlargement or correction of his general views. The method of the practical philosopher consists therefore of two processes, the one analytical, the other synthetical. He must analyze the existing state of society to its elements, not dropping and losing any of them by the way, after referring to the experience of individual man to learn the law of each of these elements, that is, to learn what are its natural effects and how much of the effect follows from so much of the cause when not contracted by any other cause, there remains an operation of synthesis to put all these effects together and from what they are separately to collect what would be the effect of all the causes acting at once. If these various operations could be correctly performed, the result would be prophecy, but as they can be performed only with a certain approximation to correctness, mankind can never predict with absolute certainty, but only with a lesser greater degree of probability, according as they are better or worse apprised what the causes are, have learnt with more or less accuracy from experience the law to which each of those causes when acting separately conforms, and have summed up the aggregate effect more or less carefully. With all the precautions which have been indicated, there will still be some danger of falling into partial views, but we shall at least have taken the best securities against them. All that we can do more is to endeavor to be impartial critics of our own theories and to free ourselves as far as we are able from that reluctance from which few inquirers are altogether him to expect, and do not enable him to explain, may become the subject of a fresh analysis, and furnish the occasion for a consequent enlargement or correction of his general views. If indeed every phenomenon was generally the effect of no more than one cause, the knowledge of the law of that cause would, unless there was a logical error in our reasoning, enable us confidently to predict all the circumstances of the phenomenon. We might then, if we had carefully examined our premises and our reasoning, and found no flaw, venture to disbelieve the testimony which one might be brought to show that matters had turned out differently from what we should have expected. If the causes of erroneous conclusions were always patent on the face of the reasonings which led to them, the human understanding would be a far more trustworthy instrument than it is. But the narrowest examination of the process itself will help us little towards discovering that we have omitted part of the premise which we ought to have taken into our reasoning. Effects are commonly determined by a concurrence of causes. If we have overlooked any one cause, we may reason justly from all the others, and only be the further wrong. Our premise will be true, and our reasoning correct, and yet the result of no value in the particular case. There is therefore almost always room for a modest doubt as to our practical conclusions. Against false premises and unsound reasoning, a good mental discipline may effectually secure us, but against the danger of overlooking something, neither strength of understanding nor intellectual cultivation can be more than a very imperfect perfection. A person may be warranted in feeling confident that whatever he has carefully contemplated with his mind's eye he has seen correctly, but no one can be sure that there is not something in existence which he has not seen at all. He can do no more than satisfy himself that he has seen all that is visible to any other persons who have concerned themselves with the subject. For this purpose he must endeavor to place himself at their point of view, and strive earnestly to see the object as they see it, nor give up the attempt until he has either added the appearance which is floating before them to his own flock of realities, or made out clearly that it is an optical deception. The principles of which we have now stated are by no means alien to common apprehension. They are not absolutely hidden from anyone, but are commonly seen through a mist. We might have presented the latter part of them in a phraseology in which they would have seemed the most familiar of truisms. We might have cautioned inquirers against too extensive generalization, and reminded them that there are exceptions to all rules, such as the current language of those who distrust comprehensive thinking without having any clear notion why or where it ought to be distrusted. We have avoided the use of these expressions purposely because we deem them superficial and inaccurate. The error, when there is error, does not arise from generalizing too extensively—that is, from including too wide a range of particular cases in a single proposition. Doubtless a man often asserts of an entire class what is only true of a part of it. But his error generally consists not in making too wide an assertion, but in making the wrong kind of assertion. He predicted an actual result, when he should have predicted a tendency to that result—a power acting with a certain intensity in that direction. With regard to exceptions, in any tolerably advanced science, there is always some other and distinct principle cutting into the former some other force which impinges against the first force and deflects it from its direction. There are not a law and an exception to that law—the law acting in ninety-nine cases and the exception in one. There are two laws, each possibly acting in the whole hundred cases and bringing about a common effect by their conjunct operation. If the force, which being the less conspicuous of the two, is called the disturbing force, prevails sufficiently over the other force in some one case. To constitute that case what is commonly called an exception, the same disturbing force acts as a modifying cause in many other cases which no one will call exceptions. Thus if it were stated to be a law of nature that all heavy bodies fall to the ground, it would probably be said that the resistance of the atmosphere which prevents a balloon from falling constitutes the balloon an exception to the pretended law of nature. But the real law is, after all, heavy bodies tend to fall, and to this there is no exception, not even the sun and moon, for even they, as every astronomer knows, tend towards the earth with a force exactly equal to that with which the earth tends toward them. The resistance of the atmosphere might, in the particular case of the balloon, from a misapprehension of what the law of gravitation is, be said to prevail over the law, but its disturbing effect is quite as real in every other case, since though it does not prevent it retards the fall of all bodies whatever. The rule and the so-called exception do not divide the cases between them. Each of them is a comprehensive rule extending to all cases. To call one of these concurrent principles an exception to the other is superficial and contrary to the correct principles of nomenclature and arrangement. An effect of precisely the same kind and arising from the same cause ought not to be placed in two different categories merely as there does or does not exist another cause prepondering over it. It is only in art, as distinguished from science, that we can with propriety speak of exceptions. Art, the immediate end of which is practice, has nothing to do with causes except as the means of bringing about effects. However heterogeneous the causes, it carries the effects of them all into one single reckoning, and according as the sum total is plus or minus, according as it falls above or below a certain line. Art says do this, or abstain from doing it. The exception does not run by insensible degrees into the rule, like what are called exceptions in science. In a question of practice it frequently happens that a certain thing is either fit to be done, or fit to be altogether abstained from, being no medium. If in the majority of cases it is fit to be done, that is made the rule. When a case subsequently occurs in which the thing ought not to be done, an entirely new leaf is turned over, and the rule is now done with, and dismissed. A new train of ideas is introduced, between which and those involved in the rule there is a broad line of demarcation, as broad and transient as the difference between I and no. Very possibly between the last case, which comes within the rule, and the first of the exception, there is only the difference of a shade, but that shade probably makes the whole interval between acting in one way and in a totally different one. We therefore, in talking of art, unobjectionably speak of the rule and the exception, meaning by the rule the cases in which there exists a preponderance, however slight, of inducement for acting in a particular way, and by the exception the cases in which the preponderance is on the contrary side. The End of Part 3 of SA 5. End of SA 5. End of Essays on Some Unsettled Questions of Political Economy by John Stuart Mill.