CHAPTER I.

INTRODUCTION.

One of the most frequent sources of mistaken views in economical science, arises from confounding the nature of _universal_ with that of _general principles_.

§ _Universal principles_, such as the fact that every number ending with the figure five is itself divisible by five, rarely occur except in the exact sciences. Universal principles are those which do not admit of a single exception.

_General principles_ are those which are much more frequently obeyed than violated. Thus it is generally true that _men will be governed by what they believe to be their interest_. Yet it is certainly true that many individuals will at times be governed by their passions, others by their caprice, others by entirely benevolent motives: but all these classes together, form so small a portion of mankind, that it would be unsafe in any inquiry to neglect the great principle of self-interest. Notwithstanding, however, all the exceptions we may meet with, it is impossible to take any just views of society without the admission of general principles, and on such grounds they will be used in these pages.

Self-interest, combined in various degrees with knowledge, assumes the most diversified forms. It excites our contempt or raises our admiration, according to the littleness or the greatness of the object it pursues—according to the temporary or the more distant advantages it seeks. On the one hand, it governs the minister of a party on his doubtful eminence, whilst on the other it guides the enlightened statesman to the object of his distant ambition.

§ Again, it is admitted as a general principle that _each man is the best judge of his own wants and of his own interest_. Now although many individuals, and even whole classes of society, have at times been thought by more enlightened men to have formed erroneous opinions as to their true interest, yet, when it is remembered, that every man must see many views of his own case, and must know many facts connected with it, which he has not communicated even to his most confidential adviser, those who have had most experience are most inclined to believe that the exceptions are much less frequent than at first sight would appear.

Another source of erroneous opinions arises from neglecting causes apparently insignificant.

In taking a comprehensive view of any subject, it is very desirable to throw into the shade all its minor points; but in estimating the consequences of any set of facts, there is another condition which must be fulfilled, before we can arrive at accurate conclusions. If we are about to neglect a cause on account of its apparent insignificance, it is _essential_ that it should not be one of _frequent_ recurrence. Thus, if a labourer inconsiderately lift his shovel but an inch or two more than is necessary to throw its load into his barrow, although the exertion of force is trivial in each instance, its repeated occurrence during the whole day, will produce at its conclusion a very sensible difference either in fatigue or in the amount of the work done. Napoleon is said to have remarked of Laplace, when he was Minister of the Interior, that he was too much occupied with considering _les infiniment petites_. To dwell upon small affairs which are isolated, is not the province of a statesman; but to integrate the effect of their constant recurrence is worthy of the greatest.

One of the most important processes in all inquiry, is to divide the subject to be considered into as many different questions as it will admit of, and then to examine each separately, or in other words to suppose that each single cause successively varies whilst all the others remain constant.

But this most obvious doctrine of common sense has frequently been contested in questions of economical science, and has been often characterized as theoretical, and as entirely inapplicable to the affairs of life. It is certain that very little progress can be made in any subject without this aid, and it is hopeless for those whose minds are incapable of mastering the simpler questions, ever to institute successfully an investigation into their united action.

A familiar illustration will explain this better. Two men are making an excavation, removing the earth in the usual way with spades and wheelbarrows.

One of these men, Q., does more work than his companion P., and if an inquiry is made, Why is this so? the usual reply would be that Q. is either stronger, more active, or more skilful than P.

Now it is the third of these qualifications which is the most important, because if Q. were inferior even both in strength and in activity, he might yet by means of his skill perform a greater quantity of work without fatigue.

He might have ascertained that a _given_ weight of earth raised at each shovelfull, together with a certain number of shovelfulls per hour, would be more advantageous for his strength than any other such combination.

That a shovel of a certain weight, size, and form would fatigue him less than those of a different construction.

That if its handle were two or three inches longer than he required, its additional weight would at the end of the day have been uselessly lifted many hundred times.

That if each spadefull of earth were lifted but an inch or two above the barrow beyond what was necessary, a still greater waste of force would arise.

That if the barrow itself had its wheel at a distance beyond the centre of its load, it would be more fatiguing to draw.

That if the barrow had upright sides, it would require more exertion to turn out its load than if its sides were much inclined.

Thus although Q. might have less strength and less activity than P., he might yet by skill and practice, have arrived at some combination of these tools which should enable him with less fatigue to do more daily work than P.

But in order to have arrived at this degree of skill, Q. must when a boy have been taught to examine _separately_ the consequences of any defect or inconvenience in the parts of the tools he was to use in after life, or in the modes of using them. If not so taught, he must have arrived at the same knowledge by the slower and more painful effort of his own reflections.

In either case he would be able to communicate his knowledge to his friends or his children; and if circumstances induced or obliged him to enter upon a new trade, he would naturally apply those principles to his new tools. Indeed, whatever subject might be presented to a mind thus trained, such habits of inquiry would most probably be applied to its examination. Thus, by the early education of his reasoning faculties on the trade by which he is to subsist, he would not only render his own labour more productive, but would have his mind better prepared for the reception of other truths.