Four Introductory Lectures on Political Economy

by Nassau William Senior

[LECTURE IV.]
THAT POLITICAL ECONOMY IS A POSITIVE, NOT AN HYPOTHETICAL SCIENCE.—DEFINITION OF WEALTH.

In the present Lecture I shall consider whether the science of Political Economy may be more conveniently based on positive or on hypothetical principles, and shall afterwards explain, more fully than I have as yet done, the sense in which I use the word wealth. Mr. John Mill, who has contributed much to Political Economy, as he has, indeed, to every science which he has touched, maintains that it is based on hypothesis. As it is impossible to change Mr. Mill’s language for the better, I shall extract the material parts of the passage in which he states and supports this opinion.

“Political Economy,”[D] he says, “is concerned with man solely as a being who desires to possess wealth, and who is capable of judging of the comparative efficacy of means for obtaining that end. It predicts only such of the phenomena of the social state as take place in consequence of the pursuit of wealth. It makes entire abstraction of every other human passion or motive, except those which may be regarded as perpetually antagonising principles to the desire of wealth; namely, aversion to labour, and desire of the present enjoyment of costly indulgences. These it takes, to a certain extent, into its calculations, because these do not merely, like other desires, occasionally conflict with the pursuit of wealth, but accompany it always as a drag or impediment, and are therefore inseparably mixed up in the consideration of it. Political Economy considers mankind as occupied solely in acquiring and consuming wealth, and aims at showing what is the course of action into which mankind, living in a state of society, would be impelled, if that motive, except in the degree in which it is checked by the two perpetual counter-motives above adverted to, were absolutely ruler of all their actions. Under the influence of this desire, it shows mankind accumulating wealth, and employing wealth in the production of other wealth; sanctioning by mutual agreement the institution of property; establishing laws to prevent individuals from encroaching upon the property of others by force or fraud; adopting various contrivances for increasing the productiveness of their labour; settling the division of the produce by agreement, under the influence of competition (competition itself being governed by certain laws, which laws are therefore the ultimate regulators of the division of the produce), and employing certain expedients, as money, credit, &c., to facilitate the distribution. All these operations, though many of them are really the result of a plurality of motives, are considered by Political Economy as flowing solely from the desire of wealth. The science then proceeds to investigate the laws which govern these several operations, under the supposition that man is a being who is determined, by the necessity of his nature, to prefer a greater proportion of wealth to a smaller in all cases, without any other exception than that constituted by the two counter-motives already specified. Not that any political economist was ever so absurd as to suppose that mankind are really thus constituted, but because this is the mode in which science must necessarily proceed. When an effect depends upon a concurrence of causes, those causes must be studied one at a time, and their laws separately investigated, if we wish, through the causes, to obtain the power of either predicting or controlling the effect; since the law of the effect is compounded of the laws of all the causes which determine it. The law of the centripetal and that of the tangential force must have been known, before the motions of the earth and planets could be explained, or many of them predicted. The same is the case with the conduct of man in society. In order to judge how he will act under the variety of desires and aversions which are concurrently operating upon him, we must know how he would act under the exclusive influence of each one in particular. There is, perhaps, no action of a man’s life in which he is neither under the immediate nor under the remote influence of any impulse but the mere desire of wealth. With respect to those parts of human conduct of which wealth is not even the principal object, to these Political Economy does not pretend that its conclusions are applicable. But there are also certain departments of human affairs, in which the acquisition of wealth is the main and acknowledged end. It is only of these that Political Economy takes notice. The manner in which it necessarily proceeds is that of treating the main and acknowledged end as if it were the sole end; which, of all hypotheses equally simple, is the nearest to the truth. The political economist inquires, what are the actions which would be produced by this desire, if, within the departments in question, it were unimpeded by any other?

[D] Essays on some Unsettled Questions of Political Economy, pp. 137, 138, 139, 140, 144, 145.

“It reasons, and, as we contend, must necessarily reason, from assumptions, not from facts. It is built upon hypotheses strictly analogous to those which, under the name of definitions, are the foundation of the other abstract sciences. Geometry presupposes an arbitrary definition of a line, ‘that which has length but not breadth.’ Just in the same manner does Political Economy presuppose an arbitrary definition of man, as a being who invariably does that by which he may obtain the greatest amount of necessaries, conveniences, and luxuries, with the smallest quantity of labour and physical self-denial with which they can be obtained in the existing state of knowledge. It is true that this definition of man is not formally prefixed to any work on Political Economy, as the definition of a line is prefixed to Euclid’s Elements; and in proportion as, by being so prefixed, it would be less in danger of being forgotten, we may see ground for regret that it is not done. It is proper that what is assumed in every particular case, should once for all be brought before the mind in its full extent, by being somewhere formally stated as a general maxim. Now, no one who is conversant with systematic treatises on Political Economy will question, that whenever a political economist has shown that, by acting in a particular manner, a labourer may obviously obtain higher wages, a capitalist larger profits, or a landlord higher rent, he concludes, as a matter of course, that they will certainly act in that manner. Political Economy, therefore, reasons from assumed premises—from premises which might be totally without foundation in fact, and which are not pretended to be universally in accordance with it. The conclusions of Political Economy, consequently, like those of geometry, are only true, as the common phrase is, in the abstract; that is, they are only true under certain suppositions, in which none but general causes—causes common to the whole class of cases under consideration—are taken into account.”

I have extracted this long passage because it is a clear statement of an original view of the science of Political Economy,—a view so plausible, indeed so philosophical, that I feel bound either to adopt it, or to state fully my reasons for rejecting it. I am not aware of any writer, except, perhaps, Mr. Merivale, who has expressed a formal concurrence in Mr. Mill’s doctrine; but Mr. Ricardo has practically assented to it.

His treatment of the science, indeed, is still more abstract than that proposed by Mr. Mill. He adds to Mr. Mill’s hypothesis other assumptions equally arbitrary; and he draws all his illustrations, not from real life, but from hypothetical cases. Out of these materials he has framed a theory, as to the distribution of wealth, possessing almost mathematical precision.

But neither the reasoning of Mr. Mill, nor the example of Mr. Ricardo, induce me to treat Political Economy as an hypothetical science. I do not think it necessary, and, if unnecessary, I do not think it desirable.

It appears to me, that if we substitute for Mr. Mill’s hypothesis, that wealth and costly enjoyment are the only objects of human desire, the statement that they are universal and constant objects of desire, that they are desired by all men and at all times, we shall have laid an equally firm foundation for our subsequent reasonings, and have put a truth in the place of an arbitrary assumption. We shall not, it is true, from the fact that by acting in a particular manner a labourer may obtain higher wages, a capitalist larger profits, or a landlord higher rent, be able to infer the further fact that they will certainly act in that manner, but we shall be able to infer that they will do so in the absence of disturbing causes. And if we are able, as will frequently be the case, to state the cases in which these causes may be expected to exist, and the force with which they are likely to operate, we shall have removed all objection to the positive as opposed to the hypothetical treatment of the science.