Political Economy, therefore, presupposes all the physical sciences; it takes for granted all such of the truths of those sciences as are concerned in the production of the objects demanded by the wants of mankind; or at least it takes for granted that the physical part of the process takes place somehow. It then inquires what are the phenomena of mind which are concerned in the production and distribution [[8]] of those same objects; it borrows from the pure science of mind the laws of those phenomena, and inquires what effects follow from these mental laws, acting in concurrence with those physical one. [[9]]
From the above considerations the following seems to come out as the correct and complete definition of Political Economy:—"The science which treats of the production and distribution of wealth, so far as they depend upon the laws of human nature." Or thus—science relating to the moral or psychological laws of the production and distribution of wealth."
For popular use this definition is amply sufficient, but it still falls short of the complete accuracy required for the purposes of the philosopher. Political Economy does not treat of the production and distribution of wealth in all states of mankind, but only in what is termed the social state; nor so far as they depend upon the laws of human nature, but only so far as they depend upon a certain portion of those laws. This, at least, is the view which must be taken of Political Economy, if we mean it to find any place in an encyclopedical division of the field of science. On any other view, it either is not science at all, or it is several sciences. This will appear clearly, if, on the one hand, we take a general survey of the moral sciences, with a view to assign the exact place of Political Economy among them; while, on the other, we consider attentively the nature of the methods or processes by which the truths which are the object of those sciences are arrived at.
Man, who, considered as a being having a moral or mental nature, is the subject-matter of all the moral sciences, may, with reference to that part of his nature, form the subject of philosophical inquiry under several distinct hypotheses. We may inquire what belongs to man considered individually, and as if no human being existed besides himself; we may next consider him as coming into contact with other individuals; and finally, as living in a state of society, that is, forming part of a body or aggregation of human beings, systematically co-operating for common purposes. Of this last state, political government, or subjection to a common superior, is an ordinary ingredient, but forms no necessary part of the conception, and, with respect to our present purpose, needs not be further adverted to.
Those laws or properties of human nature which appertain to man as a mere individual, and do not presuppose, as a necessary condition, the existence of other individuals (except, perhaps, as mere instruments or means), form a part of the subject of pure mental philosophy. They comprise all the laws of the mere intellect, and those of the purely self-regarding desires.
Those laws of human nature which relate to the feelings called forth in a human being by other individual human or intelligent beings, as such; namely, the affections, the conscience, or feeling of duty, and the love of approbation; and to the conduct of man, so far as it depends upon, or has relation to, these parts of his nature—form the subject of another portion of pure mental philosophy, namely, that portion of it on which morals, or ethics, are founded. For morality itself is not a science, but an art; not truths, but rules. The truths on which the rules are founded are drawn (as is the case in all arts) from a variety of sciences; but the principal of them, and those which are most nearly peculiar to this particular art, belong to a branch of the science of mind.
Finally, there are certain principles of human nature which are peculiarly connected with the ideas and feelings generated in man by living in a state of society, that is, by forming part of a union or aggregation of human beings for a common purpose or purposes. Few, indeed, of the elementary laws of the human mind are peculiar to this state, almost all being called into action in the two other states. But those simple laws of human nature, operating in that wider field, give rise to results of a sufficiently universal character, and even (when compared with the still more complex phenomena of which they are the determining causes) sufficiently simple, to admit of being called, though in a somewhat looser sense, laws of society, or laws of human nature in the social state. These laws, or general truths, form the subject of a branch of science which may be aptly designated from the title of social economy; somewhat less happily by that of speculative politics, or the science of politics, as contradistinguished from the art. This science stands in the same relation to the social, as anatomy and physiology to the physical body. It shows by what principles of his nature man is induced to enter into a state of society; how this feature in his position acts upon his interests and feelings, and through them upon his conduct; how the association tends progressively to become closer, and the co-operation extends itself to more and more purposes; what those purposes are, and what the varieties of means most generally adopted for furthering them; what are the various relations which establish themselves among human beings as the ordinary consequence of the social union; what those which are different in different states of society; in what historical order those states tend to succeed one another; and what are the effects of each upon the conduct and character of man.
This branch of science, whether we prefer to call it social economy, speculative politics, or the natural history of society, presupposes the whole science of the nature of the individual mind; since all the laws of which the latter science takes cognizance are brought into play in a state of society, and the truths of the social science are but statements of the manner in which those simple laws take effect in complicated circumstances. Pure mental philosophy, therefore, is an essential part, or preliminary, of political philosophy. The science of social economy embraces every part of man's nature, in so far as influencing the conduct or condition of man in society; and therefore may it be termed speculative politics, as being the scientific foundation of practical politics, or the art of government, of which the art of legislation is a part [[10]].
It is to this important division of the field of science that one of the writers who have most correctly conceived and copiously illustrated its nature and limits,—we mean M. Say,—has chosen to give the name Political Economy. And, indeed, this large extension of the signification of that term is countenanced by its etymology. But the words "political economy" have long ceased to have so large a meaning. Every writer is entitled to use the words which are his tools in the manner which he judges most conducive to the general purposes of the exposition of truth; but he exercises this discretion under liability to criticism: and M. Say seems to have done in this instance, what should never be done without strong reasons; to have altered the meaning of a name which was appropriated to a particular purpose (and for which, therefore, a substitute must be provided), in order to transfer it to an object for which it was easy to find a more characteristic denomination.
What is now commonly understood by the term "Political Economy" is not the science of speculative politics, but a branch of that science. It does not treat of the whole of man's nature as modified by the social state, nor of the whole conduct of man in society. It is concerned with him 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 antagonizing 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 absolute ruler of all their actions. Under the influence of this desire, it shows mankind accumulating wealth, and employing that 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 portion 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. In this way a nearer approximation is obtained than would otherwise be practicable, to the real order of human affairs in those departments. This approximation is then to be corrected by making proper allowance for the effects of any impulses of a different description, which can be shown to interfere with the result in any particular case. Only in a few of the most striking cases (such as the important one of the principle of population) are these corrections interpolated into the expositions of Political Economy itself; the strictness of purely scientific arrangement being thereby somewhat departed from, for the sake of practical utility. So far as it is known, or may be presumed, that the conduct of mankind in the pursuit of wealth is under the collateral influence of any other of the properties of our nature than the desire of obtaining the greatest quantity of wealth with the least labour and self-denial, the conclusions of Political Economy will so far fail of being applicable to the explanation or prediction of real events, until they are modified by a correct allowance for the degree of influence exercised by the other cause.