I am not one of those who think that a science, as such, has natural and unalterable boundaries. In the domain of ideas, as in that of facts, all things are bound up and linked together; truths run into one another; and there is no science which, in order to be complete, might not be made to include all. It has been said with reason that to an infinite intelligence there is but a single verity. It is, then, our weakness which obliges us to study separately a [p071] certain order of phenomena, and the classifications which result from it cannot escape a certain decree of arbitrariness. The true merit is to explain accurately the facts, their causes, and their consequences. It is also a merit, although a much less and a purely relative one, to determine, not rigorously—for that is impossible—but rationally, the order of the facts which we propose to study. I say this in order that it may not be supposed that I intend to criticise my predecessors if I give to Political Economy limits somewhat different from those which they have assigned to that science. Economists have of late been reproached with addicting themselves too much to the study of ‹Wealth›. It has been wished that they had found a place in their science for all that, directly or indirectly, contributes to the happiness or sufferings of humanity. They have even been supposed to deny everything which they did not profess to teach—for example, the phenomena of sympathy, which is as natural to the heart of man as the principle of self-interest. It is as if they accused the mineralogist of denying the existence of the animal kingdom. What! Wealth, the laws of its production, of its distribution, of its consumption,—is not this a subject vast enough, and important enough, to be made the object of a special science? If the conclusions of the Economist were at variance with those of morals and politics. I could conceive ground for the accusation. One might say to him, “In limiting your science you are mistaken, for it is not possible for two verities to run counter to each other.” Perhaps one result of the work which I now submit to the public may be, that the Science of Wealth will be found to be in perfect harmony with all the other sciences. Of the three terms comprehended in the human destinies—Sensation, Effort, Satisfaction—the first and the last are always and necessarily confounded in the same individuality. It is impossible to imagine them separated. We can conceive a sensation unsatisfied, a want unappeased, but it is quite impossible to suppose the ‹want› to be in one man and the ‹satisfaction› to be in another. If the same observation applied to the middle term, ‹Effort›, man would be a being completely solitary. The Economic phenomena would then manifest themselves in an isolated individual. There might be a juxtaposition of persons, but there could be no society; there might be a Personal, but not a Political, Economy.