not as a political economist, but as a statesman or a moralist; and I shall expect from those who do me the honour of listening to them, not the full conviction which follows scientific reasoning, but the qualified assent which is given to the precepts of an art. In the next Lecture I shall consider whether the science of Political Economy may be more conveniently based on positive or on hypothetical principles. 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.,