But the subject is too vast for a single treatise, or indeed for a single mind. This will be evident if we consider the extent of one of its subordinate branches, the limits to be assigned to posthumous power. On the death of a proprietor, ought his property to revert to the state, as it does in Turkey, or to go to his children, as it does in France, or to be subject to his disposition by deed or by will? If it be subjected to his disposition, ought he to have merely the power of appointing his immediate successors, or of entailing it for one generation, or for two, or for ever? Is it advisable that he should have the power, not only of appointing a successor to his property, but of directing how that successor shall employ it? And ought such a power to be unlimited, or to be confined to certain purposes, or within a certain period? Ought the laws of succession and of testamentary power to be the same as respects land and movables, or to differ totally, or in any, or what, particulars? Ought these questions to be resolved differently in an old country and in a colony, in a monarchy, in an aristocracy, and in a republic? If Political Economy be a branch of the art of government, these inquiries form a branch, though a very small one, of Political Economy. But there is scarcely any one of them which it would not require a long treatise to answer satisfactorily. How many, for instance, are the considerations which must be attended to in a discussion as to the propriety of enabling individuals to found permanent institutions for the purposes of religion, of education, and of charity, and as to the period for which they ought to be allowed to govern them from the grave? It is almost impossible to overrate the importance of the art of government. With the exception, perhaps, of morality, it is the most useful of the mental arts; but, with no exception whatever, it is the most extensive. Too much attention cannot be given to it; but that attention should be subdivided. Too many minds cannot be employed on it, but each should select a single province; and the narrower the province, of course the more completely is it likely to be mastered. My second definition, that which defines Political Economy as the art which teaches what are the institutions and habits most favourable to the production and accumulation of wealth, is not liable to similar objections. It opens a field of inquiry, positively indeed wide, but comparatively narrow. The object proposed by the political economist is no longer human happiness, but the attainment of one of the means of human happiness, wealth.