Archbishop Whately has well remarked, that the demonstrations of Euclid would not have commanded universal assent, if they had been applicable to the pursuits and fortunes of individuals; and of all branches of human knowledge, Political Economy, from the complexity of its relations, and the vagueness of its nomenclature, offers the easiest scope to a prejudiced or an uncandid reasoner. The great improvements that are taking place in our commercial and financial policy, will tend to diminish this obstacle to political science by removing the subjects of contest. And we may hope that its force will be still further diminished by the mere progress of the study, as its terms become better defined, and more and more of its principles are established and recognised. But it would be vain to hope that it ever will be got rid of, or that men will examine questions which come home to their business and bosoms, with the unbiassed spirit which urges the astronomer or the mathematician. Another cause which has rendered fruitless much of the attention bestowed on Political Economy, has been the frequent attempt to discuss insulated questions connected with it, by those who have not previously endeavoured to acquaint themselves with its general outline. In some sciences this is, to a certain extent, practicable. In those sciences which consist in a great measure of independent facts, such as law, or natural history, a single branch may sometimes be studied successfully. But in Political Economy the different propositions are so mutually dependent, that it is impossible to reason safely concerning any one without constantly bearing in mind all the others. And yet nothing is more common than to find persons writing books and making speeches, and even proposing, with the utmost confidence, legislative measures involving principles as to which the acutest and most diligent inquirer has not been able to make up his mind, not only without having settled within themselves the meaning of their principal terms, but even without being themselves aware that they are using words to which they attach no definite ideas.