The science known as Political Economy, which for a century has so much interested thinkers, is to-day more generally diffused than ever before. It shares with politics proper the attention of the great journals, which are to-day the most important means of spreading information; but the public is so tired of theories and systems that now the demand is for so-called "positive" matter, i.e. in political economy, custom-house abstracts, statistical documents, and government reports, such as will throw the light of experience on the important questions which are being agitated before the country, and which so greatly interest all classes of society.
I make no objection to this tendency; it is good, and in accord with the laws which govern the development of all branches of science. I will only observe that theory ought not to be confounded with systems, although in the infancy of all sciences the instinct of system necessarily attempts to outline theories. I will add that theory should always have some part, small though it may be, in the development of a science; and that, to a man of my profession in particular, more than to any other, it should be permissible to consider from an exclusively theoretical