This section of the book is from the "Introduction To Public Finance" book, by Carl Copping Plehn.
Since the emergence of the monarchical State from feudalism the trend of affairs has been directed by the growth of constitutionalism, — or the representation of the people in the government. As the whole advance of this movement turned upon the success of the people in obtaining the control of the purse, it is evident that the resulting changes in the financial system must have been very important. The long history through which the different revenues have passed, the necessity of constant compromise between the
different interested parties, and the various changes made necessary by the growth in the economic life of the world, all these have left modern States with a most confused jumble of revenues. Yet with all the irregularities and anomalies that can be found in the revenues of any modern State, there is still in every case a more or less clearly traceable systematic development. This growth of system is clearly due to the work of the representatives, in whose hands the development of constitutional government finally placed the control of the collection and spending of the public money. As these representatives realised the need of revenues, they naturally sought for some principles of right and justice to guide them in the choice of sources. The result has been a partial uniformity in the systems of the different countries.
It should not, however, be imagined that this uniformity is very great, nor that the systems of the different countries are alike in details. But somewhat the same fundamental ideas seem to underlie all. There are also great differences. Thus one country chooses to obtain the larger part of its revenues from a tax not used at all in another. Historical practices and differences in the frame of government necessitate modifications even of the same principle.That bugbear of the student of Public Finance, practical expediency, which has ruined many a fine theory, works in the most astonishing ways to prevent the execution of approved principles.