Moreover, it is to be remembered that this book is intended primarily for students, and that it may be useful to show them in what respects certain doctrines are open to criticism, either from the point of view of logic or of observation. We have attempted to confine such criticism within the strictest limits, partly because we did not wish the volume to become too bulky, and partly because we felt that what is important for our readers are not our own opinions, but the opinions of the masters of the science with which we deal. Wherever possible these have been given the opportunity of speaking for themselves, and for this reason we have not been afraid to multiply quotations. A special effort has been made to bring into prominence such doctrines—whether true or false—as have contributed to the formation of ideas generally accepted at the present time, or such as are connected with these in the line of direct descent. In other words, the book is an attempt to give an answer to the following questions: Who is responsible for formulating those principles that constitute the framework—whether provisionary or definitive it is not for us to determine—of economics as at present taught? At what period were these principles first enunciated, and what were the circumstances which accounted for their enunciation just at that period? Thus we have thought it not altogether out of place to pay some attention to those ideas which, although only on the borderland of economics, have exercised considerable influence either upon theory itself, upon legislation, or upon economic thought in general. We refer to such movements as Christian Socialism, Solidarism, and Anarchism. Had we considered it advisable to retain the official title by which this kind of work is generally known, we should have had to describe it as _A History of the Origin and Evolution of Contemporary Economic Doctrines_.