A word about the works mentioned in the text: They are not cited here, nor are the primary writings of the authors, which can be found easily under the author's name in the library. A note at the beginning of the book explains the use of translated titles in the text itself.
In this bibliographical essay we make no attempt to be exhaustive, but we hope that it will serve as a useful guide to further reading. Only English-language books are cited here, and--with rare exceptions when there are no other convenient sources--articles and theses have been omitted. The reader should also keep in mind that for intellectuals of more recent periods audiovisual sources are also available, although they are not cited here. These as well as printed sources may be found by using the electronic tools at the disposal of modern researchers and readers. Finally, it is worth noting that the English-language literature on some of the authors discussed in this book presents surprising gaps. Also, lest we become too dependent on electronic research facilities, readers would be well served by taking advantage of bibliographies and footnote citations in the works mentioned here. Biographies are listed only when they may be particularly useful for an analysis of the political thought of the person under consideration.
Aside from works that discuss political theory in the abstract, there are no recent books comparable to the present text. The closest general work is George H. Sabine , A History of Political Theory, 3rd edition ( New York, 1961), the scope of which begins in ancient times and reaches fascism and socialism. Another book, even older but still useful for the context of European political thought, is a collection of essays, J. P. Mayer, et al., Political Thought: The European Tradition ( London, 1942). A full development of the themes treated in our Introduction is Salvo Mastellone, A History of Democracy in Europe: From Montesquieu to 1989 ( Florence, 1995). On the twentieth century, there are Karl Dietrich Bracher's The Age of Ideology ( London, 1984) and Norberto Bobbio, Ideological Profile of the Twentieth Century ( Princeton, 1995).