George Catlin 
History of the Political Philosophers [PDF ebook] 

Originally published in 1939, this book was intended as a guide to political theory intelligible to the common reader, with quotations from the original sources sufficiently extensive to enable them to sample for themselves the ‘taste’ and ‘colour’ of these writings. This history of theory has been placed against brief descriptions, as background, of the civilization of the times, as the reader passes down the avenues of thought from age to age. It is a history of political thought set against the background of the history of civilization, but that thought is also displayed in the setting of the characteristics and biographies of the thinkers, whose minds we search and whom we seek to know familiarly, however long ago gone to dust.