In course of time the friends and comrades of Jean Jaurès will publish his biography and a new edition of his works; some of these were written with a certain amount of haste, and need careful revision. As, however, the complete biography has not yet been accomplished, I have had to seek other sources of information.

I am much indebted to M. Charles Rappoport's detailed and sympathetic analysis of Jaurès' ideas, contained in his book: Jean Jaurès; L’Homme, Le Penseur, Le Socialiste. M. Rappoport claims that his book is "Jaures explained by himself." A great part of it is, in fact, in Jaurès' own words, and the rest is a penetrating exposition of his mind.

From M. Levy-Bruhl's charming brochure, Quelques pages sur Jean Jaurès, I have gathered most of the details of Jaurès' youth contained in Chapter I. My other sources have been his own ​works: Etudes Socialistes (of which I have used for quotation the English translation by Mrs. Minturn), Les Preuves, L’Armée Nouvelle and numerous pamphlets containing his speeches.

Of some of the subjects on which Jaurès thought and spoke and wrote, such as Education and the French Revolution, no mention has been made in this book. His was a most varied, eager and all-embracing mind, and this short study naturally makes no pretension to be exhaustive. Its object is merely to give English readers some acquaintance with that force, at once harmonising and progressive, that was in Jaurès, and so to help to preserve his influence from being lost.