Preface to 1970 Edition
Since 1937 no revision has been made to the text of Dr. Esslemont's book, although in 1950 some minor corrections were introduced. On the other hand, the diffusion and development of the Baha'i Faith since that time have been tremendous, and there has been added to Baha'i bibliography a rich legacy of incomparable expositions, translations and historical accounts from the pen of Shoghi Effendi, Guardian of the Faith and the appointed interpreter of its Sacred Writings (4:1)

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