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 Bahá’í Faith since that time have been tremendous,
and there has been added to Bahá’í 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.