The invitation was gladly accepted, and I had the great privilege of spending two and a half months as the guest of 'Abdu'l-Baha during the winter of 1919-1920.

During this visit 'Abdu'l-Baha discussed the book with me on various occasions.

He gave several valuable suggestions for its improvement and proposed that, when I had revised the manuscript, He would have the whole of it translated into Persian so that He could read it through and amend or correct it where necessary.

The revisal and translation were carried out as suggested, and 'Abdu'l-Baha found time, amid His busy life, to correct some three and a half chapters (Chapters I, II, V and part of III) before He passed away.
It is a matter of profound regret to me that 'Abdu'l-Baha was not able to complete the correction of the manuscript, as the value of the book would thereby have been greatly enhanced.

The whole of the manuscript has been carefully revised, however, by a committee of the National Baha'i Assembly of England, and its publication approved by that Assembly.
I am greatly indebted to Miss E.J.Rosenberg, Mrs.Claudia S.Coles, Mirza Lutfu'llah S.Hakim, Messrs.