"The Secret Doctrine is one of the most remarkable books in the world. I realize how far beyond my feeble powers is the task of conveying an adequate idea of the teachings contained within its covers. It has a history, however, a history of peculiar interest to the student who from its rich store seeks to garner the wisdom which, as the apostle has said, is like meat fit only for the strong. How it came to be written, and under what circumstances it was written, and under what circumstances it was written, is the topic of this book."
January 1, 1970
https://en.wikiquote.org/wiki/The_Secret_Doctrine