There was another, earlier, book called The Secret of the West. I discovered its existence incidentally, on December 2000, while checking for this chain of words on google.com in view of a future english translation of my book. This eponym was published by Russian author Dimitri Merezhkovsky in 1930 (translated 1931). Its complete English title reads:
At first I didn't take note, dismissing this book from its title as one more of these tiresome "cosmic- consciousness" works brimming with extraterrestrials, telepathy, astrology and Mayas by some befuddled occultist...