Here is a thoughtful review of The Secret Teachers of the Western World by Nicholas Collof, from his excellent website, Golgonooza, named after William Blake’s mythical city of art and the imagination. Like Blake, Nicholas “shall not cease from mental fight” and his followers are the better for it.
Gary Lachman 
Great review! The direct link to it is http://ncolloff.blogspot.com/2015/12/the-secret-teachers-of-western-world.html
Many thanks Keith, and yes I neglected to add the link. I’ve since added it; thanks again for drawing my attention to it and for liking the review.