Self-Suggestion and the New Huna Theory of Mesmerism and Hypnosis is a practical manual of self-suggestion using the Huna techniques, including detailed instructions as to how the operation works. Huna (Hawaiian for "secret") is the word adopted by the author in 1936 to describe his theory of metaphysics. "This information concerning those parts of psychology which we have come to call hypnosis, mesmerism and suggestion, is being presented as an addition to the scant literature on the ancient psycho-religious system of the Polynesians called "Huna" or the "Secret"."
Pretty enjoyable and brief. There were some parts that were too speculative and had me rolling my eyes, but I think the models proposed about getting higher, middle and lower selves to communicate were both interesting and practical in many ways.
Ignoring the fact Long presents the "history" of the Huna as fact, the draw here is the application of his theories. They fit neatly in with similarly useful models proposed by the likes of Napoleon Hill.
The useful meat of the book is admittedly slim, but the book as a whole is too and it doesn't outstay its welcome. Certainly worth a read.