What a wonderful work from professor Alan Wallace, an authentic yogi, buddhist expert and scientist.
There are some books promising "practice of jhannas" or "jhanna achievement" but I only trust in this one coming from a true realized practitioner and academic expert like him.
What Wallace has gave us is a complete manual explaining the path of shamatha practice until the attainment of the first Dhyana (Jhanna in pali).
Using the ten stages system established by the indian scholar Kamalashila, Wallace directs detailed instructions for the practice at the same time developing a very skillful dialogue between buddhist contemplatives methods and the scientists's one.
Each chapter corresponds to a shamatha stage, each one ends with a contemplative practice including the Four Immeasurables and Dream Yoga.In chapter 8 and 9 the Profesor introduce another two differents methods of shamatha as preliminaries to Dzogchen.
According to Wallace without attainment of shamatha it is impossible the achieve vipashyana or more advanced stages of Vajrayana neither. Shamatha is the foundation stone of all those practices
Wallace has the neurosurgeon precision when meditative instruction is about. The book itself is a supporting tool for all those who has the capacity to enter into several years of strict retreatment. And you can complement it with Dreaming Yourself Awake: Lucid Dreaming and Tibetan Dream Yoga for Insight and Transformation
I'm very grateful to him for have written this book, which us fundamental text for all of us following the Yogi path.