This book is the second volume of the Emerald Hills of the Heart series, which brings out a comprehensive and unique examination of concepts and terms associated with Sufism in Islam. In this volume, Gulen looks at fifty different concepts. With an introduction to the heart and some of its dynamics, this work is a rich addition with more gates into spirituality. Concepts examined include freedom, altruism, wisdom, sainthood, intoxication and sobriety, wakefulness, and the universal man.