Authored by the Catalonian mystic and occultist Vicente Beltrán-Anglada (VBA, 1915-1988), this is the first English translation of this introductory book on Agni Yoga (initially published in 2017; revised and extended in 2019). This book presents a practical exposition of the mystical but intensely dynamic life born in the heart when the mind stops reflecting its external circumstances and surrenders to its spiritual purpose.Students of the modern practice of mindfulness may find in VBA's approach to Agni Yoga a striking resemblance with the constant presence of mind (i.e., profound attentiveness) required of its practitioners. Students of the evolution of consciousness may find in this book a cogent exposition of VBA's personal experience in developing the intuitive sense of the heart beyond the rational mind.Appendices, with illustrations, have been added to enhance the comprehension of this material for those fellow students and scholars interested in the esoteric context in which VBA's approach to Agni Yoga was written.