"A Series of Lessons in Raja Yoga" is a spiritual and instructional book written by William Walker Atkinson. Published in the early 20th century, the book provides readers with a comprehensive guide to the practice of Raja Yoga, which is one of the classical paths of yoga outlined in ancient Indian philosophy. Raja Yoga, often referred to as the "royal path," focuses on the cultivation of mental and spiritual discipline.

Atkinson, a prolific writer in the New Thought movement, explores various aspects of Raja Yoga in a systematic and accessible manner. The book is structured as a series of lessons, each designed to guide the reader through the principles and practices of Raja Yoga. Some key topics covered in the book include: Control of the Mind: Atkinson emphasizes the importance of mastering the mind through concentration and meditation.

The book provides practical exercises and techniques to develop mental focus and clarity. Breath Control (Pranayama): The author delves into the significance of breath control as a means to regulate the life force (prana) within the body. Pranayama exercises are explained to help readers harness the power of breath for physical and mental well-being. Meditation: A substantial part of the book is dedicated to the practice of meditation.

Atkinson introduces various meditation techniques and provides guidance on how to attain inner peace, self-realization, and spiritual awakening through consistent meditation. Ethical and Moral Guidelines: Raja Yoga places importance on ethical and moral conduct as a foundation for spiritual growth. Atkinson discusses the principles of right living and the importance of cultivating virtues. The Higher Self: The book delves into the concept of the Higher Self or the Divine within. Atkinson explores the idea of realizing one's true nature and connecting with the higher aspects of consciousness.

"A Series of Lessons in Raja Yoga" is characterized by its practical approach, making it a valuable resource for individuals seeking a systematic guide to the practice of Raja Yoga. It blends Eastern spiritual wisdom with Western esoteric teachings, offering a bridge between these two perspectives for readers interested in the pursuit of spiritual development and self-realization.