The Doctrine and Practice of Yoga Including the Practices and Exercises of Concentration, both Objective and Subjective, and Active and Passive Mentation, an Elucidation of Maya, Guru Worship, and the Worship of the Terrible, also the Mystery of Will-Force

"The Doctrine and Practice of Yoga" by A. P. Mukerji is a guide that gives tips for yoga and personal growth. Written in the early 1900s, the book shows how to do different types of yoga, helps with focus, and talks about growing spiritually. It stresses how important it is to look inside yourself to find out who you really are and understand things better. The story starts by talking to people who are starting to learn about yoga, pointing out that the lessons are short but deep, that it takes time to grow spiritually, and that these lessons connect to other spiritual writings. The beginning part explains concentration, comparing focusing on things outside yourself (like achievements) to focusing on things inside yourself (like spiritual understanding). The author believes real strength and understanding come from looking inward, calling these two types of concentration key to learning spiritual ideas and controlling your mind. This beginning part gets you ready to learn more about ways to make your mind and spirit stronger.