This book can be called as a prequel to the book "Raja Yoga Yatra 1" by the same author. Before understanding the purpose of Raja Yoga and its eight limbs, we must understand the nature and workings of the mind. Once we become aware of the stages and functions of the mind, management of this powerful mind becomes more plausible through techniques of Raja Yoga.
The author states that life is an expression of the mind - it guides every action, reaction, idea, thought, desire and expectation. Since it plays such a pivotal role, understanding its nature and behavior is so crucial. The mind is the manifest aspect of consciousness and it comprises of four functions. The correlation of these 4 functions with their respective tattwas (elements) is such an eye-opener:
Ahamkara (Ego) - Earth
Chitta (Memories) - Water
Buddhi (Intelligence) - Fire
Manas (Fickle mind) - Air
The author elaborates on these four functions in detail and how to manage each of them. He then explains the different vrittis (mental modifications) with a particular focus on those five vrittis as mentioned by Sage Patanjali in Yoga Sutras. The explanation of why Patanjali emphasized vritti nirodha (cessation) and not opposition or suppression was so insightful.
Mind is classified based on its quality and nature and how it is experienced. It is considered the sixth sense organ. The mind can also be classified based on its states as understood by modern psychology. The fourth state - Turiya (transcendental or superconscious mind) is where the mind breaks all its barriers, there is no separation between the external world and the internal world and it becomes so powerful that it can influence the outer environment.
Though these chapters might seem theoretical, they help to gain deeper awareness about one's mind and its default workings.
The mind is understood in the form of a portal, a doorway that connects transcendental reality and material reality. The mind can help you go towards either side, depending on what you pursue. The highest sadhana in life, according to the author, is mind management, not meditation. The highest awareness is how the mind responds to different situations.
The eight limbs of Raja Yoga are then explained in detail and their respective role in mind management.
This is a text to be studied and contemplated over, with multiple re-reads. I'd highly recommend this book for Yoga practitioners and for anyone who would like to explore the workings of the mind.