Swami Vivekananda is credited with bringing yoga to the West and America. Swami Vivekananda, along with Swami Rama and Swami Satyananda, presents a scientific yet spiritual and practical reading of yoga and meditation. All these renunciates or sannysins were part of old and respected continuous lineages. They all bridged the divide of East and West in passionate ways. No matter who you are, where you live, or what you believe, you do it through the nature of your mind. Raja yoga, the yoga of the mind, is the heart of Patanjali's Yoga Sutras. For those looking for a simpler, lighter, more conversational commentary, we think this one is worth reading. It is also very helpful to read more than one commentary to get different perspectives.
The first Indian edition of this book came out in 1923, and it is remarkable how most of the language still sounds contemporary. In the first half of the book (also based on some lectures given by the author), the author gives a general background for the purpose of raja yoga. Simply and clearly, he states in the introduction:
In acquiring knowledge we make use of generalization, and generalization is based upon observation. We first observe facts, then generalize, and then draw conclusions or principles. The knowledge of the mind, of the internal nature of man, of thought, can never be had until we have first the power of observing the facts that are going on within. It is comparatively easy to observe facts in the external world, for many instruments have been invented for the purpose, but in the internal world we have no instrument to help us. Yet we know we must observe in order to have a real science… The science of Raja Yoga, in the first place, proposes to give us such means of observing the internal states. The instrument is the mind itself. The power of attention, when properly guided, and directed towards the internal world, will analyse the mind, and illumine facts for us. The powers of the mind are like rays of light dissipated; when they are concentrated, they illumine. This is our only means of knowledge.
He goes on a little later to explain the use of this knowledge:
What is the use of such knowledge? … When by analysing his own mind, man comes face to face, as it were, with something that is never destroyed, something which is, by its own nature, eternally pure and perfect he will no more be miserable, no more unhappy.
The next few chapters go on to explain prana, pratyahara, dharana, dhyana, and samadhi with some practical applications. This prepares the reader for the concepts and words in the translation of and commentary on the Yoga Sutras. The commentary is brief and relatively simple, but not so simple that it is stripped of meaning and depth. For more details on the chapter content and the actual Sanskrit text of Patanjali's Yoga Sutras, please refer to the review of Four Chapters on Freedom.
The act of reading and reflecting in itself is a form of meditation. The Yoga Sutras is read periodically, over and over again, over the course of a lifetime. Raja Yoga: Conquering the Internal Nature is a good beginning.