It’s been ca. two thousand years since Yoga Sutras was written. Within this period the work has been translated into a good number of various languages, while the number of commentaries on it is countless. It was India alone – ancient and medieval – that provided for at least a dozen of very detailed (to say the least of them) and thorough commentaries on Yoga Sutras: Yoga-Bhashya of Vyasa (ca. 450 AD), Tattva-Vaisharadi of Vacaspati Mishra (ca. 850 AD), Raja-Martanda of Bhojaraja (ca. 1019-1054 AD), Yoga-Bhashya-Vivarana of Shankara Bhagavatpada (ca. 1350 AD), Yoga-Siddhanta-Candrika of Narayana Tirtha (ca. 1350 AD), Yoga-Varttika of Vijnana Bhikshu (ca. 1550 AD). And there must be a lot of other commentaries that are not known to me.
Yoga Sutras was analyzed by philosophers and systematicians of Indian philosophy, like Mueller and Radhakrishnan.
In scope of European tradition Yoga Sutras (in addition to professional Indologists) was studied by such big heads as Mircea Eliade.
Beyond the scope of scientific community they were the mystics of various European Traditions, including Annie Bezant, Alice Bailey and Aleister Crowley , who were trying to understand it.
I know about ca. a hundred of this text translations into English. So one would think – is it possible to add something conceptually new and do we really need a new translation and commentary? So I shall take the liberty of stating that not only it is relevant, but it is also necessary. And it is right now that it’s become feasible.
The main reason of it is that it was until the recent century that European knowledge about human psyche lagged far behind the oriental one. The same is referred to psychological techniques. Indeed, if we compare, for instance the Spiritual Exercises of Ignatius of Loyola or the concepts of Meister Eckhart with Buddhist or Tantric practices we will immediately see that European traditions were mainly dealing with conscious sphere of human psyche, and their “dive” into subconsciousness was very shallow. Accordingly, European languages lacked the adequate set of terms for description of complex intra-psychical processes and psycho-techniques. Thus all translations of Yoga Sutras, as well as of other treatises, into European languages were somewhat petty. Something was missing there, but it was impossible for this something to be present just because our European paradigm of human mind was missing those adequate words and concepts. But in early 20th century the situation started to change drastically. Having more or less figured it out with the matter, the Western world with all the research ardency so characteristic of it pounced on the field of psyche. They launched scientific psychology that was followed by psychotherapy. The psychoanalysis later followed by post-psychoanalytic Schools elaborated complex psychological techniques and practices addressed to one’s unconscious mind. There emerged a rather complicated language used for description of intra-psychical processes. It was further upgraded when cognitive activity reached for the sphere of collective unconsciousness, study of archetypes and so on. And then once again became more sophisticated after emergence of transpersonal psychology that came to grips with study of the spiritual experience that had been previously inaccessible. The Western science started to reveal its interest to mystic experience while the Western mentality started to generate the language for its adequate description.
Another determining factor was the worldwide expansion of Western culture and its active “digestion” of other cultures. A great number of manifold sources dedicated to various spiritual psycho-practices, the sources that had been previously closed or even secret, were now available. Subject to his desire, a Western scientist (or even a non-scientist – also subject to his desire J) can read more primary sources on this or that Tradition than an authentic bearer of this tradition actually does. The opportunity to compare that had been missing for millennia was now available, also meaning the opportunity of better understanding. And, once again, the chance of improving the description languages in particular.
The reader might have already got what I’m driving at. Yes, the Western understanding of psyche was far behind the Eastern one. But this was the past. Today the language of modern Western psychology is more than sufficient for description of classical psycho-practices of ancient world, and in many aspects it even excels the languages used in old times. This does not make the mystic experience of Yoga founders less valuable. On the contrary: the mystic experience abides beyond time and description languages, so that each new language only makes it possible for us to understand its core better, and hence - to adjust the practice.
The situation in some way resembles me of relations between Ayurveda and Western medicine. Fifteen hundred years ago Ayurvedic doctors were able to perform operations that the Western medicine rose to only at the end of the 19th century (like rhinoplasty, for instance). But – it did rose!! And now, with hand on your heart, tell me where you’d prefer to be in case of medical emergency: in the cell of an Ayurvedic doctor redolent of herbs or in a Western clinic equipped with state-of-the-art facilities? Yes, when you’re young and healthy, taking panchakarma might be pleasant… But when it goes about life and death… The Ayurveda experts still know a lot of herbs and compositions that the Western doctors have no idea about. But let us be realistic – the conceptual knowledge of the Western science is still much more profound.
Another factor that we should also take into account is that European mysticism, just like Europe itself, was not marking time. Mystic traditions in general tend to develop (or, unfortunately, degrade) together with cultures that they were begotten by, and the instance of India comes as a good confirmation of this. The Western culture has made a lot of interest attempts, acquired much experience that was not available for the East, and within these systems (for it is not yet time to refer to them as Traditions) the specific languages for description of psychological and spiritual experience have emerged. Relying upon this experience may also come as a good support in understanding the primary sources of ancient times. Of course there is a whole class of orthodox intellectuals of Yoga who speak slightingly of holotropic breathwork, show aversion when refer to New Age and implore Osho not to discredit good name of Authentic Tantra, but don’t they debar the Universe, Yoga and Tantra of their development? For they are the non-traditional concepts that give rise to new traditions, while reckless and radical experiments become the ground of new knowledge. In some aspect European mysticism undergoes the stages that the Indian one experienced at the period of Buddha and Axial Age, and then once again in Middle Ages. Let us remember, for instance, Shiva Samhita and its outright polemics with other points of view. It means there were a lot of Schools with different views and approaches, and not some “ancient” canon . There were attempts, disputes, search for truth. And what it most important – there was development of the System.
But let us come back to Yoga Sutras. Notwithstanding the development of the Western psychology all translations and commentaries available have been done within the paradigm of the late 19th century. This probably happens because representatives of the related sciences – philosophy, oriental studies, linguistics – cannot at the same time act as psychologists, let alone practicing psychotherapists, as well. Or, rather, they can, of course, but probably it somehow didn’t work out. On the other hand, a case when people who were successful in practicing new or old systems were in parallel dealing with “academic” oriental studies was also rare. That is why the achievements in one field have been extremely late in affecting the other one. YS is translated and commented upon as if there were no Freud, no Jung or Groff, nothing of all those social disruption and insights.
Since I am a profession psychologist by vocation and degree, an expert in the field of psycho-practices by the focus of my investigations, a physicist by the mode of thinking and a practicing mystic by my spirit, I intend to close the gap and to try to comment upon Patanjali’s treatise basing upon the language of modern psychology, upon understanding of mystic, occult and esoteric systems and Traditions  other than Yoga, and upon actual practice of Yoga as well.
 I feel free to mention these names here, though these people hardly “have a high rating” in scope of scientific community. Moreover, they are not scientists and their interpretations have a lot of flaws. But they are mystics. And who can have a better understanding of a mystic than another mystic?
 Those who are interested in spiritual disputes of India in the time of Buddha may read about them in the books of Shokhin.
 You may find my opinion about the difference between occultism and esotericism in my monograph “Religious Psycho-practices in the History of Culture”.