Another period that marks a new epoch in the development and history of practical and theoretical Yoga is the age of Patanjali (200 B.C. approx.). He is technically called the father of the Yoga literature, even though he does not claim to be the originator.
What he did was really to collect the material into writings which existed before him in some form or the other. According to Dr. S. N. Dasgupta, "Patanjali was probably the most notable person, for he not only collected the different forms of Yoga practices and gleaned the diverse ideas which were or could be associated with Yoga, but grafted them all on the Samkhya metaphysics, and gave them the form in which they have been handed down to us. Vachaspati and Vijnana Bhikshu, the two great commentators on the Vyasabhasya, agree with us in holding that Patanjali was not the founder of Yoga, but an editor. Analytical study of the Sutras also brings the conviction that the Sutras do not show any original attempt, but a masterly and systematic compilation which was also supplemented by findings and contributions. The systematic manner also in which the first three chapters are written, by way of definition and classification, shows that the materials were already in existence and that Patanjali only systematized them. There was no missionizing zeal, no attempt to overthrow the doctrines of other systems, except as far as they might come in by way of explaining the system. Patanjali is not even anxious to establish the system, but he is only engaged in systematizing the facts as he had them."
It is thus clear that, while the general outline of this system was given in the earlier writings, no scientific or direct course of action was shown to attain the state of liberation with such clearness and detail as were necessary. The compilation of the Yogasūtra of Patanjali therefore marks the beginning of an effort to explain, by scientific and valid reasons, the metaphysical and practical basis of the traditional Hindu Yoga, often referred to as the mysticism of India. This Patañjala Yoga is known as Ashtanga Yoga or the Yoga with eight accessories. These are: (1) Yama or restraint, (2) Niyama or observance, (3) Asana or posture, (4) Prāṇayama or the control of the respiratory system, (5) Pratyahara or abstraction, (6) Dharna or concentration, (7) Dhyana or meditation, and (8) Samadhi or trance.
Throughout this work (Yogasutra), in his treatment of the rules of moral conduct and also the supernatural powers (Vibhuti), Patanjali has endeavoured to be extremely thorough and scientific. For example, he argued that continence being confirmed, vigor is obtained (Brahmacharya-pratiṣṭhāyām vīryalābhaḥ). He does not argue or exaggerate that it leads to Kaivalya (aloneness) directly or that a Brahmacharin enjoys the heavenly pleasures in afterlife.
He is practical and direct like the modern scientist, who would easily confirm his belief in favour of continence—that by its practice, man no doubt becomes vigorous. Again he says: "By Samyama (the effort of concentration, meditation and trance in continuity as one single and unbroken process; constraint) over the form of the body, on perceptibility (tadgrāhyashakti) being checked (stambhe), and thus there being no contact with the light of the eye, comes disappearance (antardhānam)." It is interesting here to recall an incident connected with the life of my Guru (spiritual guide) Paramhansa Madhavdasji when I was with him in my early days. It was at about 5 p.m. on February 18th, 1916, when we moved to Matheran, a hilly health resort about a hundred miles away from Bombay, that he disappeared from his chair when an attempt was made to take photos of him. On being asked as to the method by which the disappearance was brought about, he replied in very nearly the same words as those of Vachaspati, who commented upon this Sutra. The explanation as given therein is extremely logical even from a scientific point of view, and the possibility of such an event is granted only on conditions which are rarely possible and have to be fulfilled.
Furthermore, the metaphysical grafting (closely related to the Samkhya tenets) tendered by Patanjali to the various forms of stray and obscure Yoga practices gained for Yoga the recognition of being one of the main systems of Indian philosophy. Thus among the three elaborate philosophical systems included in the great epic of the Mahabharata (200 B.C.), Yoga is also one.