This volume discusses the three next steps of Yoga known as dharana, dhyana and Samadhi. They represent the crux of the process of yogic sadhana. In view of the extreme subtlety of these steps, this volume indicates to the ways and means leading to successful coverage of these steps through relevant texts dealing with this part of the sadhana. With this end in view, selections have been made from such yogic texts bearing as the Upanisads, Bhagavadgita, Vijnanabhairava, Malinivijayottaratantra, etc. which have been adduced here along with their English translation and necessary notes wherever required for clarification. It also includes and discusses the Epistemology of Yoga as well as a digest of the entire process and method of the sadhana put together succinctly and in a graded manner under A Tractatus of Yoga. The formulations made here are for summarizing the entire range of the sadhana in as brief a form as possible. These formulations have been made somewhat on the pattern of the classical authors of the sutra-form of literature dealing with subjects of utmost technical bearing requiring close attention in the process of formulation of the tractatus here from that of the ancient Sanskrit authors of the sutras lies in the fact that while sutra preceded their expositions made sometimes by the sutrakaras themselves and mostly by other exponents of them quite subsequently, here the formulations only follow the detailed exposition meant particularly to serve as a digest of the entire stuff along with all the difficulties involved in its coverage, understanding and practical application. All these ingredients of yoga as well its basic postulates have been discussed clearly and authentically have been discussed clearly and authentically having based on the textual verity on the one hand and scientific possibility on the other. All these ingredients of yoga as well its basic postulates have been discussed clearly and authentically having based on the textual and authentically having based on the textual verity on the one hand and scientific possibility on the other. The book is designed to confirm to the course contents of Yoga and we hope that it will be of great use to graduates, post graduates, diploma, research students, teachers of Yoga and general practitioners alike.