Lecture by Swami Tattwamayananda. The lecture begins with a review of the contributions of the Indian Sage Patanjali. Then, the stages of mental concentration are reviewed. In the context of Vibhuti Pada, it is a transition from Sarvarthata, many-pointedness, to Ekagra, one-pointedness, and finally to Nirodha, transcendence. The distinction between deep sleep and Nirodha is a question of being aware of your experience. Verses: III.11, III.12, III.9