Lecture by Swami Tattwamayananda. Showing the mutual contradictions among the non-Advaitic Schools, establishes the truth of the doctrine of Non-origination. ‘Prakriti,’ the essential nature of things (swabhava) never changes. The four-fold nature of ‘Prakriti’ is explained. Verses: Mandukya Karika 4.4, 4.5, 4.6, 4.7, 4.9