Non duallists were fiercely attacked by the orthodox schools of hinduism. This led to a tremendous flowering of philosophy in indian philospy. The next burst of development was after shankara chara, when dualists knowd it's within hinduism and attack the non duallists.
Swami Sarvapriyananda gives a discourse on the nature of Maya (Ignorance). This lecture is part of a series of talks inspired by Swami Vivekananda's Jnana Yoga.