The simple question ‘How we know?’ is one of the toughest problems that have confronted the human mind. This book presents to modern thinkers the Vedantic approach to this universal problem. It dwells on different types of knowledge from sensory experience to the transcendental perception of the Ultimate Reality. Besides the interpretation of different forms of non-perceptual knowledge it gives an elaborate explanation of illusory experience and the cognition of non-existence. The author has tried to present the views of Advaita Vedanta on this topic in relation to those of other Indian and Western systems of thought.