Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Did you know that the Upanishads are filled with secrets and mysteries? Well, this is fact! Vedic disciples have advanced that they acquired knowledge and wisdom by means of the Upanishads which have been taught to them by the scholars and seers. It is vital to note that there are 108 Upanishads. Besides, there are 10 main Upanishads - Isha, Kena, Katha, Prashna, Mundak, Mandukya, Aiteraya, Taittiriya, Chhandogya and Brihadaranyaka Upanishads. All the questions without answer can all be told by the scriptures of the Upanishads which are known to be divine by nature. The Upanishads' deepest truth is its teachings which say that everything is God. That which cannot be expressed by speech, but by which speech is expressed - that alone is known as Brahman (God). Brahman cannot be perceived with the mind but the mind is perceived by Brahman!