Atma Bodha, is an auxiliary text written in the Eighth Century by a great sage, Adi Shankacharya, to clarify the fundamental ideas revealed in the Upanishads. It is meant to be studied before an inquirer delves into the Upanishads proper because it teaches the whole system of Vedanta in a straightforward manner, avoiding elaborate arguments. Other texts make sophisticated well-reasoned arguments designed to explain the often cryptic teachings of the Upanishads and negate dualistic and quasi-dualistic views.