Ādi Śaṅkara was born at a time when Advaita Vedānta Philosophy, one of the principal philosophies to arise out of India was riven with disagreement, impurities, and disarray. In his short life from an early age he re-established the system, reviewed and commented on all the principal works on the subject and travelled the country arguing and winning his case. The system was that those who lost should follow his lead and become his disciples. He then established four philosophical ashrams to follow and maintain the tradition. These four 'seats' in the North, East, South, and West exist to this day, nurturing the teaching and making it available. Of the many books attributed to him all agree that this is genuinely his. It is in two parts - one addressed to the student or disciple and the other to teachers of this philosophy.