The Upanishads are Hindu scriptures that focus on the following questions: 1. Who is God?  2. Who am I?  3. What is my relationship with God?  4. What are the characteristics of God?  5. How is Soul and God related? This chapter on Hinduism also summarizes the three states of existence of living beings– Jagruti, Swapna and Shushupti which are linked to the concept of body, mind and soul and how the soul is the ultimate God. Further, the chapter also covers the different schools of thought on Brahman (God)

Based on the concepts relating to Gnana Maarga in Vedas ,various Rishis have expounded and analysed the concept of Brahman and these are called Upanishads. •There are more than 100 Upanishads out of which 10 to 15 Upanishads are quite famous. •The key questions analysed in the Upanishads are under: Who am I? – is it my body or my mind or something beyond this. Who is god? - is it within me or outside of me, is it separate or is it all-pervasive. What is my relationship to god ? What is the characteristics of the god? Whether it has form, fragrance etc etc. •These questions are analysed through deduction and elimination process in different Upanishads in different ways  •One of the ways in which it is established that there is something which activates the body and mind is as under: There are three states of Human existence as under: 1. when a person is awake (called Jagruthi) 2. When a person is sleeping and in dream ( called Swapna) 3. When a person is in deep sleep (Sushupthi) When somebody is awake, his inner organs (gnanendriyas) relating to various feelings such as pleasure, fear etc are activated by the actions of his various organs (eyes, ears, mouth, hand etc) called karmendriyas When he is in dream (Swapna) even though his karmendriyas are idle and not working, he still perceives pleasure, fear etc through his mind directly controlling gnanendriyas. This shows that the mind is independently working even when body is at sleep. In deep sleep (sushupthi) even the mind is at rest but when he gets up the next day he is able to realize himself and understand upto the previous sleep what all had happened. This shows that there is something beyond body and mind which keeps a tab of all these and which makes the body and mind to act.  •The Hindu Philosophy calls this as the Soul of the person. Thus the existence of the soul beyond body and mind is proved by one of the Upanishads. •There are discussions in various Upanishads about what happens to the soul after death of a person ; as per Upanishads when a person dies only his body dies and the soul is eternal. •There are various discussions as to whether the soul of each person is individual or is it part of cosmic soul. These discussions lead to evolving of various philosophies like Advaitha, Dvaitha and Vishitadvaitha as we will see later. •In Taitreya Uapnishad the god (Brahman) is defined as the one : •from which every living being in the world has come •Because of which every living being in the world lives. •To which every living being in the world goes back once it ceases to exist •Against this definition various items such as Anna (food) , Prana (breath), Mano (Mind) and Ananda(bliss) are compared to find that everything is God.