The first person to consolidate the principles of Advaita was Shankara (Ādi Śankara, आदि शंकर, pronounced /α:di shənkərə, 788–820 CE). He is ... known as Śankarāchārya (शंकराचार्य, pronounced as /shənkərα:chα:ryə/). Continuing the line of thought of some of the Upanishadic teachers, and also that of his own teacher's teacher Gaudapada, (Ajativada), Shankara expounded the doctrine of Advaita — a nondualistic reality. According to Advaitins (followers of Advaita), Shankara exposed the relative nature of the world and established the supreme truth of the Advaita by analysing the three states of experience — being awake (vaishvanara), dreaming (swapna), and being in deep sleep (sushupti). The supreme truth of the Advaita is said to be the non-dual reality of Brahman, in which atman (the individual soul) and Brahman (the Supreme Consciousness) are identified absolutely.