Advaita School BeforeSankara
MandanaMisra: Brahman as the only Positive Reality, Admission of Negative Realities like Removal of Ignorance (Avidyanivrtti) and Absence of the World (Prapancaabhava), Analysis of the States of Consciousness in the Mandukyopanisad.
Gaudapada: Equivalence of Dream and Waking States, Metaphysical Interpretation of Dream and Sleep, Theory of Non-Origination (Ajativada), Maya as Projecting (Viksepa) and Concealing (Avarana).
Sankara: Nirguna Brahman, Adhyasa, Rejection of the (unconscious) SankhyanPrakrti as the Source of the Universe, Cetana Brahma as the Non-Different Material and Efficient Cause (Abhinnanimittopadanakarana) of the Universe, Theory of Causation, Nature of the Jiva, Jivanmukti.
Criticism of Other Schools of Philosophy: Sankhya, Vaisesika, Buddhism and Jainism.Tarkapada.
The Teachings of the Prasthanatrayi, The Relative Importance of Reason and Sruti, Jnana as the Means to Liberation.
Post SankaraAdvaita: The Identification of Avidya with Maya, Maya as neither real nor Unreal (Sadasadvilaksana), Avidya as Cosmic as well as Individual, Acetana Maya as the Material Cause and Saguna Brahman (Isvara) as the Efficient Cause of the Universe, Vivatavada, Three Levels of Reality (Sattatraividhhya) and the Theory of Sublation (Badha), Important Differences between Bhamatiprasthana and Vivaranaprasthana, Avacchedavada, Abhasavada, Ekajivavada, Drstisrstivada and Srstidrstivada.
Advaita Theory of Knowledge: Svatahpramanyavada and Pramanas