The philosophy of advaita, literally non-dualism, is the premier and oldest extant among the vedAnta schools
of Indian philosophy. ShankarAchArya is arguably the most important philosopher in the history of advaita.
shankara
bhagavatpAda
What is Advaita?
Advaita means 'non-duality'. Non-duality means....
We see lightness and darkness,
We hear sound and silence,
We feel pleasure and pain,
We taste sweetness and sourness,
We smell odour and freshness,
We know good and bad,
We experience in differences.
All are subjective. All we see, hear, feel, taste, smell, know, experience, ... we interpret as objects, where we ourselves are subject. We are concerned perhaps too much with what we are conscious of, and forget the miracle of consciousness itself: a flow from many rivers into the ocean.
-Ramana Maharshi
Vedanta
Within you is the spring of all joy. This knowledge, and the steps to realize it, is the science of Vedanta, enshrined in the original spiritual texts of India. The abiding knowledge of Vedanta rests in the vision of the One Reality, a vision that transcends race, class, creed, gender, and nationality. Vedanta is the one principle of truth encompassing all religions.
Ignorance of your essentially happy nature is the cause of all dissatisfaction and unease. Through rational analysis, Vedanta lifts the veil of ignorance to reveal the source of all happiness and fulfillment, namely, yourself. The teachings of Vedanta are profound, yet simple; completely personal, yet universal; and, above all, relevant in today's world.
The entire scheme of Vedanta is to make man progresively happier and more contented in his day-to-day life, so that spiritual unfoldment will take place automatically within the individual. Self-realization is not a sudden superimposition of a particular knowledge; it is the culmination of the evolutionary process in man.
- Chinmayaananda