Advaita Vedanta is a Sanksrit name for the philosophy of non-duality.
The Advaita in Advaita Vedanta
Advaita means non-dual (a-dvaita). According to this view, reality is a perfect whole or absolute oneness. Even the word 'oneness' suggests something with a limit or boundary, so the philosophers of Advaita Vedanta prefer the term 'not two'.
It follows that if this is the reality in everything, then it is the reality in each of us. Which suggests that somehow, we ought to be able to find it!
So the philosophy of Advaita Vedanta is closely connected with the Way of Self-Knowledge Adhyatma Yoga, which is the practical methods of discovering this reality in our own being.
One of those methods is meditation. Another important practice is to reflect carefully about the idea that all is one (or rather, not two), and what that means for who we really are. Thus part of the practice of Adhyatma Yoga is to think seriously about the theory of Advaita Vedanta. If we conclude for ourselves that there is a perfect universal wholeness underlying our own being, we will be strongly incentivized to look for it!
That there is one ultimate reality is an entirely rational and logical point of view. It resembles in some ways what western philosophers have called the 'noumenal' or the 'absolute'. However, western philosophers have been speculating about what reality might be like, while the original teachers of Advaita Vedanta were indicating what they had discovered within themselves, with the aim of helping others to do the same. As such Advaita Vedanta is not so much concerned with speculation and abstractions.
The Vedanta in Advaita Vedanta
Vedanta means 'of the Vedas', meaning the texts in which knowledge has been recorded. So Advaita Vedanta means the non-dual interpretation of the revealed texts of wisdom and knowledge. When the term 'Advaita Vedanta' was first used, 'Vedanta' referred to the Indian Vedas because that is what was known to those who used it at the time. However it extends equally to the texts of all the wisdom traditions and universal knowledge.
Schools and Teachers of Advaita Vedanta
Advaita Vedanta was expressed in its present form by the great philosopher-sage Shri Shankara, who lived in India probably in the 8th century CE. Shankara showed how Advaita Vedanta could explain the true meaning of all the revealed texts as pointing to the same truth, where the other schools of thought led to inconsistencies.
Shankara was found to have done this so well that previous formulations came to be neglected. Since then, some writers on Advaita Vedanta have differed in some ways from Shankara. Others have carefully remained consistent with Shankara's teachings while considering further details or addressing new situations.
Over time, departures from Shankara's views have been found to lead to difficulties, while those which adhere to Shankara's presentation have been able to accommodate developments without compromising the principle that Reality is not two.
Shri Shankara's presentation is still the most widely accepted understanding of Advaita Vedanta. Sometimes the term 'Traditional Advaita Vedanta' is used to refer to teachings which are entirely consistent with those of Shri Shankara, although, in general, Advaita Vedanta is understood to mean the teachings as presented by Shri Shankara and his followers anyway.
The founder of Shanti Sadan, Hari Prasad Shastri, belonged to a line of teachers of Advaita Vedanta in the tradition of Shri Shankara. All the material site on this site is about this philosophy and the methods of Adhyatma Yoga, and the connections with other schools of wisdom.
Examples of Non-duality according to Advaita Vedanta
The most important questions that non-duality deals with are the apparent differences between Self and Other, and between Humanity and the Absolute, or the divine.
At the basis of the human condition seems to be the all-important difference we feel between 'me' and everything else. Most of the challenges of life are concerned with making connections with others and dealing with apparent conflicts of interest.
And for philosophers, theologians, and some scientists, a central question is how we as individual human beings relate to what might be called 'The Absolute' or 'God' or 'Total Reality'.
The practical problems of finding happiness in life, and the great philosophical questions, arise because of these apparent differences.
Advaita Vedanta explains how these differences do occur in the world as we experience it through our minds and senses, but do not affect the absolute or transcendent Reality. This provides a rationally consistent world-view. And Adhyatma Yoga offers ways of discovering the Reality that underlies our minds and senses.