The philosophy of Non-duality, or as it is called in India, Advaita-Vedanta, says that there is just One Spirit in the Universe, and that everything, living or inanimate, is an inseparable and indivisible part of this One Spirit. Nonduality further says that it is only illusion, caused by the mind and the play of the senses, which make us regard the world and everything in it as real and separate from us.
For someone not familiar with this philosophy, it might sound strange and even weird, but once understood, it can completely change one's attitude and perspective about life.
Imagine a state in which you feel oneness with the Universe, enjoying bliss and peace of mind, and at the same time acting and functioning normally in your day-to-day life. A state of being active in the world, yet maintaining a state of inner detachment. In this state you are aware of your oneness with the One Spirit, and also aware that the One Spirit is acting and manifesting through everything; things, plants, trees, animals and people. This is the experience of nonduality in its highest condition.
Ordinarily, the veil of thoughts and the five senses draw the mind outside, to the external world, and obscure the awareness of the consciousness that is beyond the mind. Meditation brings peace to the mind and develops the ability to silence it, thus enabling us to experience the "state" of nonduality. In this state of inner silence, one rises above the illusion of identification with the mind, thoughts and ego, gets beyond the illusion of separateness and realizes oneness with the One Spirit. It is as if a new sort of consciousness dawns, and one sees the world in a different way.
With this kind of consciousness, we are able to allow the mind to be active or command it to be silent at our command. It becomes our faithful servant, instead of being our master. We function very effectively in the outer world, yet our basis is in pure, calm and limitless consciousness, which is not attached to anything and not limited by anything. In this state, we live and view the world from the nonduality point of view.
Though in our day-to-day life we refer to other people as separate from us, this is only a mental viewpoint, convenient for functioning in our daily lives. From a higher state of consciousness, all are One, and the terms "I", "you", "he", "she" and "they" are not real. There is only the One Spirit, Consciousness, which seems to manifest in limitless forms and ways.
The concept of nonduality is not a strange or weird idea. It can be experienced and lived right here and now, no matter where you are, and without attracting anybody's attention. It is an inner state of consciousness, not an external state.
It is possible to realize the meaning of nonduality and attain spiritual awakening and enlightenment in an ashram or a cave, and it is also equally possible to do so while living in a town or city with family and job. It is all a matter of strong desire, inner attitude and dedication.
Most people cannot afford to live a secluded life in order to meditate and lead a purely spiritual life. Most of us need to work and support a family, and can therefore devote only part of the day to spiritual pursuits. The good news is that we can practice meditation and realize our true being without abandoning our present style of living. With proper planning it is possible to find the time and the energy.
Meditation, walking on the spiritual path and the realization of nonduality can be practiced anywhere, without making external changes in our life. You can stay with your job and family, and still make spiritual progress and realize the true meaning of nonduality.
There are many shades of meaning to the word nonduality. As an introduction, we might say that nonduality is the philosophical, spiritual and scientific understanding of non-separation and fundamental oneness.
Our starting point is the statement “we are all one,” and this is meant not in some abstract sense but at the deepest level of existence. Duality, or separation, between the observer and the observed, is an illusion that the Eastern mystics have long recognized and Western science has more recently come to understand through quantum mechanics.
Dualities are usually seen in terms of opposites: Mind/Matter, Self/Other, Conscious/Unconscious, Illusion/Reality, Quantum/Classical, Wave/Particle, Spiritual/Material, Beginning/End, Male/Female, Living/Dead and Good/Evil. Nonduality is the understanding that identification with common dualisms avoids recognition of a deeper reality.
How can we better understand nonduality?
There are two aspects to this question, and at first glance they appear to be mutually exclusive, although they may be considered two representations of a single underlying reality.
The first aspect is our understanding of external reality, and for this we turn to science. The word science comes from the Latin scientia, which means knowledge. The beauty and usefulness of science is that it seeks to measure and describe reality without personal, religious or cultural bias. For something to be considered scientifically proven it has to pass exhaustive scrutiny, and even then is always subject to future revision. Inevitably human biases creep in, but the pursuit of science itself is intrinsically an evolving quest for truth. But then quantum mechanics turned much of this lauded objectivity on its head, as the role of the observer became inseparable from the observed quantum effect. It is as if consciousness itself plays a role in creating reality. Indeed, the two may be the same thing. As quantum pioneer Niels Bohr once put it: “A physicist is just an atom's way of looking at itself!”
The second aspect is our inner, personal experience of consciousness, our “awareness of awareness.” We have our senses to perceive the world, but “behind” all perception, memory, identification and thought is simply pure awareness itself. Eastern mystics have described this undifferentiated consciousness for thousands of years as being the ultimate state of bliss, or nirvana. Seekers have attempted to experience it for themselves through countless rituals and practices, although the state itself can be quite simply described. As Indian advaita teacher Nisargadatta Maharaj said: “The trinity: mind, self and spirit, when looked into, becomes unity.”
The central challenge to understanding nonduality may be that it exists beyond language, because once it has been named, by definition - and paradoxically - a duality has been created. Even the statement “all things are one” creates a distinction between “one” and “not-one”! Hardly any wonder that nonduality has been misunderstood, particularly in the West.