This came up in a non-spiritual forum and I thought it worth sharing here.
I would suggest there’s a big difference between taking on a philosophical position that we’re all one and actually living it. Too much of the first becomes a denial of our experience and a defence of beliefs. It also muddies our understanding. There are a number of texts, old and new, that describe the lived experience but such things are not meant as something to believe but rather serve as a map of the territory. (if you’re in Cleveland, you don’t use a map of Pittsburgh to get around)
One of the issues with consciousness is that it’s not a physical thing so it can’t be studied using purely physical means. Some people see consciousness as an effect of physical processes (like brain function) but it doesn’t take much research to find examples of where that doesn’t hold true. “Witnessing”, for example, where one observes the conscious states of the physiology shifting – the body and mind fall asleep but we remain awake within. Or the experience of pure consciousness in deep meditation or profound experience.
One of the useful things the “ancients” offered was systematic ways of exploring consciousness directly, such as through some forms of meditation. In other words, its not just philosophic musings.
There has been a variety of research more recently into what are coming to be called Transpersonal stages of development or stages of development within consciousness itself. A friend of mine did her PhD at Sofia on the subject. From an eastern perspective, they describe this as recognizing we are consciousness rather than being a body or mind. The state of the physiology no longer overshadows our awareness. There is a continuum of awareness underlying all temporal experiences. This is nothing like a disassociative state and can be verified by it’s unique EEG signature that includes the alpha of wakefulness overlaid on the delta of sleep.
There is of course a 2 way street. The shifts in physiological state (waking to sleep, etc) still certainly impact what is experienced but the experiencer is no longer overshadowed.
Yes, it’s true that there are a zillion ways some of this is experienced. To me, part of what has been missing is a broader model that allows us to put it all in context. For example, some of what you’ll see described is a passing experience interpreted in some personal way. Some of it is put into a cultural or religious context. Some of it is an actual shift in sense of self, a developmental change that stays like the above. Having more robust models can help sort these kinds of things into more context. It can also clear up some of the current confusion, such as around oneness and non-duality. This is not just taken as a belief but also confused with Self Realization. Oneness is actually a later stage.
Often, spiritual traditions, religions and philosophies grow out of the experience of one or a small group of people. Placed in the context of a more inclusive model of human development, apparently conflicting descriptions turn out to be addressing different stages. A toddler doesn’t see the world the same way as a teen. Neither do people in different stages of post-personal development. Similarly, we all experience puberty in our own way. But that doesn’t mean there isn’t a common underlying process.