The All (Oneness)

In Hermetic philosophy, the single largest, most important, unifying idea is that all is one. There is only one thing. (Uni)verse is a great term for it. If you subscribe to the Big Bang theory, which I do, than all was one point in the beginning, and most likely "before" it. Zero is not a number, but it is the source of all of them. Zero does not exist, because it is the lack of existence, it is nothing, or nothingness. When nothing becomes something, it is one thing. It was one thing before, if you want to say that nothing is one thing. From our perspective, using logic, the source of our existence is awareness. Once we are aware, we become aware of our surroundings, and than, due to our brain capacity, we become aware of ourselves. We cannot say when awareness started, or when it ends, we can only when self awareness starts and ends. So we can say that awareness is above time, relative to us at least. If awareness is above time, it is before creation, and therefore is the One Thing, The All, in us. Awareness, also, does not act, it simply is. Being is its nature, not being this or that, but being, and being is the root of all. The Thing I am describing has no word for it, but all words describe it. As the Tao Te Ching says:

"The Tao that can be told is not the eternal Tao
The name that can be named is not the eternal name.

The Tao is both named and nameless.
As nameless it is the origin of all things;
as named it is the mother of 10,000 things..."

The All is all there is. The All is in all, and all is in The All. It is the most inclusive, basic, general, archetypal idea of God. There cannot be anything outside of it. 

In Hermetic philosophy The All is thought of as Mind. That all mind is one mind, and all mind is The Mind. This does not mean a personality as the Abrahamic religions see it, as The All is all personalities and possibilities. The physical world could be thought of as the "body" of The All. In Hermetic philosophy everything is seen as a mirror image of The All, hence I say everything has awareness. Just as The All everything has a body and has Mind. Now there is Mind, and mind. Mind is The All Mind, mind is the limited physical mind we humans have. The only difference is that one is restricted and one is not, but we still have both. The Greater Mind, which could be thought of as the collective consciousness of all there is, is the higher self, super ego, holy guardian angel...but mind is the ego as we know it in psychology. It is the mediating space of mind through which awareness communicate to the body. When this mind/ego becomes aware of its own existence it usually identifies with the less subtle, and more superficial self, the body. When this happens the thing suffers as change is the only physical constant. But when we identify with the awareness, our true essence, we do not suffer with the body, and find true freedom. The mind is able to be clear and when we identify with the Mind, mind and Mind become one. This is Superconsciousness. So, in conclusion, Oneness can only be known by unspecifying, and peeling back the layers to the source, and there is only one source of everything, it is One.