"Though all is one, none is one." One of my favorite topics and form of spirituality is the belief in balance. In a way we are all one. This is because in a deeper level we are all made of the same thing: molecules(and some people think stardust as well). Our cells are made of molecules. Matter, is just a speeding vibration that manifest itself unto this reality(a little more metaphysical here). In a sense of way we are all connected.
But none is one. This isn't to say that we are all disconnected. This is to say that everything that comes in life and nature has their duality(philosophically this means an opposite). Good and evil(one I don't believe in so much), destruction and creation, happy and sad, tensed and relaxed, darkness and light and so on...
In a deeper level, there is no opposite, there is only a reaction to an action. Basically all is one in that theory. And at the same time, you cannot have light without darkness and you cannot have darkness without light. That is to say, none is one. This is a very interesting philosophy that can mean so so many things and can go very deep.