Human cognitive evolution goes through many stages. As we go through this evolution, we go from an egocentric world view in which we cannot separate ourselves physically from the rest of the world. This stage is generally short lived as a baby soon learns that while it hurts to bite its thumb, it does not hurt to bite a blanket. But after we are able to separate ourselves from the rest of the world, we are still unable to to realze that if we bite someone else it will hurt them. In other words, we cannot take on the perspective of another person. To me it seems that this is where solpsism is stuck.
Another way of viewing our evolution is that we go from archaic to mystic to magic and so on. I'll focus on the mystical and magical stages. In the mystical stage, one has develop an understanding of cause-effect relationship. But one is still egocentric, so it is believed that one is the ultimate cause. For example, when a child takes a walk, they think that the sun is moving, but more importantly they think that they are causing the sun to move by moving. So I think it is pretty obvious this is where I think solpsism is stuck, by its own defintion it is. But as one moves beyond the mystical world view, they move into the magical world view. In this space we do not believe that we are the ultimate cause of everything, but that others are (ie Dad, Mom, God, etc).
So we can see that as we evolve we are able to define ourselves as seperate from all other individuals and eventually we can attain the capacity to take on the perspective of others. But instead of becoming more egocentric we become less egocentric as we evolve because we have seperated ourselves from the rest of the world.
But doesn't this seem to lead only to self and not Self? Yes and no. It can if our evolution becomes stagnant. But if we continue to grow, we can see that the Kosmos (not cosmos, but Kosmos which includes everything not just the physical) is a giant holarchy. We are each holons, or part/wholes. We are each wholes of all holons below us (physically, for example, we are made up of organs, which are made of tissue, which are made of cells, which are made of molecules, and so on), and we are part of the holons above us. So as we define our self, we realize that we are just defining part of Self, and that this Self is made of countless holons.
