The basis of reality in this universe is the consideration.
The wall is there because you consider that it is.
If one is inside a body it is because they consider that they are inside a body. One is exterior to a body when one considers that they are exterior.
First there is the consideration, then the resulting phenomena that goes with that consideration.
In order to change considerations, one must be at the same level of the tone scale one was when they first made the consideration and then make a different consideration.