Ajahn Viradhammo reflects on the use of the "Who is thinking" Koan/question. Used during meditation. When one's whole psychological makeup is all about thinking/problem solving only, then doubt will come up. As thinking begets doubt. The depth of spiritual life is about "silence". And one cannot arrive there through thinking. Then one tries to get rid of thinking, and we fall into the trap, of aversion. One has to be able to see thought as an object, in awareness.