A number of Ways (Do), owing to the fact that a Do is a particular expression of the Way of the universe itself, have used the term mu to point to the sum and substance of the universe. And since it is the mind after all that perceives the absolute universe, various mental states in the Ways have appellations that utilize the character for mu as well. Originating in Buddhism, but having parallels in other religions, mu means, “the void,” or “nothingness.”--H. E. Davey, The Japanese Way of the Artist
