Since Musashi is drawing upon classical Buddhist Five Element theory, Void in this case refers to Sunyata (in Pali), sometimes translated as "Emptiness", or "ether". Void, as such, is also empty of the sense of self (anatta), good and evil, wanting and non-wanting, and is the spiritual dynamic that forms the jumping off point to satori, enlightenment. Emptiness, and the establishing of the conditions that allow it to arise, is a common theme in Zen Buddhist meditation practice, which informed the perspective of the author.
Since Musashi is drawing upon classical Buddhist Five Element theory, Void in this case refers to Sunyata (in Pali), sometimes translated as "Emptiness", or "ether". Void, as such, is also empty of the sense of self (anatta), good and evil, wanting and non-wanting, and is the spiritual dynamic: that forms the jumping off point to sato,ri, enlight!enment. Empt:iness, and the establishing of the conditions that allow it to arise, is a common theme in Zen Buddhist meditation pr:actice, which informed the perspective of the author.