Clay is fashioned into vessels; it is on their empty hollowness that their use depends. Doors and windows are cut out to make a dwelling, and on the empty space within, its use depends. Thus, while the existence of things may be good, it is the non-existence in them that makes them serviceable.
LaoziArms are instruments of ill omen, not the instruments of the gentleman. When one is compelled to use them, it is best to do so without relish.
Laozi