• When he utilizes combined energy, his fighting men become as it were like unto rolling logs or stones. For it is the nature of a log or stone to remain motionless on level ground, and to move when on a slope; if four-cornered, to come to a standstill, but if round-shaped to go rolling down.

    Sun Tzu, Julius Caesar, Einhard, Niccolò Machiavelli, Carl von Clausewitz (2016). “Strategy Six Pack”, p.15,