When he utilizes combined ...

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.
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.

Quotes from the same author

You have to believe in yourself.
Can you imagine what I would do if I could do all I can?
The supreme art of war is to subdue the enemy without fighting.
“Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.”
“Let your plans be dark and as impenetrable as night, and when you move, fall like a thunderbolt.”