“The onset of troops is like the rush of a torrent which will even roll stones along in its course.”
A moving force sweeps obstacles that static strength cannot; build motion, then let it do the work.
Chapter 5 turns from combination to physics: the onset of troops is like the rush of a torrent which will even roll stones along in its course. Momentum enters the book here as a first-class strategic quantity — force in motion accomplishes what the same force stationary cannot, and heavy things (stones) join a current they could never start. Sun Tzu’s army is not a wall but a river.
A newsletter starts as a trickle — one post a week, twenty readers. But each issue is designed to be forwarded: genuinely useful, no login, clean formatting. By month six, forwarding is doing the acquisition; by year two, the "marketing budget" is the momentum itself, and launches to the list move markets the way a torrent moves stones. The heavy objects — product launches, a book, a conference — get rolled along by a current the author merely maintains.
Momentum is not busyness — a furious hamster wheel rolls nothing. The torrent verse requires directional flow: motion that accumulates and carries, not activity that repeats and dissipates. Before crediting your "momentum," ask what stone it has actually moved lately; if the answer is none, you have churn wearing the costume of a current.