Choosing between calming someone down and shifting their nervous-system state.

The book's entire theory of change in one image. The three circuits are hierarchical — ventral vagal on top, sympathetic in the middle, dorsal vagal at the bottom — and switching on the top circuit actively inhibits the lower two. You don't fight stress or argue with shutdown; you activate social engagement and the brake does the rest. That is why Rosenberg's clinical program is "restore ventral vagal function first, then do everything else" — and why "it is not necessary to go up the ladder one step at a time from shutdown to stress and then from stress to social engagement. Ventral vagal circuit activity moves a person directly from shutdown and emotional depression all the way up to a ventral vagal state."