Book 3 orients the reader to the autonomic nervous system. The reciprocal model with two states (fight or flight vs. rest and digest) expands to the 3-Layer (Polyvagal) model with six states. Peter Levine’s clinical work and teaching, combined with Stephen Porges research have given us desperately needed tools. This map gives us landmarks to navigate by, pathways to move along and an overview to notice what is sturdy and what is missing. It encourages us toward our very real cooperative, resilient potential. This model is
1. Simple, but includes the details needed to manage the situation at hand
2. Broadly applicable, yet accurate enough to be very useful
3. Easy for most people to learn, use and communicate
4. Attractive – in that it matches people’s experience, and it is easy to look at.
The book includes maps of what the six landmark states look and feel like, and introduces some of Stephen Porges’ polyvagal vocabulary. 
