This short paper gets deep in the weeds of a particular kind of physics, he is sharing a rare example where we were able to both reduce a system and then construct the aggregate behavior. But the broad systems conclusion is what's interesting.
The arrogance of the particle physicist and his intensive research may be behind us (the discoverer of the positron said "the rest is chemistry"), but we have yet to recover from that of some molecular biologists, who seem determined to try to reduce everything about the human organism to "only" chemistry, from the common cold and ailmental disease to the religious instinct. Surely there are more levels of organization between human ethology and DNA than there are between DNA and quantum electrodynamics, and each level can require a whole new conceptual structure.