Marshall Rosenberg was the stern-faced creator of nonviolent communication, a man who spent his life finding ways to eradicate hate.

Often armed only with his trademark giraffe and jackal puppets, Rosenberg toured the world teaching a new way of speaking. Language was key, but to discover the meaning of the puppets you'll have to tune in.

Championing Marshall Rosenberg is comedian and author, Tony Hawks.

A sceptical Matthew Parris presents while David Baker of the London School of Life fills in the biographical gaps.

Produced at BBC Bristol by Miles Warde

First broadcast on BBC Radio 4 in August 2016.