A private zoo owner thought he was taking good care of his bear. Activists say he was torturing her. The epic fight that ensued cuts to the heart of society’s reappraisal of the inner lives of animals. — In the fall of 2016, Bradley Gerwig’s phone began to ring and ring. Morning, noon, and night, callers from around the world bombarded the 77-year-old’s landline at his modest ranch home in Keymar, Maryland, a blip of rolling farmland an hour northwest of Baltimore. Most callers were polite but firm…