She and a colleague, Dr. Thomas Bock, were influential in Germany and beyond for popularizing, in 1989, a three-way discourse during which patients, their relatives and their doctors were heard equally in what they described as a “trialogue.”

Her agenda for those talks seemed elemental: Mental health professionals need to treat their psychotic patients as people with individual problems that can be freely discussed, not as soulless objects of study. And people with psychoses should try to make sense of their symptoms by questioning their doctors and themselves.

“I think if I had depression, I could imagine taking a medication,” Mrs. Buck said in a 2005 interview. “But in a psychosis, I have to be asked what the psychosis means. If it is important to a human being, it must not be suppressed by medication; there must be talks.”

Or as she famously put it, “As long as we talk to each other, we don’t kill each other.”

Dorothea Sophie Buck-Zerchin was born on April 5, 1917, in Naumburg, near Leipzig, in eastern Germany. She was raised in Oldenburg, near Bremen in the north, and then in a parsonage on Wangerooge, an island in the North Sea, where her father, Hermann, was a pastor. Her mother was Anna (Lahusen) Buck.

By concealing both her psychiatric history and her forced sterilization, Mrs. Buck was able to enroll in 1942 in a private art school in Frankfurt, where she learned pottery. She worked as a sculptor and taught art from 1969 to 1982 before being overcome by the lingering revelations of mass murder of mental patients by the Nazis, and by what she found to be continuing mishandling of the mentally ill in modern-day Germany.

“These hidden medical crimes and the unchanged degrading and inhuman German asylums disturbed me deeply, although I could have used my concentration for my artistic work,” she wrote on her website. “As a sculptor, I lived on public commissions in Hamburg, which could only be gained through competition. When, in 1965, my last bronze objects were placed, I stopped this work. As long as there was no elementary humanity, art seemed less important.”

Mrs. Buck wrote a play about the Nazi-era murders of the mentally ill and the disabled, published essays opposing medical research on patients who lack the cognitive ability to grant consent, and gave lectures to promote more humane psychiatry.