Obituary: Peter Rosenthal, 82, a Toronto professor and lawyer who saw the beauty in both exploring mathematics and representing social-justice activists

Peter Rosenthal

Peter Rosenthal, a mathematics professor who embraced social justice and became a lawyer representing a who’s who of left-wing activists in Canada during his career, died in Toronto on May 25. He was 82.

He was a proud Marxist and described himself as a “red diaper baby” whose activism was inspired by his mother Esther and whose love of mathematics came from his father, Harold. 

“Peter was a lawyer and a mathematician. He was also a radical, willing to challenge power whenever he felt people were being treated unjustly. After he went to law school, I asked him if he was going to quit his teaching position. ‘No’, he responded. ‘Math is beautiful,’” University of Toronto professor and friend Martin Klein told The CJN.

Law school graduation, 1990.

Rosenthal was born in Flushing, New York to Harold and Esther Rosenthal in 1941. His father was a high school math teacher, and his mother was a statistician and a left-wing radical. His maternal grandmother, Sonia, arrived in New York after participating in the failed 1905 Russian revolution and brought her commitment to the Bolsheviks with her.

Peter remembered his family mourning the 1953 execution of Julius and Ethel Rosenberg, who were accused of being Russian spies, as if they were personal friends. “I was 12 and I remember identifying with their kids and thinking how I’d feel if my own parents were executed,” he said in a 2008 interview.

He took part in the lunch counter sit-ins during the 1960s, picketing the local Woolworth to support integration. When suspected communists were outed during the McCarthy era his parents supported the individuals who were prosecuted and persecuted—particularly teachers. 

Following high school, Rosenthal attended Queens College and after a rocky start earned two scholarships at graduation. He accepted a four-year National Science Foundation Graduate Fellowship, married his high school sweetheart and first wife Helen Black, and relocated to the University of Michigan where he received his master’s and doctoral degrees and had his first child, Alan. His expertise was the abstract field of operators on Hilbert space. 

In 1967, he moved to Toronto where he accepted a position as a professor in the University of Toronto department of mathematics. Sons Jeffrey and Michael were born in Canada.  

In 1969 with the United States in the midst of the Vietnam War, Rosenthal joined a protest outside the U.S. Consulate in Toronto. While he was at the podium speaking against the war, the riot squad showed up. He was charged with causing a disturbance and obstructing police. “Having a criminal record would be a drag,” he realized and decided to fight the charges.

He hired a lawyer but also began reading up on the law and asking questions.  Eventually his lawyer asked during a recess if he preferred to present his own case.  He fired the lawyer, was acquitted on one charge, convicted on the other but appealed and won. 

His success with his own case spurred him on to represent 26 other protesters as a paralegal and eventually he took on cases of minor criminal offences and civil disobedience during the 1970s and ‘80s. But as a paralegal he was unable to appeal cases and was threatened by the Law Society of Upper Canada for practicing law without a license.

He hired lawyer Charles Roach to represent him. The law society abandoned its action and Roach encouraged Rosenthal to consider going to law school. In 1988, at age 47, while still working as a mathematics professor, he was accepted to University of Toronto’s law school and was called to the Ontario Bar in 1992.

“Like Peter, I worked in the late 1970s with Charles Roach, who was my political mentor. Unlike me, Peter did not need a political mentor—he and Charles were naturals. Peter worked at everything through a humanist lens and never faltered in his convictions,” lawyer and social justice activist James Lockyer told The CJN.

Rosenthal represented a “who’s who” of activists who were charged following political protests:

  • Shawn Brant, an Indigenous activist who participated in protests at Ipperwash and Oka and organized a 30-hour blockade of the CN line in Eastern Ontario in 2007.
  • John Clarke, a British anti-poverty organizer with the Ontario Coalition Against Poverty for 28 years.
  • Vicki Monague, an Indigenous activist who lobbied Simcoe County, near Barrie, Ont. to stop a dump—Site 41—from being built near Indigenous land.
  • Dudley Laws, a critic of the Toronto Police, who levelled allegations of racist practices against the police. 

His clients also included Toronto’s ‘squeegee kids’ and G20 protesters. He also represented the siblings of Dudley George, an Indigenous man who was fatally shot during a protest at Ipperwash, Ont.

Rosenthal’s highest profile case, in 2006, involved removing a clause from the Canada Elections Act that denied federal funding to any political party that received less than two percent of the national vote or less than five per cent of the vote in ridings where they ran candidates.

Rosenthal had six clients—the Communist Party of Canada, the Progressive Canadian Party, the Canadian Action Party, the Green Party, the Marijuana Party, and the Christian Heritage Party. He represented Miguel Figueroa, then the leader of the Communist Party. His victory at the Supreme Court of Canada changed election rules and ushered in a new era for fringe political parties.

“The Figueroa case is widely recognized as an important win for electoral democracy in Canada. We will always remember Peter for his unwavering commitment to win this 10-year battle, which we won in every court and which the federal government appealed at every juncture,” Elizabeth Rowley, president of the Communist Party of Canada commented in a tribute to Rosenthal.

Many in Rosenthal’s circle of friends became connected through an informal “Mishpocha Group” started by Congregation Darchei Noam in Toronto. Although Martin Klein knew Rosenthal professionally, they remained connected through the group for many years.

Another ‘Mishpocha Group’ friend, Marianne Levinsky told The CJN, “Peter was amazingly humble given his accomplishments. He was never boastful about what he’d done and if he spoke about it, it was to share amusing stories. He was always interested in what I was doing which surprised me, considering how interesting his life was.”

Michael Kerman met Rosenthal when their sons were playing baseball at Christie Pits. “We were both New York Jews. Jewish food and Jewish culture were part of him—he made great blintzes! The thing about Peter was he thought well of everyone—even if they were on the other side in a court case. He would tell me about cases involving people who were obviously up to no good and add, ‘They were very nice—they had good qualities.’”

Michael’s son is Max Kerman, the frontman of Canadian rock band Arkells, who released “A Little Rain (A Song for Pete)” in 2016, inspired by Rosenthal:

Rosenthal is survived by his wife Dr. Carol Kitai, his children Alan, Jeffrey, Michael, Daniel and Esther, grandchildren and a great-grandchild.