Peter Rosenthal has been Professor of Mathematics at the University of Toronto since 1967. His interest in law stems from his interest in social justice. He’d had a long career as a paralegal representing protesters charged with summary conviction offences, people before administrative tribunals, including workers fighting denials of compensation, and a lawyer in a disciplinary hearing before the Law Society of Upper Canada. He subsequently attended law school, graduated from the University of Toronto in 1990, and was called to the bar in 1992. He has since represented protesters, including members of the Black Action Defence Committee, of the Ontario Coalition Against Poverty, and G20 activists. He’s conducted criminal, civil and constitutional litigation at all levels of courts, and acted at many coroner's inquests. He still teaches mathematics at the University of Toronto and researches in mathematics. He’s also Adjunct Professor of Law, teaching "Litigation and Social Change."