Born in Magdeburg, then part of the Prussian Province of Saxony, Hirsch earned his Abitur in Halle. He studied law and political sciences at the University of Marburg. He completed his first and second Staatsexamen in 1954 and 1959, respectively, and earned his Doctor of Laws in 1961 with a doctoral thesisDer Begriff des Bundesstaates in der deutschen Staatsrechtslehre. He worked as a lawyer at the Amts- und Landgericht Düsseldorf from 1964. He was a member of the Wirtschaftsvereinigung Eisen- und Stahlindustrie from 1960 to 1967.
Political career
Hirsch joined the FDP in 1949 and was a member of their youth organisationJungdemokraten until 1964. He served on the city council of Düsseldorf from 1964 to 1972 and was president of the regional party from 1971 to 1977. He served on the party's board in North Rhine-Westphalia from 1971 to 2005, and then became its honorary chairman. He first attained a seat in the Bundestag in the 1972 federal election. Within the party, which served in a coalition under chancellor Willy Brandt, he belonged to the so-called "Mitteldeutsche Fraktion" around Hans-Dietrich Genscher and Gerhart Baum, who supported Brandt's Ostpolitik. From 1973 to 2005, he was on the FDP's national board and then became an honorary member. Hirsch left the Bundestag in 1975 to become Minister of the Interior of North Rhine-Westphalia, serving as vice minister-president from 1979. He returned to the Bundestag in 1980. From 1994 to 1998, he was a vice president of the Bundestag. Hirsch gained a reputation as one of the most vocal advocates for civil liberties in Germany, which earned him the in 1998 and the Fritz Bauer Prize in 2006. Hirsch was also awarded an honorary doctorate by the Goethe University Frankfurt in 2006, and was praised in a speech by as "a nonpartisan, relentless, and aggressive advocate of the rigorous rule of law".
Hirsch was president of the council of the Hochschule Düsseldorf from 2008 to 2015, with a short interruption. For his influential work for the academy, he was the first to be awarded an honorary citizenship, in May 2016. He died on 11 March 2020. The Hochschule wrote in an obituary: