Question: What nationality was the man for whose fiftieth birthday the book Minima Moralia was originally written for ?

Context paragraphs:
Minima Moralia: Minima Moralia: Reflections From Damaged Life (German: "Minima Moralia: Reflexionen aus dem beschädigten Leben" ) is a 1951 book by Theodor W. Adorno and a seminal text in Critical Theory.  Adorno started writing it during World War II, in 1944, while he lived as an exile in America, and completed it in 1949.  It was originally written for the fiftieth birthday of his friend and collaborator Max Horkheimer, who had co-authored the earlier book "Dialectic of Enlightenment" with Adorno.

List of Radical Thinkers releases: Radical Thinkers is a series of books released through Verso Books.  The series was first released in October 2005.  The series shifted towards themes in set 9 and began to release more frequently with fewer titles in each set.  In 2010, "Minima Moralia", "For Marx", "Aesthetics and Politics", and "Culture and Materialism" were reprinted in hardback under the Radical Thinkers Classics designation as part of Verso's 40th anniversary celebration.

Chihei Hatakeyama: Chihei Hatakeyama (畠山地平 , Hatakeyama Chihei , born in 1978) is an electronic music artist from Tokyo, Japan.  He released his first full-length album, "Minima Moralia" on Kranky in 2006.  Hatakeyama's music is characteristically very slow, composed by repeatedly processing guitars, pianos, and vibraphones on a laptop.  The result is a mix of droning chords and sparse single instruments rising above the mix.  His music may be classified as either post-ambient experimental music or new-age music.  Chihei Hatakeyama has released over 19 albums as of 2013.

Stephen Fry: 50 Not Out: Stephen Fry: 50 Not Out was a one-off, one-hour documentary/biography about Stephen Fry released in 2007 by the BBC, celebrating Stephen Fry's fiftieth birthday.

Torkel Franzén: Torkel Franzén (1 April 1950 – 19 April 2006) was a Swedish academic.  He worked at the Department of Computer Science and Electrical Engineering at Luleå University of Technology, Sweden, in the fields of mathematical logic and computer science.  He was known for his work on Gödel's incompleteness theorems and for his contributions to Usenet.  He was active in the online science fiction fan community, and even issued his own electronic fanzine "Frotz" on his fiftieth birthday.  He died of bone cancer at age 56.

Max Horkheimer: Max Horkheimer (February 14, 1895 – July 7, 1973) was a German philosopher and sociologist who was famous for his work in critical theory as a member of the 'Frankfurt School' of social research.  Horkheimer addressed authoritarianism, militarism, economic disruption, environmental crisis, and the poverty of mass culture using the philosophy of history as a framework.  This became the foundation of critical theory.  His most important works include "Eclipse of Reason" (1947), "Between Philosophy and Social Science" (1930–1938) and, in collaboration with Theodor Adorno, "Dialectic of Enlightenment" (1947).  Through the Frankfurt School, Horkheimer planned, supported and made other significant works possible.

W. G. Grace's cricket career (1896 to 1899): Following his "Indian Summer" in 1895, W.G. Grace continued to play first-class cricket through his fiftieth birthday in 1898 and finally severed his connections with both Gloucestershire and England in 1899.

TV's 50 Greatest Stars: TV's 50 Greatest Stars was a one-off British television awards show which invited the viewing public to vote for their favourite on-screen stars from a list compiled by the broadcaster ITV.  Fifty actors, actresses, presenters and comedians, both alive and dead, were featured on the list, the number 50 being chosen to coincide with ITV's fiftieth birthday celebrations in September 2005 (though technically there were 55 individuals on the list due to partnerships like The Two Ronnies and Richard and Judy being counted as one entry).  The two-hour show, directed by Mark Robinson, was hosted by Coronation Street actor Bradley Walsh, who ran through the stars in reverse order – the order was determined by the public, who could vote, either online or in the "TV Times", for five (no more and no fewer) of their favourite celebrities.  Members of the public could also nominate other television celebrities who had not been included on the list.  Actor David Jason won with Morecambe and Wise and John Thaw coming in second and third place respectively; the majority of nominees were comedians, a fifth were deceased and men outnumbered women by almost five to one.  Walsh was quoted as saying "I'm delighted to be involved in this show.  It will be a great celebration of some of the most fantastic stars from the last 50 years.  It will be interesting to see who the viewers vote to come out on top."  The show was narrated by Mel Giedroyc.

A Pirate Looks at Fifty: A Pirate Looks at Fifty is the autobiography of the singer and songwriter Jimmy Buffett, revolving around the singer's fiftieth birthday.  The book was released on June 3, 1998.

Muffin Men: The Muffin Men are a British band, based in Liverpool, England, which primarily plays the music of Frank Zappa and his band, The Mothers of Invention.  The group formed in 1990 for a concert in honor of Zappa's fiftieth birthday.  They went on to perform his music as a tribute band, along with some of their own compositions, worldwide.  Until his death in 2008, the band often featured guest vocals and percussion by Jimmy Carl Black, former drummer and vocalist from Zappa's Mothers of Invention, with whom they also performed songs by Captain Beefheart.

Supporting paragraphs: Minima Moralia Max Horkheimer
Answer: German