Hans-Jürgen Krahl (17 January 1943 – 13 February 1970) was a West German philosophy student and political activist who came to wider prominence as a participant in the '68 Student Protest movement of which, in the eyes of admirers, he was a leading ideologue.

He was a leading member of the fractious Socialist German Students' League. During the mid-1960s, Krahl became a star student and doctoral pupil of the polymath-philosopher Theodor W. Adorno. Early in 1969, after four years during which Krahl treated Adorno as an academic mentor, there was a falling out between the two men, however. This arose in the context of a student occupation of the University of Frankfurt Institute for Social Research in which Krahl was involved. Adorno, as director of the institute, summoned the police to evict the "trespassing" students on 7 January 1969. Adorno died suddenly later that same year, eleven days after the end of the trial process that followed on from the events at the institute.

Krahl himself was only 27 when he was killed, a front-seat passenger in a motor accident on an icy road north of Marburg, barely six months after the death of Adorno. His reputation as the great theoretician of Europe's '68 movement, able and willing to grapple with both the ideological and the economic mechanisms of mature capitalism, persists among scholars of the political left. Much of Krahl's written work, which included large amounts of material delivered orally – albeit in perfectly formed prose structures – and recorded at the time, to be transcribed onto paper only much later, was published posthumously.

Life Provenance and early years Hans-Jürgen Krahl came from a lower-middle class ("kleinbürgerlich" / "petit bourgeois") background in what he later termed "the darkest recesses of Lower Saxony" (aus "den finstersten Teilen Niedersachsens"). He was born in January 1943 at a time when suspicions were stirring among the German people that the Second World War might not end in the promised German victory. Rudolf Krahl, his father, and his mother, born Erna Schulze, were both employed in private sector business. Rudolf Krahl was no fan of the National Socialists during the Hitler years, but nor is there any indication that he engaged actively in political resistance. Where it came to upbringing, Krahl's parents appear to have provided their child with an upbringing marginally more liberal than would have been deemed conventional at the time. Hans-Jürgen was still very small when, probably early in 1944, he lost his right eye during the course of an aerial bomb attack. For the rest of his life he wore an artificial eye. By the time the European war ended in May 1945 the little family had moved to Stettin, but early in 1945 they had joined the flood of refugees desperate to escape from the advancing Soviet army, and ended up back in Sarstedt, the little town a short distance up-river of Hannover. It was in Sarstedt that he spent most of his childhood. When he was 15 the family relocated to Alsfeld, some 100 kilometers further to the south. After he grew up he would look back on both the towns in which he spent his childhood as archetypal examples of conservative "small-town Germany".

According to his own later reports, as a boy Krahl became involved with the "Ludendorffbund", a right-wing extremist political organisation under the leadership (at least till it was outlawed in 1961) of Mathilde Ludendorff, widow of the infamous General Ludendorff 1865-1937. The "Ludendorffbund" was a populist movement dedicated to ethniocationalism and racism and other mystical extremist notions which had fallen out of fashion in western Europe in the aftermath of the twelve year Hitler nightmare, and was in its day regarded as somewhat "niche". By contrast, the CDU (political party), the centre-right party of Konrad Adenauer, of which Krahl became a member in 1961, was widely perceived as the heart of the political mainstream, particularly in the conservatively inclined small town German towns in which Krahl grew up. Nevertheless, as his political journey across the political spectrum continued through the 1960s, Krahl would come to view the CDU, with which he had engaged as an activist member between 1961 and 1963, with much the same level of contempt and distaste that he would epply to the "crypto-nazi" "Ludendorffbund". Meanwhile, he was still living in Alsfeld with his family when he became a "passionate founding member" of an Alsfeld branch of the "Junge Union", the youth wing of the CDU.

University student In 1963 Krahl enrolled at the University of Göttingen to study Philosophy, Germanistics, Mathematics and History. At the same time he joined the Coburger Convent Verdensia student fraternity.Matthias Micus: Hans-Jürgen Krahl. Der vagabundierende Revolutionär. In: Stine Marg, Franz Walter (Hg.): Göttinger Köpfe und ihr Wirken in die Welt. Vandenhoeck & Ruprecht, Göttingen 2012, ISBN 978-3-525-30036-7, pp. 227–237, here p. 230.

By 1964 Krahl had left the CDU Alsfeld party branch. According to Krahl himself, he was expelled from it during an angry disagreement. In 1964 he joined the "Sozialistischer Deutscher Studentenbund" ("Socialist German Students' League" / SDS), an increasinggly radical political organisation, members of which had been expelled from West Germany's centre-left Social Democratic Party (of which it had originally been a part) in 1961, due to disagreements over German re-armament. Rudi Dutschke would join the SDS in 1965, after which the two men successfully led the organisation further away from the traditional political mainstream. By the later 1960s Krahl was widely recognised as one of the SDS's leading exponents of anti-authoritatian socialism.

Theodor W. Adorno and the "Frankfurt School" In 1964 or 1965 (sources differ) Krahl switched to the so-called Frankfurt School of the "Institut für Sozialforschung" (IfS / "Institute for Social Research") which at that time was still a stand-alone institution (though it has subsequently been reincorporated into the Goethe University in Frankfurt). The lure was the opportunity to study with Theodor W. Adorno, who would have a decisive and lasting influence on him.

In 1965 he began work on his doctoral dissertation on the "Natural Law of the Capitalist Movement applying the definitions derived by Karl Marx" ("Naturgesetz der kapitalistischen Bewegung bei Marx"). The doctorate was supervised by Adorno himself. Sources identify Krahl as "Adorno's favourite student", recalling that Krahl was the only one of Adorno's students or staff members at the IFS whom Adorno was prepared to debate on a basis of intellectual equality. It is said that Krahl was blessed with an excellent memory and power of recall and that he was exceptionally lucid. In terms of socialist political philosophy, he had found the time and opportunity to become well-read in the subject. He was also hugely respectful of his doctoral mentor-supervisor, from whom he drew numerous key concepts of the "Frankfurt School critical theory", which he applied in a number of philosophical-political writings of his own.

Krahl's break with his philosophical father figure came after four years. A student occupation took place at the IFS on 7 January 1969 which Adorno and his senior colleagues at the institute invited police to evict. In Frankfurt the public mood in respect of student protests had been somewhat heated for more than half a year, and the police unhesitatingly complied with the request of the Institute authorities. Following the eviction, police arrested 76 of the students involved, including Krahl, the favourite pupil whom by many criteria Adorno had at this point vehemently disowned.

Adorno was painfully conscious of the brutal irony whereby "a piece of political theater" had left him identified by many of his students as a defender of conservative repression. He attempted to resume lecturing in June 1969, but active hostility from students who favoured “extra-parliamentary opposition” and who might previously idolised him prevented it. A few weeks later, on 18 July 1969, he found himself invited to testify at Krahl's trial on a charge of breaching the peace. If, as some commentators seem to have anticipated, Krahl was hoping to be able to recreate the Athenian Agora in a Frankfurt court room in order to engage in a very public debate on the fundamentals of critical theory with its most important theoretician, he was disappointed. It is hard to be confident that Adorno was unaffected by the months of ad hominem attacks from IFS radical students who identified a polarised battle between himself and his (formerly) favourite pupil, however. The trial that followed may have been the last straw. A few weeks later, he took a break with his wife, visiting Zermatt where, in defiance of medical advice, he took a hike into the mountains and suffered a heart attack. He died in a Swiss hospital on 6 August 1969. Krahl's own death followed only six months later.

Sigrid Rüger and the "tomatoes incident" On 13 September 1968, Krahl was involved, unintentionally, in an incident at the 23rd delegates' conference of the SDS which some have characterised as the launching pad for second-wave feminism in West Germany. The conference was held at Frankfurt am Main, which was Krahl's home city and, importantly, home to a number of nationally distributed West German and international newspapers along with many of their journalists. As a leading member of the SDS, Krahl was one of those seated in a single row along the front of the stage, facing the main body of the hall. In the main hall, on one side of the room, was grouped a small party of women from the Action Council for women's liberation. Unbeknownst to the conference organisers, the women were on a mission of their own. Not all of them were SDS members. One who was a relatively prominent member within the SDS was Sigrid Rüger, heavily pregnant and highly visible, in addition, on account of her very red hair. Something these women shared was a belief that among the SDS (male) student leaders, there was a singular absence of empathy with feminist viewpoints and issues.Vorwort zur Neuauflage von Ute Kätzel. In: Ute Kätzel (Hrsg.): Die 68erinnen. Porträt einer rebellischen Frauengeneration. Ulrike Helmer Verlag, Königstein/Taunus 2008, . p. I.

Another of the women in the group was Helke Sander an activist film-maker originally from Berlin who had recently returned to Germany after several years living and working in Helsinki. Sander stood up and, taking the organisers by surprise, delivered a speech. There seems to have been some frantic sotto-voce discussion among the SDS leaders seated on the stage over how to shut this woman up; but in the event most delegates listened in relative silence. It was quite a short speech, but nevertheless managed to tackle in some depth several of the priorities of the feminists' Action Council. It concluded with a rousing plea: