The only German philosophy professor who actively resisted the Nazis is nowadays virtually unknown. Though one or two scholarly monographs have appeared on him, Kurt Huber will not be found on any university syllabus. The silence that has swallowed his name and his works is almost as complete as that which followed when, after being stripped of his university post and doctoral degree by a Nazi People's Court, he was executed by guillotine in July 1943 for writing a pamphlet against National Socialism as a member of the White Rose resistance group.
A conservative Catholic who produced a classic study of Leibniz and made important contributions to aesthetics and musicology, Huber is today not much more than a footnote in history. When Yvonne Sherratt writes, "Huber's intellectual prowess remains as quiet in the Western world as it was under Hitler", she hardly exaggerates.
In contrast, some active collaborators with the Nazis feature among the most celebrated names of post-war philosophy. Serving the Nazis for a time as a university rector, Martin Heidegger cut off relations with Edmund Husserl, the Jewish philosopher who had secured his professorship, removing the dedication to Husserl from Being and Time (Heidegger's principal work) and failing either to visit his mentor when he was dying or attend his funeral in 1938. As a result of the intellectual campaign waged by his former student and lover Hannah Arendt, and support form prominent figures such as Jean-Paul Sartre, Heidegger succeeded in becoming one of the most influential of late 20th-century philosophers.
The jurist Carl Schmitt, who rose to become Hitler's chief legal advisor, was arrested by American forces in 1945. Yet he avoided any public trial and returned to his home town where he received distinguished visitors such as the French Stalinist and Hegel scholar Alexandre Kojève. By the time Schmitt died in 1985 at the age of 97, his books had been translated and published throughout the world.
Sherratt describes Hitler's Philosophers as being concerned with "a terrible secret: the story of how philosophy was implicated in genocide". It is a good description of a fascinating, disturbing and necessary book. No doubt the collaboration of German philosophers with the Nazi regime was largely opportunistic. When there is fear in the air, philosophers are no more inclined to heroism than doctors or teachers, who also collaborated with Nazism on a large scale.
But in some ways, philosophy itself had opened the way to the Nazis. As Sherratt notes, it was Immanuel Kant who wrote that "the Jewish religion is not really a religion at all" and described Jews as "a nation of cheats". As she comments, "the greatest thinker of the Enlightenment... provided a legitimate basis deep within European culture for the potential criminalisation of the Jews". She might also have mentioned that Voltaire – the other great Enlighten- ment worthy – promoted a version of the pre-Adamite theory of human origins in which Jews were remnants of a pre-human species.
By revealing the sources of Nazi ideology in German philosophy, Sherratt nails the myth that Nazism was an inexplicable aberration in European history. In the absence of the chaos that followed the First World War, Hitler's movement would not have gained the mass support it did. But the ideas he deployed when in power were widely current in fin-de-siècle Europe, not least in progressive circles.
An important feature of Nazi ideology, commonly neglected by those who see Nazism as simply a variety of irrationalism, is that Nazi racism claimed to be based in science. One the books admired by Hitler in his early years was Racial Typology of the German People by Hans FK Gunther, one of many exponents of "scientific racism". Among these, none was more important than Ernst Haeckel (1834-1919), who used a distorted version of Darwin's ideas to advocate the use of eugenics. Citing a recent assessment, Sherratt rightly maintains that "Haeckel and his fellow Social Darwinists advanced ideas that were to become the core assumptions of National Socialism".
But similar ideas were widespread in many European countries. In Britain, where they originated in the work of Francis Galton, eugenicist theories continued to be influential until after the Second World War. It was only the destruction of the Nazi regime and the ensuing publicity given to its crimes that relegated these ideas to the margins.
In detailing the complicity of philosophers with Nazism, Sherratt is not opening up new ground. There is a large literature on Heidegger's involvement, while scholars such as Richard Wolin have explored the appeal of fascism to several generations of European intellectuals. There are no startling insights here into why some of Germany's leading philosophers actively collaborated with Nazism. From one point of view, Heidegger's flirtation with Nazism may have been not much more than an extreme example of careerism; but it may also have flowed from some deep features of his philosophy. Dealing mainly with events and personalities rather than the internal logic of philosophical positions, Sherratt cannot tell us whether it was the philosopher or the philosophy that was principally at fault.
Sherratt's focus on people may be a weakness, but it is also one of the book's strengths. The stories she presents of the philosophers who fled Germany – Walter Benjamin, Theodore Adorno and Hannah Arendt – are rich and moving, sometimes amusing and at times unexpected. I hadn't heard of Adorno's encounter, while exiled in California, with Greta Garbo and her dogs. Again, I wasn't aware that Carl Schmitt was singled out by Vera Lynn for his endorsement of violence. It's instructive and somehow uplifting to know that a wartime singer showed herself to be more clear-eyed and intelligent than a gaggle of philosophers.
John Gray's latest book is 'The Silence of Animals: on progress and other modern myths' (Allen Lane). He will appear at the 'Independent' Bath Literature Festival on 10 March