Yesterday we saw how Martin Heidegger (1889-1976), considered by many to be the most distinguished philosopher of the twentieth century, was also a devout Nazi and anti-Semite.

What happened to him after the war? Well, while other high-profile Nazis were put on trial or at least enrolled in denazification programs, he was forbidden from teaching but otherwise left alone. Fortunately for him, he had a number of prominent friends and admirers (among them Jean-Paul Sartre) who were eager to help in his postwar rehabilitation. His most fervent champion was Hannah Arendt, his former student and lover, whose 1951 book The Origins of Totalitarianism made her a big name and gave her a great deal of influence in intellectual circles on both sides of the Atlantic. Arendt, who had fled Europe for America in 1941, was herself Jewish, but Heidegger’s longtime, outspoken anti-Semitism didn’t keep her from doing everything she could to try to rescue her mentor’s reputation and to try to make everybody else believe that he hadn’t really been as devout a Nazi as he actually was.

She promoted him tirelessly, and as late as 1971 was still trying to get him off the hook by comparing him to Thales, an ancient Greek philosopher who became “so absorbed in the heavens that he stumbled into the well at his feet.” (One point: isn’t it curious for a Jewish woman to describe a Hitler-besotted man as “absorbed in the heavens”? Another point: isn’t it pretty obvious that a philosopher who’s “so absorbed in the heavens that he stumbled into the well at his feet” is absolutely useless as a guide to life, which is supposed to be the whole point of philosophy?)

For his part, Heidegger, after the war, guilefully spun his sincere devotion to the Third Reich as, alternatively, (a) a charade he’d pulled off solely to save his own skin or (b) a noble effort by a serious educator to protect German education from pollution by Nazi thought.

Even after the war, however, Heidegger couldn’t entirely disguise his real sympathies. For example, he actually equated Nazi death camps with the “motorized food industry” – the idea being that both phenomena were deplorable instances of runaway technology. In a letter to a former student, he suggested that the student, who had apparently expressed outrage about Nazi genocide, should instead be angry about the Communist treatment of East Germans.

In any event, Heidegger never explicitly apologized for his own Nazism. Never.

Sartre and Arendt weren’t alone in striving to clear Heidegger’s name. He had innumerable apologists, and to read through their writings is to see the same arguments surfacing again and again. One: he was only a Nazi for a certain number of years, and then snapped out of it. Two: hey, a lot of Germans were Nazis – it was in the water back then. Three: he may have been a Nazi, but he was not as fanatical as many other Nazis, and in fact his intellectualism may well have helped take the edge off of Nazism in the minds of his students and others who came under his influence. Four: okay, he was a Nazi, but that fact doesn’t discredit his philosophy, because they’re too different, utterly disconnected things.

But none of these arguments will wash. Yes, he was an outspoken Nazi for only a few years in the 1930s, until he was removed from his post as university rector – but after that, he never openly opposed the regime, and in his private notebooks continued to express admiration for Hitler’s regime. Yes, a lot of Germans were Nazis – but nobody’s asking us to treat their philosophical reflections with respect. Yes, he might not have been as evil as Goebbels or Goering or Hitler himself, but what kind of standard is that to hold a philosopher up to?

As for the idea that Heidegger’s philosophy and his Nazism can be viewed as unrelated to each other – no, this won’t do. T.S. Eliot was an anti-Semite too, and his anti-Semitism crops up once or twice in his poetry. But it doesn’t completely cancel out the value of his work. Eliot was an artist. Heidegger was not. He was a systematic thinker, all of whose ideas were parts of a coherent whole. His philosophy, indeed, was all he had to offer, and his prose was nothing more or less than a sturdy vehicle by means of which he communicated it. And an inextricable element of Heidegger’s philosophy was his Nazism.

Many a professional philosopher, to be sure, has strenuously resisted this view. There is a tendency in the philosophical profession to act as if a philosopher’s real-life conduct, prejudices, and public statements do not necessary have anything to do with the value of his published philosophical works. They behave as if philosophy is all about abstractions on the page or in the classroom. On the contrary, philosophy is supposed to be a guide to living life, a set of prescriptions for how to conduct oneself in the company of one’s fellowman.

For years, Heidgegger’s defenders sought to preserve a firewall between his Nazism and his philosophy. Then, in 2014, came the publication of his so-called Black Notebooks, which contained expressions of Nazi enthusiasm and Jew-hatred more vehement than anything of his that had been previously published. The notebooks, which were widely discussed and reviewed, made it harder than ever for his admirers to dismiss or minimize his politics and prejudices. More on this tomorrow.