This failure dashed Heidegger's optimism that the National Socialist movement would catalyse his hoped-for "turn of the age". But it changed nothing about that hope itself, and in the following six years, during which he published nothing, he worked out his vision for German renewal. He eventually transformed it into a revolutionary account of the whole history of Western philosophy which — lifted from its nationalist soil — would make his name in the English-speaking world. The notebooks of the years 1935-41 are therefore a hugely exciting publication: a live record of Heidegger's famous ideas taking shape. But for the moment, any assessment of their significance for understanding the so-called "late Heidegger" is likely to be displaced by the tyranny of the urgent: his repeated mention of the "tenacious dexterity of calculation and banking and shuffling that constitutes the foundation of the Jews' worldlessness". These references are of urgent concern not so much as evidence of a privately-held anti-Semitism-which was too common in the history of the Christian West to be a reliable criterion for hindsight discrimination — but as threads in the cloth of his philosophical experiments. The notebooks of these years are no diary or chronicle: there are few dates and no direct references to current events. Heidegger's references to the Jews are not political asides, but part of his philosophical project.

In the middle years of the Nazi regime, Heidegger distilled his objections to the soulless efficiency of the party into a criticism of "technology", by which he meant not a branch of science or a type of equipment, but a way of engaging with the world: to think "technologically" is to see the world as nothing but a source of raw material to be sorted, tallied up and deployed at will. But this denial of one's own rootedness in a shared world cannot long go well: by the technocrats' own logic, they themselves are soon reduced to mere resources to be used up and disposed of.

Heidegger now directed the revolutionary vision that he had hoped to pursue within Nazism against this technological tyranny. Against Hitler's National Socialism, he pitched the romantic nationalism of Friedrich Hölderlin, who — following Fichte and Hegel — envisioned the Germans as a people called to school the world in a different attitude to the world: a poetic disposition of attentive letting-be that allowed the self to become a "clearing" on which the light of Being might fall and show forth beings as they are. In a gesture of indirect resistance, Heidegger lectured enthusiastically about this Hölderlinian nationalism in Freiburg.

At the same time, the heuristic of "technology" allowed Heidegger to escape the deadlock of competing nationalisms by exposing Nazism as not very special, but in fact quite similar to "Bolshevism" and what Heidegger called "Americanism": another machine for grinding down the rich inner life of the world into a mass of homogenous, useful material. More ironically, Nazism turned out to be itself an instance of the mentality that it projected on to the Jews: a deracinated "worldlessness" resulting from a "tenacious dexterity of calculation and banking and shuffling".