The letter offers the so-called Nietzschean perspectivism as a pretext or guidance for Benn’s literary behavior under the Nazis. In the quotation he explains how absurd medical theories (precisely those favored by the Nazis) can be made into poetical material and become a vehicle of poetic expressivity regardless of their actual content, or of the poet’s actual attitude toward them.
For the German speakers, here is the full quotation:

It is clear that this attitude applies to all Benn’s essays of the Nazi time—writings highly artistic and sophisticated in form but odorous with Nazi ideology. Basically, Benn wants to fool the Nazis into accepting his avant-garde (and thus ‘degenerate’) poetic experimentation by playing with their ideologically charged vocabulary, such as race, folk, nation etc. instead of his previously favored material, e.g. the exotic sounding names of Mediterranean flora and fauna. He wants to secure his freedom and safety to play by changing the game pieces but not the rules of the game itself.

Nowhere else in Benn’s writings I have seen such an open confession as to what this business of his Nazi interlude was about. Ironically, it reminded me (who grew up under the rule of totalitarianism) of my own sport and experimentation with the vocab of the dying Soviet ideology in high school.

Each chapter of our history books, beginning with the Babylonian and ancient Egyptian civilizations and ending with the latest congress of the Communist Party of the Soviet Union, ended with a coda entitled – “Leading Role of the Masses in the Class Struggle in Babylonian Society,” “Leading Role of the Masses in the Class Struggle in Ancient Egyptian Society,” “Leading Role of the Masses in Early Medieval Europe” etc., etc., until it changed into the leading role of the proletariat in the diverse societies of the 19th century and the leading role of the communist party in the 20th. The content of these concluding paragraphs was always the same, formulaic and predictable, and one did not need to prepare or know anything about Ancient Egypt or Medieval Europe to get the best grade on this part of the chapter.

I used to entertain my classmates by raising my hand to answer this particular part of the lesson. The goal was to juggle the vocab pertaining to this or that culture, in a display of rhetoric, where the manipulation of certain formulas and ideological slogans could have an air of an argument while being utterly without content. I usually drove myself into a condition of exaltation by rhetorical improvisation, which entertained my fellow students who even put aside their routine occupations during the history lesson to listen to my performance.

The riskiest performances were those where I did not have a clue about any other material in the chapter with the exception of the “leading role.” And the greatest pleasure was the confusion of the teacher who did not have the guts to shut me down, since I could always justify my fervor politically and ideologically as an ecstasy about the actual “leading role” instead of the ecstasy of the rhetorical game. In the end, the teacher learned not to ask me about the “leading role,” and for me, answering questions about the content-oriented parts of the lessons was no fun. The whole excitement stemmed from the ideological predictability of the “leading role”; the rhetorical exhibitionism was all the more exciting for being predicated on a lack of content.

Such were the small pleasures and joys that totalitarianism allowed us in its decadent phases. I could immediately relate to what Benn was talking about in his unguarded moment of writing to his friend. The only difference between his “aesthetic” as he envisioned it under the Nazis and my school game was that his “game” lacked any element of irony and parody. He chose to intoxicate himself on the Nazi vocab like an alcoholic who is forced by circumstances to change from drinking cognac to drinking cheap eau de cologne.

In academic research on Benn one still finds scholars who take his attitude and his “perspective” theory seriously. I think this is absurd. Actually, it had nothing to do with the intellectual ideas of this period but just with the psychology of everyday life.
Benn’s acceptance of the regime was protective coloration. Its cause was fear. Benn hoped to spare himself the fate and misery of the writers who had already left Germany for France, England, or the USA; he wanted to save his literary and medical career, to stay in the familiar linguistic surroundings of home. On February 27, 1933, Benn wrote Egmont Seyerlen in a state of enthusiasm:

At this time Benn still felt personally unaffected by these persecutions (his books had not yet been declared “suspect”). Nor had he yet been removed from the list of certified physicians of the National Socialist Medical League. That would change soon. In fact, as early as 1934 Benn would strive frantically to silence rumors of his Jewish ancestry by seeking to document his Aryan descent.

Benn’s protective experiment failed. His art of intoxication with choice phrases such as the “loins of the race,” “Volk,” “Grund und Boden” did not go beyond being a piece of propaganda and his “aesthetic” stayed what it was – an act of political mimicry. What made the experimentation fail is the fact that the signifiers on which his rhetoric hinged, unlike the names of the Mediterranean plants, had a political reality behind them, a reality which could not be easily put aside. Instead of being a means of estrangement (as was the case with the esoteric and exotic signifiers of his early prose and lyric), his play with the Nazi vocab harmonized with an affirmation of Nazi politics.

What happened was the opposite of what Benn had planned - an instrumentalization of aesthetic expression in favor of ideological articulation, the metamorphosis of artistic disinterestedness into ideological purposefulness. Thus, he just offered a case in point for Horkheimer’s and Adorno’s later observations on the paranoid sensibility of fascism in Dialectics of Enlightenment. When, for example, in his 1933 letter addressed to the exiled German writers who had called on him to disavow the Nazi regime, Benn accuses the emigrants of desiring defeat for the German state and folk, and paints a threatening picture of Germany encircled by French colonial Negro troops, it is difficult not to recall Adorno and Horkheimer’s words about the typical rhetoric of the Nazis:

Alas, Benn got caught up in his own game, or as a German saying goes: Aus Spass wurde Ernst. Ernst is by now 77 years old and counting.