that principle has certainly been abused recently by many of the Wokerati. But the author is not talking about censoring ideas expressed in the public sphere. He is talking about selecting what to teach in his classroom. He is going to teach them that Nazism is both mistaken and evil, and explain why, rather than present Mein Kampf and the declaration of independence side-by-side for equal consideration. at the same time, he’s also going to enable them to empathize with how people got seduced by Nazism. As a critical thinking teacher myself, I find that impressive.