Ms. Sommerfeld, a philosopher in her own right, was swept up in another countercultural movement: In the summer of 2015, as hundreds of thousands of refugees arrived in Germany, she discovered the “New Right,” the intellectual spearhead of a nationalist movement that considers Islam and globalization existential threats.Her husband had celebrated the arrival of the refugees: “I think it is the first time in our cultural history that we have welcomed the foreign in this way,” he said.Ms. Sommerfeld, though, felt “anxious” and “repelled.”Today, she hopes her own fringe movement is tapping into a shifting zeitgeist that will reverberate in Germany and beyond, just as her husband’s did in its day.“We are the megaphone of a silent majority,” she claims.Mr. Lethen dismisses the analogy.“We were moved by a yearning for the world, we looked to the future,” he said. “They are moved by the yearning to go back to the womb of Teutonic tradition. It is a nostalgia for a past that never was.”