When the young Joseph Beuys laid eyes on an illustration by Wilhelm Lehmbruck, he was profoundly struck. “Everything is sculpture, this picture seemed to call out to me,” he said. Indeed, this epiphany was an important step toward Beuys’s development of Social Sculpture, a radical concept proposing that anything could be art and anyone could be an artist. In 1986, just a few days before his death, Beuys was awarded the Lehmbruck prize. In an unforgettable speech, he praised Lehmbruck as his mentor and his teacher. For the occasion of Beuys’s 100th birthday, this rare exhibition places the two men’s work side by side. —E.C.