There are many questions to be asked about the Metropolitan Museum of Art's decision to dedicate its spring Costume Institute exhibition to the designer John Galliano, and then to cancel it when the backlash came. Did organizers, including the Met trustee Anna Wintour and the Costume Institute curator Andrew Bolton, think that, after a stint in rehab and a multitude of apologies, the past had been forgiven — or perhaps even forgotten? I understand the outrage and the objections over "John Galliano: Horizons." But the exhibition should not have been canceled. Instead, the Met Gala should have been canceled.

In 2011, a French tribunal found Mr. Galliano guilty of making hateful remarks about Jews and Asians. His antisemitic comments were vicious and bigoted, and were not a one-off incident. Mr. Galliano was fired from Dior. He tried to make amends by studying the Holocaust and antisemitism. Ms. Wintour stood by him. Three years after his professional conflagration, Mr. Galliano was hired as creative director for Maison Margiela. Now he works with Zara.

This is a worthy subject for an exhibition. I wanted Mr. Bolton to mount a show that would examine Mr. Galliano's profound failings closely and without hesitation — not as unfortunate asides to his career but as something central to it. "I believe deeply in the responsibility of museums to examine difficult histories with rigor, candor and care," Mr. Bolton said. Trying to understand Mr. Galliano could help us make sense of other contradictions in character, of how hate hides in shadows.