In the late winter of 1980 I was sixteen years old and had a habit of wandering the Art Institute of Chicago, looking for dead friends and teachers. I had read my mother’s college art history textbooks; I thought I understood the basic idea, which was progress; each generation of artists improved upon and contradicted the artists that had come before them. But as I roved through the dim galleries of Impressionist masterpieces I didn’t feel capable of joining that conversation, which was over long ago. The contemporary galleries full of Minimalism and Conceptual art did not speak to me. Medieval altarpieces fascinated me but the religious impulse that inspired them did not.