Ardor, inspiration, the soul, the sublime: Such terms have long since fallen from favor among critics and artists alike. In his new collection of essays, Adam Zagajewski continues his efforts to reclaim for art not just the terms but the scanted spiritual dimension of modern human existence that they stake out. Bringing gravity and grace to his meditations on art, society, and history, Zagajewski wears his erudition lightly, with a disarming blend...