Gian Lorenzo Bernini, Model for the Lion on the Four Rivers Fountain (Ca. 1649–50), Accademia Nazionale di San Luca, Rome Photo by Zeno Colantoni, Rome; image courtesy of the Metropolitan Museum of Art.

For admirers of Gian Lorenzo Bernini (1598–1680), or even of sculpture generally, the collection of fifteen of his terracotta sketches in the Fogg Art Museum has long been a pilgrimage point to glean a deeper insight into his genius, or simply a straightforward Bernini fix. If the essence of his marbles is their jaw-dropping illusionism—their ability to simulate wind-blown hair, soft flesh, even tears—what distinguishes these preparatory works is their immedi ...