Isabella Stewart Gardner’s museum endured for decades as a personal memorial, seemingly immutable, until it was transformed by a dramatic robbery, the decision to offer temporary exhibitions, and a bold addition. The exhibitions are often designed to enlighten one or more of the museum’s works, and this particular example set out to create a context for two of Mrs. Gardner’s masterpieces: a large painting of the sculptor Baccio Bandinelli flourishing a drawing, and the Pietà drawing Michelangelo created as a presentation gift to Vittoria Colonna.

The thorny question of how Italian Renaissance sculptors found drawing useful is explored in the catalogue’s essays and entries, which clarify what little we know about how these sculptors thought and worked. The fifteenth-century evidence for why sculptors drew is limited to a few examples of problematic attribution and uncertain connection to surviving works, while the more numerous sixteenth-century examples elucidate specific works or the practices of particular artists but reveal little about general procedures. The surviving examples are, we must presume, only a small percentage of the studies that played a role in the creative process during this period. Despite these limitations, the authors of the five essays and forty-seven catalogue entries establish a rich picture of the broadest issues and explore in impressive depth the problems raised by the works in the exhibition.

Take, for example, the question of the drawing from Rennes that has been attributed to Donatello and, because it represents a figure of David, has been related to the famous bronze in the Bargello. What role this drawing might have played in the trajectory of the David’s creation — from the germ of an idea, most probably inspired by a query or comment from a patron, through to the design, casting, polishing, and partial gilding of the finished figure — is worth examining. But while the entry discusses all the relevant issues — attribution, date, function, inscription, medium, relationship to the finished figure — in depth, even this thorough investigation fails to provide much enlightenment into the leaps of imagination that led to the final product; we want to know so much more. After pondering this drawing for more than forty years, I will admit that I now find the incisive, dramatic execution and the interpretation of both the David and the Massacre of the Innocents on the recto consistent with what I know about the artist. The innovations here seem consistent on every level with those we find in Donatello’s other works.

Michael Cole’s introductory essay boldly questions “Why Did Sculptors Draw?” In responding, he defines six possible areas of investigation based on motivation and function: installation, comparison, composition, vantage, documentation, and annotation. I would add presentation as a seventh to encompass drawings created as ends in themselves, including the Gardner’s Pietà for Vittoria Colonna. Cole’s categories promise to be useful, for by focusing on function they encourage us to look beyond individual works in an effort to expose connections among artists’ working methods.

The works in the Gardner show provided a helpful spectrum of both function and style. The highlights included six drawings and a related terra-cotta model by Michelangelo; nine drawings by Bandinelli that reinforce the arguments in Linda Wolk-Simon’s essay; Cellini’s marvelous drawing of a satyr and his less interesting bronze of the same subject; and no less than five designs for fountains, the last of which, by Bernini and his workshop, brought the exhibition into the seventeenth century. Was fountain design so new that it required more drawings than other types of commissions? Did patrons for fountains demand additional clarification before proceeding? Or are these merely accidental survivors?

The Gardner’s staff deserves our thanks and congratulations for the manner in which their exhibitions continue to enrich the cultural scene in Boston. While the art historical literature on the Italian Renaissance is older, larger, and perhaps more intimidating than that for any other period, a renewed look at old questions can be enlightening, as this exhibition and catalogue so capably demonstrate.