Joseph Salvatore Ackley studies the art and architectural traditions of medieval Europe. His scholarship explores precious metalwork, such as chalices, reliquaries, figural statuettes, and jewelry, as well as what might be called the “radiant aesthetic” across a variety of media traditions, including panel painting, polychrome wood sculpture, manuscript illumination, and the late medieval altarpiece. Additional research interests include questions of medium, matter, and material identity; natural philosophy, alchemy, and the medieval encyclopedia; the historiography of the so-called “decorative arts”; and, more broadly, what can be loosely termed “the problem of the substrate,” that is, the visual tension between a surface and its underlying substance.

Ackley’s current book project, Medieval Gold: The Radiant Medium, interrogates gold as a material and medium and its significance and use within precious metalworking traditions of medieval Europe; the project argues in general for the centrality of metalwork, and the gloriously multimedia aesthetic overall, to medieval art. With Shannon L. Wearing he co-edited Illuminating Metalwork: Metal, Object, and Image in Medieval Manuscripts (Berlin: De Gruyter, 2022), a volume of fifteen essays exploring the use of metallic media in manuscript decoration and the painted depiction therein of precious metalwork. Recently published and forthcoming essays include studies of precious-metal figuration in the late Middle Ages; late medieval winged “treasury altarpieces”; the concept and definition of the medieval mechanical arts (artes mechanicae); church treasury inventories; the monk-goldsmith Tuotilo of St. Gall (d. c. 913) and late Carolingian metalwork; and the historiography of the medieval "decorative arts," especially in late nineteenth-century Austria and Germany.

Ackley’s research has received support from The Metropolitan Museum of Art, the Alexander von Humboldt Stiftung, the International Center of Medieval Art (ICMA), the Kress Foundation, the Deutscher Akademischer Austausch Dienst (DAAD), the Stiftung Preußischer Kulturbesitz - Kunstgewerbemuseum, and the N.Y.U. Global Research Initiative, among other organizations. He held a Mellon Postdoctoral Fellowship at Columbia University from 2014 to 2016.  Before coming to Wesleyan Ackley taught at Barnard College, Columbia, Colorado College, and the University of Arkansas.