Written over nearly three decades, the fifteen essays involve the three a's of the title, art, agency, and appreciation. The first refers to the general subject matter of the book, Byzantine art, chiefly painting, of the twelfth through the fourteenth centuries, the second to its often human-like agency, and the last to its historical reception. Responding to different issues and perspectives that have animated art history and Byzantine studies in recent decades, the essays have wide theoretical range from art historical formalism, iconography, archaeology and its manuscript equivalent codicology, to statistics, patronage, narratology, and the histories of science and collecting. The series begins with art works themselves and with the imagery and iconography of church decoration and manuscript illumination, shifts to the ways that objects act in the world and affect their beholders, and concludes with more general appreciations of Byzantine art in case studies from the thirteenth century to the present.