In this article I examine the origins and progression of the practice of vivisection in roughly the first half of the sixteenth century, paying particular attention to the types of vivisection procedures performed, the classical sources for those procedures and the changing nature of the concerns motivating the anatomists who performed them. My goal is to reexamine a procedure typically treated as something revived by Vesalius from classical sources as a precursor to early modern discoveries by placing the practice of (...) vivisection in its sixteenth-century context. There were a variety of reasons for employing vivisection in the sixteenth century, including exploring the differences between living and dead bodies, considering how parts of the body worked, and advocating the entirely new idea of the pulmonary transit. By exploring the discussions of Berengario, Niccolò Massa, Vesalius, Colombo and Juan Valverde I try to elaborate on these various reasons and their origins. (shrink)