In cosmopolitan port-cities across sixteenth- and seventeenth-century Southeast Asia, a variety of healers plied their trade. Changing patterns of commerce brought new materia medica, new ideas about sickness and health, and new approaches to prophylaxis against misfortune, disease, and disaster. Movements of religious proselytization and reform across the region similarly expanded the range of materials, strategies, and skilled personnel available to call upon in times of crisis. These bustling, complex, multilingual cities became crucial nodes in a global exchange of information and ideas about the causes of ill health, and of methods to restore well-being.

This paper focuses on one relatively overlooked aspect of this exchange: healing practices and beliefs sought out by those who were apparently tormented by, or sickened due to the actions of ghosts or spirits. Drawing on several inter-linked case studies from across Southeast Asia, I examine varied understandings of entities such as spirits and ghosts as causative, and sometimes curative, agents. I examine how such entities were defined and described in different cultural, religious, and medical traditions. I demonstrate how meanings and understandings could shift as they were debated and contested during moments of intercultural exchange. I argue for a reconsideration of how ‘healing’ was understood, showing that it was a process which could continue even after the death of a particular patient.

I consider too how different theorists and practitioners sought to distinguish ‘genuine’ apparitions or spiritual causation from illusions or misapprehensions. I show how examining understandings of vision(s) and hallucination in comparative perspective across these case studies provides fresh insight into the development of these topics in early modern scientific and religious thought.

I show how “medicine for ghosts” became a sphere of particularly rapid innovation in the world of maritime Asia. Through this lens, I explore the complexities of translation across linguistic, cultural, and religious boundaries.