This paper argues that leprosy sufferers participated in the healing process of their ailment by engaging with colonial medical authorities on public health issues. Sufferers often expressed their opposition to colonial exploitation of their labor, underfeeding, and punitive withdrawal of their medication. By examining petition letters, this study shows how and why people with leprosy adopted the colonial language of vulnerability to advocate for improvement in leprosy settlements. Focusing on Uzuakoli and Oji-River, Southeastern Nigeria, the research treats these petition letters as rhetoric and keenly analyzes the persuasive language that leprosy sufferers and leprologists employed in constructing a leprous body. Beyond demonstrating how they engaged with colonial authorities, negotiated with doctors, and contested perceived obnoxious colonial policies, If Not the Work of Malice underscores resistance to labor exploitation in leprosy settlements. Employing these letters of the petition as both sources and methods of recovering the voices of ordinary people, especially people with leprosy, who inhabited the lowest strata of society, the paper contends that leprosy sufferers asserted their humanity, participated in the post-war anticolonial movement, and shaped colonial leprosy policies. Though their letters did not call for the end of colonial rule, events in the settlements affirm that leprosy colonies were not insulated from broader society. Other sources that aided the production of this work include medical reports on leprosy, scientific publications, and extant literature on disease and medicine in Africa. The paper concludes that people with leprosy constructed their knowledge about leprosy while in isolation and collectively articulated concerns that threatened their healing.