An Original Examination of the Doctrine of Mafsada (Harm) in Islamic Jurisprudence and Its Application to Public Health Law in Northern Nigeria

The Islamic jurisprudential doctrine of Mafsada (harm) provides a foundational principle for legal prohibition and restriction across multiple domains of Islamic law, and its systematic theoretical development as a public health law instrument has received inadequate scholarly attention despite its significant implications for health governance in northern Nigerian states with Sharia legal frameworks. This study develops an original examination of the Mafsada doctrine and its theoretical and applied potential as a basis for public health law in northern Nigeria. A theoretical and empirical doctrinal methodology is applied. The theoretical component constructs a comprehensive typology of Mafsada from classical Fiqh sources (Al-Izz ibn Abd al-Salam, Al-Shatibi, Al-Raysuni), developing a hierarchy of harm classification ranging from Mafsada al-Daruriyya (fundamental harm to the five objectives of Islamic law) to Mafsada al-Hajiyya (significant but non-fundamental harm) and Mafsada al-Tahsiniyya (harm to betterment). The empirical component analyses thirty northern Nigerian Sharia court decisions and twenty Fatawa from 2015 to 2023 involving public health questions (vaccination, epidemic containment, food safety, drug regulation) to evaluate how the Mafsada doctrine has been applied. The study generates an original Islamic Public Health Law Framework incorporating Mafsada-based standards for health regulation, epidemic response authority, and vaccination obligation. Available Islamic health law literature from northern Nigeria identifies inadequate doctrinal articulation of Islamic health regulatory authority as the primary gap in pandemic response governance. Keywords: Mafsada, harm doctrine, public health law, northern Nigeria, Islamic jurisprudence.