The Legal Basis for the Innovated Nissāraṇīya as an Additional Penalty for Nuns Committing a Saṅghādisesa Offense

The term “nissāraṇῑya” in the Pali Bhikkhunī-Vinaya signifies a mandatory, additional penalty of nissāraṇa (ejection) executed via pabbājanīyakamma (the legal act of temporary banishment) for every saṅghādisesa offense. This study demonstrates that this supplementary sanction is not an original feature of monastic law but a deliberate codification that extends beyond standard redress procedures. I argue that the historical trajectory of nissāraṇīya was shaped by three interconnected legal developments: (1) a departure from the “A-for-A” principle of precise case-penalty correspondence; (2) a strategic expansion of the Saṅgha’s legislative authority; and (3) an institutionalized tendency towards the compounding of penalties. By analyzing the inclusion of saṅghādisesa offenders within the subject lists of legal acts, this research reveals how the Saṅgha gained the discretionary power to impose nissāraṇa as a “logical” consequence of moral failure. Crucially, I identify a pivotal lexical innovation—the lengthening of the vowel from the original nissaraṇīya to the causative nissāraṇīya—as the mechanism that formalized this gender-specific sanction. This transition marks a fundamental shift in Pali monastic jurisprudence, where linguistic adjustment served to institutionalize the Saṅgha’s sovereign authority over the female Saṅgha.