What it is to be a martial art: autoimmunity and the essentialist programme

Is ‘martial arts’ a stable kind with a real essence, or a contingent label? I defend sortal essentialism. Martial arts are combat systems designed for interpersonal violence, built on a reciprocal attack-defence relation I call autoimmunity. Every attack has at least one defence drawn from the same general principles, themselves organised around each art’s specific principle. Autoimmunity works at two levels. The general principles separate martial arts from other competitive practices, while the art-specific principle individuates, telling one art from another. The diverse techniques of an art therefore form one whole, not a list. That solves the unity problem for complex essences. I answer four objections to essentialism, then argue abductively: autoimmunity explains why historically independent traditions converge on the same relational teaching method. Sortal essentialism thus reaches beyond natural kinds to a designed, socially transmitted practice, and the ontological status of martial arts becomes clear enough to build on.