Robert Sparrow — philosopher at Monash University in Melbourne — is the most influential voice in the debate on lethal autonomous weapon systems. His essay Killer Robots in the Journal of Applied Philosophy (2007) was the first to name and diagnose the responsibility gap as the specific problem of autonomous military systems.
Key Contribution
Sparrow argues: when a lethal autonomous weapon system kills a human being without human authorization, the deed cannot be imputed to anyone in the classical sense. Not to the programmer (who did not foresee the specific deployment scenario), not to the operator (who gave no authorization), not to the commander (who set only the general framework), and not to the machine (which, as a non-personal system, is incapable of guilt). Responsibility fragments — and precisely this fragmentation violates a fundamental requirement of jus in bello: every killing in war must be imputable to a personally identifiable instance.
From this Sparrow concludes the prohibition postulate: systems that structurally render this imputation impossible ought to be prohibited under international law. His position was institutionally taken up in 2013 by the UN Special Rapporteur initiative (Heyns report) and in 2025 by the UN General Assembly resolution (164 votes in favor).
Significance for the Ontology of the Person
The responsibility gap is the practical consequence of what the ontology of the person holds conceptually: only persons can bear responsibility, because only they possess freedom, conscience, and reason. A robot is something, not someone — it cannot be an addressee of imputation. Sparrow shows that every delegation of lethal decisions to autonomous systems structurally institutionalizes the oblivion of the person: where the machine kills, the question who is responsible? becomes systemically void — and with it the personal core of law is hollowed out.
Place in the Book
Sparrow supplies the military-ethical application of the concept of responsibility that the ontology of the person grounds metaphysically. He shows where the reduction of action to function leads in practice: into warfare without a perpetrator. This is the sharpest confirmation of Spaemann’s warning that the leveling of the someone-something distinction has catastrophic consequences not only theoretically but politically and practically.
See also
- Responsibility Gap
- Lethal Autonomous Weapon System (LAWS)
- Combat Drone
- Combat Robot
- Responsibility
- AI Ethics
- War
- Degree of Autonomy
- Robert Spaemann
Sources: Sparrow, Robert (2007): “Killer Robots”. Journal of Applied Philosophy 24(1), pp. 62–77.
Further sources:
- Sparrow, Robert (2016): “Robots and Respect: Assessing the Case Against Autonomous Weapon Systems”. Ethics & International Affairs 30(1), pp. 93–116.
- Heyns, Christof (2013): Report of the Special Rapporteur on extrajudicial, summary or arbitrary executions: Lethal autonomous robotics and the protection of life. UN Doc. A/HRC/23/47.
- United Nations General Assembly (2025): Resolution 80/57, Lethal Autonomous Weapons Systems (adopted in plenary, 1 December 2025; 164 in favor, 6 against, 7 abstentions).