Introducing Divine-Command Robot Ethics ∗ Selmer Bringsjord & Joshua Taylor Department of Computer Science Department of Cognitive Science Rensselaer Polytechnic Institute (RPI) Troy NY 12180 USA selmer@rpi.edu • tayloj@rpi.edu 062310 Abstract Perhaps it is generally agreed that robots on the battlefield, especially if they have lethal power, should be ethically regulated. But in what does such regulation consist? Presumably in the fact that all the significant actions performed by such a robot are in accordance with some ethical code. But then the question arises as to which code. One possibility, a narrow one, is that the code is a set of “rules of engagement” affirmed by some nation or group. Another possibility is that the code is a utilitarian one represented in computational deontic logic, as explained elsewhere by Bringsjord and colleagues. Another possibility is likewise based on computational logic, but with a logic that captures some other mainstream ethical theory (e.g., Kantian deontology, or Ross’ “right mix” direction). But there is another radically different possibility that hitherto has not arrived on the scene: viz., the controlling code could be viewed by the human as coming straight from God. There is some very rigorous work in ethics along this line, which is known as divine-command ethics. In a world in which human fighters and the general populations supporting them often see themselves as indeed championing God’s will in war, divine-command ethics is quite relevant to military robots. This chapter introduces divine-command ethics in the form of the computational logic LRT ⋆ , intended to eventually be suitable for regulating a real-world warfighting robot. Contents 1 Introduction 1 2 The Context for Divine-Command Roboethics 1 2.1 Tripartite Partition of Ethics ........................................................ 1 2.2 Where Our Work Falls ............................................................ 3 2.3 The Importance of Robot Ethics ...................................................... 3 2.4 Necessary and Sufficient Conditions for an Ethically Correct Robot ................................... 4 2.5 Four Top-Down Approaches to the Problem ................................................ 5 2.6 What About Divine-Command Ethics as the Ethical Theory? ...................................... 8 3 The Divine-Command Logic LRT ⋆ 8 3.1 Introduction and Overview of the Section ................................................. 8 3.2 Roots in C. I. Lewis ............................................................. 9 3.3 Modern Versions of the Propositional and Predicate Calculi, and Lewis’ S5 ............................... 9 3.4 LRT, Briefly ................................................................. 12 3.5 The Logic LRT ⋆ in a Nutshell ....................................................... 13 3.6 A Roboethics Scenario ............................................................ 14 4 Concluding Remarks 16 References 18 * We are indebted to Roderick Chisholm for seminal work on logic-based ethics, and to Phil Quinn for his ingenious extension of this work in the divine-command direction. Thanks are due to Bram van Heuveln for text describing the three-way breakdown of ethics given herein, created with Bringsjord for the National Science Foundation for other purposes.