Deontic Logic and Changing Preferences

Abstract

The normative realm involves deontic notions such as obligation or permission, as well as information about relevant actions and states of the world. This mixture is not static, given once and for all. Both information and normative evaluation available to agents are subject to changes with various triggers, such as learning new facts or accepting new laws. This paper explores models for this setting in terms of dynamic logics for information-driven agency. Our paradigm will be dynamic-epistemic logics for knowledge and belief, and their current extensions to the statics and dynamics of agents’ preferences. Here the link with deontics is that moral reasoning may be viewed as involving preferences of the acting agent as well as preferences of moral authorities such as lawgivers, one’s conscience, or yet others. In our presentation of preference based agency, we discuss a large number of themes: primitive ‘betterness’ order versus reason-based preferences (employing a model of ‘priority graphs’), the entanglement of preference and informational attitudes such as belief, interactive social agents, and scenarios with longterm patterns emerging over time. Specific deontic issues considered include paradoxes of deontic reasoning, acts of changing obligations, and changing norm systems. We conclude with some further directions, such as multi-agency and games, plus pointers to related work, including different paradigms for looking at these same phenomena.