Agency and Deontic Logic

John Horty effectively develops deontic logic (the logic of ethical concepts like obligation and permission) against the background of a formal theory of agency. He incorporates certain elements of decision theory to set out a new deontic account of what agents ought to do under various conditions over extended periods of time. Offering a conceptual rather than technical emphasis, Horty's framework allows a number of recent issues from moral theory to be set out clearly and discussed from a uniform point of view.

2.1 - Branching time
2.1.1 - Frames and Models
2.1.2 - 2.1.2 Propositions
2.2 - Individual agency
2.2.1 - Agents and choices
2.2.2 - Stit operators
2.2.3 - Some logical considerations
2.3 - Individual ability
2.3.1 - Kenny's objections
2.3.2 - Brown's theory
2.3.3 - Refraining and ability
2.4 - Group agency and ability
2.4.1 - Group actions
2.4.2 - A group agency operator
3.1 - The standard theory
3.2 - A utilitarian theory
3.2.1 - General models
3.2.2 - Utilitarian models
3.2.3 - Logic of the utilitarian ought
3.3 - The Meinong/Chisholm analysis
3.3.1 - The analysis
3.3.2 - Some logical features
3.4 - Evaluating the analysis
3.4.1 - Agency in the complement
3.4.2 - The gambling problem
4.1 - Dominance
4.1.1 - Ordering the propositions
4.1.2 - A sure-thing argument
4.1.3 - Ordering the actions
4.2 - Dominance act utilitarianism
4.2.1 - Optimal actions
4.2.2 - The finite choice condition
4.3 - A new deontic operator
4.3.1 - The definition
4.3.2 - Deontic logic and act utilitarianism
4.3.3 - Logic of the dominance ought
4.4 - Independence
4.4.1 - Independence and conditionals
4.4.2 - Conditionals and sure-thing reasoning
4.4.3 - Refining the analysis
5.1 - Conditionally optimal actions
5.2 - A conditional operator
5.2.1 - The definition
5.2.2 - Some logical considerations
5.3 - Two patterns of argument
5.3.1 - The action argument
5.3.2 - The ought argument
5.4 - Orthodox act utilitarianism
5.4.1 - An example
5.4.2 - The definition
5.4.3 - An orthodox deontic operator
6.1 - Optimal group actions
6.2 - Individual and group act utilitarianism
6.3 - Deontic operators for group oughts
6.3.1 - Definitions
6.3.2 - Some logical points
6.4 - Rule utilitarianism
6.4.1 - Formulating the theory
6.4.2 - Act and rule utilitarianism
7.1 - Strategies
7.1.1 - Basic idea
7.1.2 - Limiting the range
7.2 - Strategies and choices
7.2.1 - Agency
7.2.2 - Ability
7.3 - Strategic dominance and optimality
7.3.1 - Dominance
7.3.2 - Optimality
7.4 - A strategic ought operator
7.4.1 - The definition
7.4.2 - Logical points
7.4.3 - Actualism and possibilism
A - Proofs of validities and propositions
A.1 - Validities
A.2 - Propositions

John Horty is a Professor in the Philosophy Department and the Institute for Advanced Computer Studies at the University of Maryland. He is the author of Frege on Definitions (Oxford, 2007) as well as papers on a variety of topics in logic, philosophy, and computer science.