deontic logic

9.9

A field that studies rules about what people must or may do

noun
/diˈɒntɪk ˈlɒdʒɪk/

Specialized

: lógica deóntica

Philosophers often use deontic logic to analyze ethical dilemmas involving duty and permission.

Examples

The study of deontic logic helps us understand moral obligations.
The formalization of legal systems can benefit from tools developed in deontic logic.
Courses in advanced philosophy sometimes include modules on deontic logic and its applications.
Many philosophers debate the principles of deontic logic.
Philosophers often use deontic logic to analyze ethical dilemmas involving duty and permission.
Courses in advanced philosophy sometimes include modules on deontic logic and its applications.
The formalization of legal systems can benefit from tools developed in deontic logic.

Surface Forms

deontic logic singular

deontic logics plural

Morphology

deontic + logic

The meaning is directly compositional: 'deontic' means relating to obligations and permissions and 'logic' denotes a branch of philosophical/theoretical study, so 'deontic logic' straightforwardly denotes the branch of logic about obligation and permissibility. This is a regular noun–noun technical compound following productive English formation (and similar constructions exist cross-linguistically), so a learner who knows both constituents will readily infer the MWE meaning.

Etymology

Deontic logic comes from an old Greek word 'deon' meaning 'duty' or what you 'must' do, and from logic, the study of clear thinking and rules. So deontic logic is the name for using formal rules to talk about what people 'must' do and what is 'allowed'.