deontology

The story

1. Proto-Indo-European · derived from*deh₁-“to bind”
2. Ancient Greek · learned borrowing fromδέον“that which is binding, needful, proper, or right”
3. English todaydeontology

Learned borrowing from Ancient Greek δέον (déon, “that which is binding, needful, proper, or right”) + English -ology (variant of -logy (suffix denoting a branch of learning or a study of a particular subject)). Δέον (Déon) is the neuter present participle of δεῖ (deî, “it behoves one to, it is necessary to, one must”), from δέω (déō, “to bind, tie; to fasten; to fetter”), ultimately from Proto-Indo-European *deh₁- (“to bind”). Sense 1 (“synonym of ethics”) was coined by the English philosopher Jeremy Bentham (1748–1832) to refer to censorial or dicastic ethics (ethics based on judgment), while sense 1.1 (“normative ethical theory that the morality of an action should be based on whether the action follows certain obligations or rules”) derives from the use of the word deontological by the English philosopher Charlie Dunbar Broad (1887–1971) in his book Five Types of Ethical Theory (1930).

Words from the same roots

First known use, by meaning

• from c. 1826 Synonym of ethics (“the study of principles relating to right and wrong conduct”).
• from c. 1826 The normative ethical theory that the morality of an action is based on whether the action follows certain obligations or rules, rather than on its inherent goodness, consequences, etc.