de·on·tol·o·gy 
(dē′ŏn-tŏlə-jē)
(dē′ŏn-tŏlə-jē)n. pl. de·on·tol·o·gies
1. Ethical or moral theory concerned with duties and rights.
2. The doctrine that ethical status of an action lies in its adherence to a set of rules.
[Greek deon, deont-, obligation, necessity (from neuter present participle of dein, to need, lack; see deu-1 in the Appendix of Indo-European roots) + -LOGY.]
de·on′to·logi·cal (-tə-lŏjĭ-kəl) adj.
de·on′to·logi·cal·ly adv.
de′on·tolo·gist n.