Note 2 — Chapter I · DEFINITION AND DIVISIONS.
Reading edition
The term Deontology, from τὸ δέον [Greek: to deon], what is due or binding, and λόγος [Greek: logos], discourse, has been used by some modern writers as a fit designation of moral science. Though it has never come into general use, it is etymologically well adapted to express the element of obligation involved in the moral sense. See Krauth-Flemming Vocabulary of the Philosophical Sciences, p. 132.