Ethic - ethics
Ethic and ethics both come from the Greek word ethikos, which is the adjective from ethos (character or disposition) and means 'related to character'. (The adjective ethikos was famously used by the philosopher Aristotle (384-322 BCE) when he distinguished between good qualities of character or good moral qualities (ethikai aretai), on the one hand, and good qualities of mind or good intellectual qualities (dianoetikai aretai), on the other.)
There is a subtle difference of meaning between ethic and ethics.
- Ethic refers to the set of moral values and principles which, taken collectively, guide and influence the life of a group or, less commonly, of an individual. We may speak, e.g., of the Puritan ethic, i.e., the set of moral values and principles which guide the lives of those who, like the Puritans, attach value to austerity and the rejection of sensual and worldly pleasures; or of the work ethic, i.e., the set of moral values and principles which guide the lives of those who believe in the moral value of work.
- Ethics (in the plural) is the code of behaviour considered appropriate to a particular group, especially a group defined by its occupation or profession. We may speak, e.g., of medical ethics, i.e., the code of behaviour that is considered appropriate for doctors, nurses, etc., in treating their patients; or of military ethics, i.e., the code of behaviour that is considered appropriate for soldiers and other members of the armed services. (You may like to think about the difference between military ethics and a military ethic.)
- The word ethics has another, rather different meaning. Ethics - and notice that despite the 's' ethics in this use is singular - is the branch of philosophy which studies questions about the nature of morality and related questions, e.g., 'Do moral judgments state facts or do they merely express the feelings of the speaker?', 'Do human beings have free will?' An alternative expression for ethics in this sense is moral philosophy.