There is no universally accepted method of engineering ethics. However, the absence of a single, universally accepted method does not entail that all methods are equally good or that “anything goes.” Some methods, views, and positions are clearly more coherent and nuanced than others.
The distinction between facts and values is central to nearly all discussions of ethics. People who disagree on some moral issue may do so because they disagree on what the relevant facts are or because they do not accept the same value judgments. The Scottish philosopher David Hume (b. 1711–d. 1776) famously pointed out that many moral arguments begin with a set of nonmoral claims and then proceed to a moral claim without clarifying the relation between the moral and nonmoral claims. According to what is commonly known as Hume’s law, no moral claims can be derived from purely nonmoral premises.
Metaethics is the subfield of ethics that tries to answer questions about the nature and status of moral claims. Metaethical theories are thus theories about ethics, not theories about what someone ought to do or what actions are morally right or wrong. Four of the most prominent metaethical theories are ethical objectivism, ethical nihilism, ethical constructivism, and ethical relativism. Normative ethical theories seek to establish what features of the world make right acts right and wrong ones wrong. Ethical theories are often summarized in general moral principles: “Never treat others merely as a means to an end!” or “Only perform actions that lead to optimal consequences.