Ideal observer theory is the

meta-ethical In metaphilosophy and ethics, meta-ethics is the study of the nature, scope, and meaning of moral judgment. It is one of the three branches of ethics generally studied by philosophers, the others being normative ethics (questions of how one ought ...

view which claims that ethical sentences express truth-apt

proposition In logic and linguistics, a proposition is the meaning of a declarative sentence. In philosophy, " meaning" is understood to be a non-linguistic entity which is shared by all sentences with the same meaning. Equivalently, a proposition is the no ...

s about the attitudes of a hypothetical ''ideal observer''. In other words, ideal observer theory states that ethical judgments should be interpreted as statements about the judgments that a neutral and fully informed observer would make; "''x'' is good" means "an ideal observer would approve of ''x''". This makes ideal observer theory a subjectivist yet universalist form of cognitivism. Ideal observer theory stands in opposition to other forms of ethical subjectivism (e.g.

moral relativism Moral relativism or ethical relativism (often reformulated as relativist ethics or relativist morality) is used to describe several philosophical positions concerned with the differences in moral judgments across different peoples and cultures. ...

, and individualist ethical subjectivism), as well as to

moral realism Moral realism (also ethical realism) is the position that ethical sentences express propositions that refer to objective features of the world (that is, features independent of subjective opinion), some of which may be true to the extent that the ...

(which claims that moral propositions refer to objective facts, independent of anyone's attitudes or opinions),

error theory Moral nihilism (also known as ethical nihilism) is the meta-ethical view that nothing is morally right or wrong. Moral nihilism is distinct from moral relativism, which allows for actions to be wrong relative to a particular culture or indivi ...

(which denies that any moral propositions are true in any sense), and

non-cognitivism Non-cognitivism is the meta-ethical view that ethical sentences do not express propositions (i.e., statements) and thus cannot be true or false (they are not truth-apt). A noncognitivist denies the cognitivist claim that "moral judgments are ...

(which denies that moral sentences express propositions at all).

Adam Smith Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"——� ...

and

David Hume David Hume (; born David Home; 7 May 1711 NS (26 April 1711 OS) – 25 August 1776) Cranston, Maurice, and Thomas Edmund Jessop. 2020 999br>David Hume" '' Encyclopædia Britannica''. Retrieved 18 May 2020. was a Scottish Enlightenment ph ...

espoused versions of the ideal observer theory.

Roderick Firth Roderick Firth (January 30, 1917 – December 22, 1987) was an American philosopher. He was Professor of Philosophy at Harvard University from 1953 until his death. Education Firth earned his Ph.D. in philosophy from Harvard in 1943. His thesis ...

laid out a more sophisticated modern version. According to Firth, an ideal observer has the following specific characteristics: omniscience with respect to nonmoral facts, omnipercipience, disinterestedness, dispassionateness, consistency, and normalcy in all other respects. Notice that, by defining an Ideal Observer as omniscient with respect to nonmoral facts, Firth avoids

circular logic Circular may refer to: * The shape of a circle * ''Circular'' (album), a 2006 album by Spanish singer Vega * Circular letter (disambiguation) ** Flyer (pamphlet), a form of advertisement * Circular reasoning, a type of logical fallacy * Circular ...

that would arise from defining an ideal observer as omniscient in both nonmoral and moral facts. A complete knowledge of morality is not born of itself but is an emergent property of Firth's minimal requirements. There are also sensible restrictions to the trait of omniscience with respect to nonmoral facts. For instance, to make a moral judgment about a case of theft or murder on

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...

it is not necessary to know about geological events in another

solar system The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

. Those using the ideal observer theory do not usually assert that ideal observers actually exist. An analogous idea in law is the

reasonable person In law, a reasonable person, reasonable man, or the man on the Clapham omnibus, is a hypothetical person of legal fiction crafted by the courts and communicated through case law and jury instructions. Strictly according to the fiction, it i ...

criterion.

References

External links

Impartiality
in the

Stanford Encyclopedia of Philosophy The ''Stanford Encyclopedia of Philosophy'' (''SEP'') combines an online encyclopedia of philosophy with peer-reviewed publication of original papers in philosophy, freely accessible to Internet users. It is maintained by Stanford University. E ...

{{Ethics Emergence Ethical theories Meta-ethics Point of view Thought experiments in philosophy