What is the naturalistic fallacy?

In metaethics, the naturalistic fallacy is the claim that it is a mistake to define the concept of 'good' in terms of purely descriptive properties or processes like pleasant, desirable, or evolutionary fitness. The term was originally introduced by philosopher G. E. Moore in his 1903 book Principia Ethica. It is closely related to, though distinct from, David Hume's is-ought problem.

What we know

• The naturalistic fallacy asserts that defining 'good' in terms of merely described entities, properties, or processes is fallacious. [1, 2]
• The term was introduced by British philosopher G. E. Moore in his 1903 work Principia Ethica. [2]
• Moore's naturalistic fallacy is closely related to the is-ought problem formulated by David Hume. [2]
• Unlike Hume's view of the is-ought problem, Moore and other ethical non-naturalists did not consider the naturalistic fallacy to be at odds with moral realism. [2]

Where to go next

• compared withWhat is the is-ought problem?
• whoWho was G. E. Moore?
• the bigger pictureWhat are informal fallacies?
• how it workedWhat is moral realism?
• a case in pointWhat are fallacies of definition?
• an unexpected connectionHow does defining terms lead to informal reasoning errors?Both the naturalistic fallacy and fallacies of definition show how improper attempts to define fundamental concepts can cause failures in philosophical and logical reasoning.

Sources

• [1]naturalistic fallacy (Wikidata Q376789) · CC0 1.0
• [2]Naturalistic fallacy · CC BY-SA 4.0
• [3]Fallacies of definition · CC BY-SA 4.0
• [4]List of fallacies · CC BY-SA 4.0
• [5]Fallacy · CC BY-SA 4.0