The Naturalistic Fallacy
Moore’s naturalistic fallacy concerns defining goodness in terms of a natural property, such as pleasure. His objection is related to, but distinct from, deriving an ought from an is or claiming that natural behavior is morally right.
THE IDEA
Overview
The naturalistic fallacy, as articulated by G.E. Moore in Principia Ethica (1903), concerns what Moore regarded as the error of defining 'good' in terms of some natural property (e.g., pleasure, desire, evolutionary fitness). Moore argued that 'good' is a simple, non-natural property that cannot be analyzed or reduced to natural properties without committing a fallacy. The fallacy is closely related to the 'is-ought' problem (Hume's guillotine), though Moore's formulation is specifically about the definition of moral terms.
Key Points
- Open question argument: For any proposed natural definition of 'good', we can meaningfully ask, "But is X really good?" Moore argues that the openness of this question shows that the proposed definition does not capture the meaning of 'good'.
- Distinction from Hume's is-ought: While Hume warns against deriving 'ought' from 'is', Moore's fallacy is about defining 'good' in natural terms, even when 'ought' is not directly derived.
- Examples:
- "This action maximizes pleasure, therefore it is good" (assuming pleasure = good).
- "This behavior is natural in humans, therefore it is morally right" (appeal to nature).
References
- Frankena, William. 1939. “The Naturalistic Fallacy.” Mind 48(192): 464–477.
- Hurley, Patrick. 2008. A Concise Introduction to Logic, 10th edition. Belmont, CA: Wadsworth Cengage Learning.
When to use it
Evaluating ethical arguments in philosophy papers or policy discussions.
Debunking fallacious reasoning in advertising that equates 'natural' with 'good'.
Analyzing psychological research that attempts to derive moral norms from descriptive studies of human behavior.
Teaching critical thinking and logical fallacies in education.
FROM THEORY TO EVERYDAY LIFE
In practice
Pleasure as Good
A hedonist argues: 'Pleasure is good. Therefore, any action that produces pleasure is morally right.' Calling pleasure good does not by itself define goodness as pleasure. Moore’s objection applies when the argument identifies goodness entirely with that natural property; the move to the rightness of every pleasure-producing act needs further premises as well.
Evolutionary Ethics
Some claim: 'Evolution has shaped us to cooperate, so cooperation is morally right.' This fallacy assumes that biological tendencies (natural facts) directly indicate moral values.
A MOMENT TO REFLECT
Put it to work.
Identify a recent argument in a public debate that seems to derive a moral conclusion from a natural fact. How could the naturalistic fallacy apply?
Why does the open question argument challenge naturalistic definitions of 'good'?
Can you think of a case where a natural property (e.g., health) might legitimately be considered part of what is 'good' without committing the fallacy?
Often confused with
References
- The Naturalistic Fallacy — Frankena, William (1939)
- A Concise Introduction to Logic — Hurley, Patrick (2008)
CONTINUE THE CONVERSATION
Source texts
- Bad Arguments 100 of the Most Important Fallacies in Western Philosophy (Steven Barbone, Michael Bruce)