What Is the Naturalistic Fallacy? | Definition & Examples

The naturalistic fallacy is the mistake of assuming that whatever is deemed natural is also morally good. An argument that commits this logical fallacy argues that the way things are is the way things should be without providing a logical rationale.

Naturalistic fallacies always involve claims about ethics or morality.

Naturalistic fallacy example
“Humans have always engaged in competing for resources, and taking a selfish approach helps ensure survival. Therefore, it is morally good to be selfish.

”The statement exemplifies the naturalistic fallacy by using natural human competitiveness as a moral justification for selfishness. The argument is weak because it doesn’t provide any logical rationale for equating natural behavior with morally good behavior.

The naturalistic fallacy is often found in discussions of what is morally “good,” in domains such as policymaking, philosophy, and religion.

What is the naturalistic fallacy?

The naturalistic fallacy is the mistake of thinking that if something happens in nature, it must be morally right.

This fallacy is closely related to the “is-ought problem,” identified by David Hume, which highlights the logical gap between descriptive statements (what is) and prescriptive statements (what ought to be).

It is an informal logical fallacy, meaning the problem lies in the argument’s content or context rather than its structure. Arguments that commit informal fallacies are considered unsound, rather than invalid.

The naturalistic fallacy bears similarities to several other fallacies:

  • Appeal to nature fallacy: Assumes that things are inherently valuable or good (e.g., aesthetically, health-wise, morally) if they are “natural”
  • Moralistic fallacy: Infers that if something is morally desirable, it must be true
  • Appeal to tradition fallacy: Claims that an idea or practice is correct because it has been believed or performed for a long time

The naturalistic fallacy is somewhat controversial because some philosophers argue that nature alone can provide a sufficient basis for determining morality. However, the prevailing view among philosophers is that deriving moral principles directly from natural facts without additional justification makes an argument weak.

Naturalistic fallacy examples

Examples of the naturalistic fallacy can be found in discussions of what actions and beliefs should be considered “good,” especially in domains such as philosophy and the social sciences.

Naturalistic fallacy example in social behavior
“Chimpanzees engage in violent conflicts similar to wars, suggesting that aggression is natural and intergroup violence is morally acceptable in humans.”

This argument commits the naturalistic fallacy by assuming that because violence occurs naturally in chimpanzees, it is morally acceptable for humans, without providing any supporting evidence or reasoning.

Naturalistic fallacies can also be found in the realm of politics and religion when observations from the natural world are used as the sole basis for a moral claim.

Naturalistic fallacy example in healthcare policy
“Universal healthcare is unethical because it disrupts natural selection. In society, survival should be determined by an individual’s ability to secure healthcare, reflecting the principle of the survival of the fittest.”

This argument falls into the naturalistic fallacy by equating the concept of “survival of the fittest”—a descriptive principle from evolutionary biology—with a normative judgment about healthcare policies.The argument rests on the assumption that what happens in nature inherently dictates what should happen in human society, overlooking the need for ethical reasoning and empirical evidence in forming policy decisions.

Naturalistic fallacy vs appeal to nature fallacy

The naturalistic fallacy and the appeal to nature fallacy share similarities and can overlap in some arguments. Both are focused on the superiority of things that are considered natural. However, there is a key difference:

  • Naturalistic fallacy: Conflates factual descriptions of the world (what “is”) with moral prescriptions (what “ought to be”), suggesting that facts about nature can directly inform moral values
  • Appeal to nature fallacy: Claims that natural things are inherently good and unnatural things are inherently bad, applying this judgment across various domains (not limited to morality)

In short, the naturalistic fallacy is focused on ethical judgments, whereas the appeal to nature fallacy encompasses a broader range of judgments beyond morality, including aesthetic values, health benefits, and practicality.

Why is the naturalistic fallacy a problem?

The naturalistic fallacy is problematic because it conflates what is natural with what is morally good or desirable. This reasoning is flawed for several reasons:

  • Lack of logical foundation: The fact that something is natural does not inherently make it good or right. Many natural phenomena can be considered harmful or undesirable.
  • Oversimplification of morality: Morality is complex and cannot be determined solely by observing what occurs in nature.
  • Ambiguity in defining “natural”: The element of subjectivity in determining what is “natural” complicates its use as a moral criterion.

How can you respond to the naturalistic fallacy?

To identify and respond to the naturalistic fallacy, consider the following strategies:

  • Separating descriptions from value judgments: Distinguish between statements about the way things are (descriptive) and the way things should be (prescriptive).
  • Appealing to ethical principles: Highlight where values such as fairness and compassion may conflict with observations about nature.
  • Providing counterexamples: Use examples to illustrate the fact that what’s natural isn’t always ideal or morally acceptable.

Frequently asked questions about naturalistic fallacy

What is the difference between the is-ought fallacy and the naturalistic fallacy?

The is-ought problem is related to the naturalistic fallacy, but there is a key difference:

  • The is-ought problem is the unjustified leap from descriptive statements (describing what “is”) to prescriptive statements (describing what “ought to be”).
  • The naturalistic fallacy is a specific instance of the is-ought problem, in which descriptions of natural phenomena are used to prescribe morality.
Who coined the term naturalistic fallacy?

The term “naturalistic fallacy” was coined by British analytic philosopher G. E. Moore in his 1903 work Principia Ethica. Moore argued against defining moral qualities such as “goodness” on the basis of observations about nature.

Did Hume write about the naturalistic fallacy?

David Hume did not use the term “naturalistic fallacy.” However, Hume’s thoughts on the problem of “is” vs. “ought” (first explored in A Treatise of Human Nature) influenced later discussions on the relationship between facts and values, including critiques of the naturalistic fallacy.

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Magedah Shabo

Magedah is the author of Rhetoric, Logic, & Argumentation and Techniques of Propaganda and Persuasion. She began her career in the educational publishing industry and has over 15 years of experience as a writer and editor. Her books have been used in high school and university classrooms across the US, including courses at Harvard and Johns Hopkins. She has taught ESL from elementary through college levels.