Naturalistic Fallacy


The argument tries to draw a conclusion about how things ought to be based on claims concerning what is natural, as if naturalness were itself a kind of authority.



The Naturalistic Fallacy involves two ideas, which sometimes appear to be linked, but may also be teased appart:

Appeal to Nature. One aspect of the Naturalistic Fallacy is the (false) idea that whatever is natural cannot be wrong. Hence, if we can find an example of a certain behavior "in nature," then that behavior should be acceptable for human beings. More generally, the appeal to nature is the idea that "natural" things are better than "artificial" things.

Deriving 'ought' from 'is'. Another aspect of the Naturalistic Fallacy is a move from a "fact," i.e. a declarative or descriptive utterance, to an imperative or prescriptive utterance. The conclusion may be about moral duties or about ideal states of affairs; but the unstated (and false) premiss is that we must always accept things as they are.

In some cases, the Naturalistic Fallacy can be very difficult to distinguish from the fallacy of Appeal to Tradition. The difference is that the Appeal to Tradition appeals to how things were done by our own ancestors as they have been passed down to us. The Naturalistic Fallacy appeals to how things are done by non-human animals or by groups of humans that we would consider to be "primative," and certainly outside of our own tradition.



"Tigers eat meat, so vegetarians must just be wrong."


"According to the Theory of Evolution, the best creatures will survive. Therefore, we shouldn't make special efforts to feed the poor. If they don't survive, that just means they weren't as fit as we are."


"There have always been wars. Hence, there is no reason for you to object that our bombing of Syria would be morally wrong."



The Naturalistic Fallacy gets much of its force from a feeling that we cannot condemn anything that is "natural." Perhaps this feeling comes from the fact that, in general, we do not make moral judgments outside the scope of human affairs. Many species survive by engaging in behavior that we would not like to see in humans. My favorite example is the mite Adactylidium in which the young are never laid as eggs. Rather, they hatch inside the mother's body, and then eat her from the inside out! We make no moral judgment, because it is, after all, "nature."

However, once we have acquired the habit of refraining from moral judgments outside the human realm, the Naturalistic Fallacy then tries to convince us that, since everything "natural" is morally acceptable, we ought to condone, within the context of human affairs, whatever can be described as natural. "Nature" may mean, of course, other species, but it may also include humans in a more "natural" state (i.e. non-civilized human societies.) The claim that something is natural may even just be an appeal to human nature, civilized or not. For example, in The African Queen Humphrey Bogart tries to justify his drinking of rum by saying, "Have a heart, miss. It's in me nature." (To which Katherine Hepburn replies, "Nature, Mr. Ornat, is what we were put into this world to rise above!")

David Hume is the philosopher most associated with the principle that one cannot validly derive and "ought" statement from an "is" statement, although G. E. Moore made good use of this principle in his Principia Ethica. The principle is sound, of course. From the claim that a ring is made of gold it does not directly follow that the ring is valuable, unless we also know that gold is valuable. On the other hand, "ought" arguments do often turn on a consideration of facts. Whether we should spend more on education may depend upon specific facts about student performance; whether we should spend more on the military depends upon specific facts about the current state of the military and about threats to this country. Hence, one way to reason badly is to propose an argument about what we ought to do, but omit or misrepresent all the relevant facts.

Moreover, the distinction between facts and values is not always clear cut. If I say, "This steel beam is strong," I probably mean that it is strong enough to serve some purpose, such as supporting a bridge. I am, in short judging its value to someone for some purpose. The concept of "strength" seems objective enough, but it is actually quite value-laden. Good reasoning recognizes this subtle interplay between fact and value.

The Naturalistic Fallacy mimics good reasoning by claiming to be factually based, i.e. by appealing to well-established facts. However, it is doing so in a context in which a choice of ideals is actually at issue, and the facts are beside the point. It does not so much recognize the interplay between fact and value as try to reduce questions of value to mere questions of fact.


Source: David Hume may have been the first to describe this fallacy, but it was named by G. E. Moore in Principia Ethica, 1903.


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