Just Doing What Comes Naturally:  The Is-Ought Fallacy

 Gregory Koukl

      In a prior post I showed why justifying homosexuality as “natural” just won’t work.  It’s not “natural” in any meaningful sense of the word.  Today I want to build on that by explaining the logical fallacy at work in this argument that since same-sex attraction is natural for gays it must be moral.

      Columnist Robert Scheer noted that, “Homosexuality in the vast majority of cases is a condition that is given and not chosen, and must therefore be honored as part of the natural order of things.”  Scheer’s comments reflect a standard misconception about homosexuality and ethics:  If we can find a connection between homosexuality and nature, then we must surrender our moral objections to it.  The error is in thinking that one has anything to do with the other.  It doesn’t. 

      Philosopher David Hume argued that it is impossible to produce a deductively valid argument with factual premises and an ethical conclusion.  In short, you can’t get an “ought” from an “is.”  This is called the naturalistic fallacy. 

      In layman’s terms, just because a behavior is “natural” doesn’t make it right.  This is obvious on a moment’s reflection.  Does a natural tendency towards violence justify assault?  Does a natural desire for food justify theft?  Does a natural aversion to homosexuals justify gay-bashing?  Of course not.

      Animals do what comes naturally.  We are not beasts, we are human beings protected by morality from the tyranny of our natural appetites.  The difference between “just doing what comes naturally” and principled self-restraint is called civilization.

      Further, persisting in this line of reasoning annihilates the argument for adoption rights by homosexuals.  If homosexuality is right because it’s natural, then adoption must be wrong because it’s unnatural.  If nature dictates morality, and the natural consequence for homosexuals is to be childless, then it’s unnatural—and therefore immoral—for homosexuals to raise children.  Artificial insemination of lesbians or adoptions by homosexual couples would be wrong by their own argument.  The same principle governs both issues.

     The morality of homosexuality can never be defended by any appeal to nature, but only by an appeal to moral rules.  Nature alone can never provide us with those.  Nature merely tells us what is, not what ought to be.