Sex and Fallacious Reasoning

Like most people, I am keenly aware the reason you do not often see "sex" and "logical fallacies of relevance" in the same sentence together is because logical fallacies of relevance are intrinsically so exciting they do not need sex to sell them.

Merely mention one of the numerous fallacies of relevance -- say, the Ad Hominem Fallacy, the Red Herring Fallacy, or the Naturalistic Fallacy -- and you create an atmosphere of tingling anticipation.  To toss "sex" into the mix would only be overkill.
  
So it may astonish my readers that I am about to bring up both the Naturalistic Fallacy and the subject of biological reproduction -- together.

Make no mistake about it, though:  I am not mixing sex with pleasure logic merely in order to titillate you, my beloved readers.  Nor am I mixing sex with logic merely because I am a  man of passions -- strong, huge, even alarming passions.  No, there is nothing gratuitous about this.  Instead, it has simply become necessary to mention the two together.

And why is that?  Because someone -- someone! -- has made a mistake on the internet!  That is, they have committed the Naturalistic Fallacy in the all but certain presence of impressionable children. Children who might now grow up to promiscuously introduce fallacies into the very core of their reasoning.  Children who might one day run large multinational corporations, huge NGOs, entire governments, or even departments of philosophy.   DOESN'T ANYONE THINK OF THE FUTURE OF OUR SPECIES BEFORE THEY COMMIT FALLACIES OF RELEVANCE ANYMORE?

The person in question -- let us call him the "perpetrator" -- committed the fallacy in the course of arguing that we should derive our morals from "evolutionary biology".  Allow me to quote:

My position is that evolutionary biology lays on us certain [moral] absolutes. These are adaptations brought on by natural selection to make us functioning social beings. It is in this sense that I claim that morality is not subjective. [bracketed material mine]

As it happens, there is more than one way to lay out his argument. In the spirit of good sportsmanship, I shall now lay out the perpetrator's argument in the strongest possible manner I can come up with, despite the risk of giving us all the vapours:

• We evolved various behaviors ("adaptations") that make us functioning social beings.
• Because the evolved behaviors ("adaptations") make us functioning social beings, they are moral absolutes.
• We ought to behave according to moral absolutes.
• Therefore, we ought to behave according to the various behaviors ("adaptations") that make us functioning social beings.

As you see, the second premiss is the offending one.  It constitutes a mini-argument within the larger argument, for it has the form of a premiss ("our evolved behaviors make us functioning social beings") and a conclusion ("our evolved behaviors are therefore moral absolutes"). 

But that is precisely the form of the Naturalistic Fallacy, which can be described as, "An argument whose premises merely describe the way that the world is, but whose conclusion describes the way that the world ought to be...."  The Naturalistic Fallacy is a fallacy because you cannot reason from an "is" to an "ought".

If you could reason from an "is" to an "ought", you could reason all sorts of ridiculous things. "There is theft, therefore there ought to be theft." "There are wars, therefore there ought to be wars."  Even, "There are murderous fallacies of logic, therefore there ought to be murderous fallacies of logic."

Yet, for the moment, let us accept the perpetrator's reasoning, despite it's power to shock us.  What, then, might happen if we were to buy into his notion that "evolutionary biology lays on us certain [moral] absolutes?

Would not any behavior with a genetic basis that increased someone's reproductive success then become moral? I cannot see why it would not.

For instance, it appears that war has a genetic basis in territorial instincts and other such things.  But if that is so, then wars would be moral if they increased someone's reproductive success.  Again, there is a hypothesis that rape has a genetic basis.  But if that is so, then rape would be moral if it increased someone's reproductive success.

Such implications must disturb even the calmest of men and women.  To permit the notion that evolutionary biology lays on us moral absolutes seems to invite a deluge of undesirable consequences.  Fortunately we need not permit it, for sound logic does not compel us to permit it. For that, and for other reasons, men and women of conscience may justifiably and emphatically wag their fingers while saying to the perpetrator in the most passionate terms, "Buffoonery! Mr. Perpetrator, your notion is buffoonery!"