Cow’s milk is meant for baby cows. Which helps explain why this foodstuff is a leading cause of unwanted reactions to foods that can give rise to a variety of health issues such as nasal congestion, sinusitis, eczema and asthma.
Dr John Briffa, Observer Food Monthly, August 2004

Don’t get me started on “health food”. Doesn’t anyone smell a rat when they go into a shop dedicated to “natural” remedies only to be confronted by rows and rows of bottles, pills and supplements? Why is it that it seems every infusion in the world is good for you except for the everyday, normal tea we know and love? Why are stimulants such as guarana considered good while caffeine is bad? Why are the cereals we eat all the time, such as wheat, to be avoided while all the others are fantastically healthy? Do you detect a pattern here? The only principle I can see that explains all this is that the purpose of health food shops is to make life as awkward as possible by banning us from consuming all the common foodstuffs that surround us. Virtue means taking the hard path.

But I digress, before I’ve even started. The problem with Dr Briffa’s argument about cow’s milk is not that it is an example of this kind of demonising of the everyday staple. (Although it might be that too – funny how goat’s milk is usually considered to be healthy.) No, Briffa’s argumentative aberration (which is what I’m supposed to be focusing on) is that he fails to account for the fact that the origins of something may not tell us what we need to know about its present use or nature.

Even if we allow ourselves to talk loosely about what things in nature are “meant” for, it should be obvious that this does not tell the whole story about what they can be used for. By Briffa’s logic, a chicken’s thigh is meant to help it stand up and walk. Does that mean we should be wary about eating it, because it wasn’t meant for eating? What about honey, another favourite of health food shops? That was “meant” for bees not humans. As for eggs, well, they were “meant” to be baby animals, not omelettes.

I could go on, of course. But the point is so simple and obvious more examples are not needed. The fact that something originally evolved in nature not as a human food stuff does not mean we shouldn’t eat it. In fact, if we only ate what was unambiguously meant for us to eat, then we’d starve to death as soon as we stopped breast feeding. For breast milk is the only foodstuff that evolved especially for us.

This doesn’t just reveal an interesting fact about nature, but one about reasoning. For in general, nothing about something’s present nature follows by logical necessity from facts about its origins. Consider how the etymology of words, is often interesting but irrelevant to present usage. “Generous”, for example, has its origins in the Latin generosus , which means “of noble birth”. (See the Online Etymology Dictionary.) But that doesn’t mean that to say someone now is generous implies something about their family background. Words change their meanings just as objects change their uses, so knowing an original use or meaning does not tell us what the current use or meaning is.

I say that in general nothing follows about present nature from origins because there are some qualifications to the general rule. For example, Saul Kripke called “rigid designators” those words that name objects and thus have their reference fixed in perpetuity. “Gold” for example, is whatever the stuff called gold happened to be. If Kripke is right, the origins of the word “gold” at least tell us what stuff should now be called gold. But even in this example, our understanding of the nature of gold does change over time and is not constrained by the pre-scientific ideas of those who first named the precious metal.

The phrase “genetic fallacy” was originally coined to describe the confusion between the origins of a belief and its justification. A belief may be justified even if it first emerged unjustified. For instance, the belief that acupuncture can relieve certain pains may be justified even though its origins are with a theory of chi energy flow which is thoroughly unjustified. At the very least, the mere fact that the origins of the belief do not justify it does not show it lacks all justification whatsoever.

Appeals to origins do seem to have a strong rhetorical force. If something’s origins can be traced back the Nazis, the military, agribusiness or imperialism, it instantly becomes less attractive. Similarly, if something has its origins “in nature”, indigenous communities, or social justice movements, it instantly gains some credit. But although the history of an idea or practice may tell us something about its merits today, it need not do so. If something’s origins matter, we need to be shown why they do.