"Modern medicine" contains a model that includes both criteria for too little and too much vitamin C, but that's not the model that was being referenced. The p

"Modern medicine" contains a model that includes both criteria for too little and too much vitamin C, but that's not the model that was being referenced. The point was that the cited model, "scurvy symptoms => too little vitamin C", is useful (in some situations, very useful, if you aren't in possession of a better model with which this one would agree) while being in violation of the maxim given upstream. I think a much stronger rule - which wouldn't deserve the same catchy name - is that your model should at least be able to say "X is not to low".