I don't think this is good advice as stated. If you are showing the symptoms of scurvy then your Vitamin C intake is too low. This model tells you nothing about when your vitamin C intake is too high. But it's still valuable.
It depends on the (possibly implicit) model behind the advice. If the advice is "always take more vitamin C", the it's failing the SC Heuristic because it recognizes no downsides to vitamin C or when you would be taking too much; telling this to a scurvy sufferer is only correct by accident. It would fail to notice that eg too much can cause vitamin C poisoning or (if in the form of fruit juice) obesity or vomiting.
If the model says to take between X and Y units ("but I don't know what's causing the harms outside the range"), then it may be a shallow understanding but it's not failing the SCH, and it avoids a common failure mode.
> it's failing the SC Heuristic because it recognizes no downsides to vitamin C or when you would be taking too much; telling this to a scurvy sufferer is only correct by accident. It would fail to notice that eg too much can cause vitamin C poisoning or (if in the form of fruit juice) obesity or vomiting.
Exactly! And yet for centuries it was nevertheless an extremely valuable model to have (I should have said "lemons" rather than "vitamin c").
Which model and which history? People did historically pass this heuristic because they could articulate a standard for when you're bringing too much lemon.
"Hey -- bring lemons on your ships because it stops scurvy"
'Oh, so why not a ton of lemons? Two tons? Ten tons?'
"Well, to stave off scurvy, you only need x units per sailor per day. Beyond that, it's just expensive deadweight."
In contrast, there are policy advocates who want an X to be higher and yet who haven't met the "tradeoff development threshold". Instead of being able to articulate a model which tells you when X is high enough be a net negative, they will show inability to understand the core challenge: "Strawman, no one's advocating 2X". "That would just be absurd." "I didn't say 2X, I said 1.4X."
It's true that if you posit a scenario in which it's physically impossible to steer far enough right to hit Charybdis, then it will looks successful to have the model "steer as far right of Scylla as you can"; but this isn't the general case, and it wouldn't count as an understanding of tradeoffs.
This comment stuck in my craw a bit, so thanks for provoking some thought. :) Your model isn't modeling Vitamin C consumption, right? It's modeling scurvy. I would guess the model could also tell you about when there are too few scurvy symptoms, which would be "never."
"If I'm going to be late, I should walk faster" isn't modeling velocity — it's modeling punctuality.
>Your model isn't modeling Vitamin C consumption, right? It's modeling scurvy.
I don't see it that way, I see it modeling Vitamin C consumption. To me, your assertion that it's modeling scurvy instead feel contrived in order to fit the top-level comment's princple.
To my mind "your teeth are falling out, you should drink more lemon juice" is the same kind of argument as "our gini coefficient is too high, so we should raise the minimum wage" or "our companies are taking too long to fill positions, so we should allow more immigration".
If someone says "take vitamin C", you don't point blindly at a log chart and thus consume a kilogram of it (which, based on a rat model, probably would kill you).
This is because the practical algorithm for "take Vitamin C" has the grocer, the government, and a team of scientists sign off on the size of a dosage and how many pills are even in a bottle. So while that may not be part of your model, it is most definitely part of the model. The model tells you how much Vitamin C not to take, and so it passes the heuristic.
And without that cap, Vitamin C is unsafe, etc., so the heuristic holds.
It's just an heuristic, something to look for when evaluating a model of the world, not an strict, objective and precise rule.
However, in that example, I'd say that modern medicine certainly has a "too much vitamin C" threshold, and thus might be a sensible model of human vitamin C needs.
I had never seen this idea in writing, but I certainly remember thinking along those lines about retiring age and similar policies.
"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".
