The Wikipedia quote is unsourced. (My main source of knowledge about Brown-Sequard's involvement is Stipp's book and a few other minor sources none of which mention the derisive elixir claim.)

I find myself confused as to how anyone could legitimately, upon reading what you claim to have read, hold forth the stance you claim to hold. I find it to be internally and externally inconsistent with the axiomatic assumption of rational honesty.

Is this intended as a personal attack or is there some other intention? This looks a bit like a series of boo lights apparently directed at me. But I'm already convinced that you and I have sufficiently different communication styles that I may be simply misreading this. What do you mean by "axiomatic assumptions of rational honesty" and how do you think what I have said is "internally" and "externally" inconsistent? Trying to interpret this, I'm getting something like "I don't think an individual who is trying to be rational and have an intellectually honest dialogue could distort sources the way you are doing." Is that what you mean to say? I can sort of see how you might get that if you thought I was using the Wikipedia article as a source. I just linked to it because although he was a major scientist around 1900, he's fairly obscure now. I didn't read it. Does that possibly explain the confusion here?

Average human lifespan (with medical care) is roughly analogous to the average human lifespan of the elephant, so that's not exceptional. But I didn't limit my statement to mammals but to endothermal.

Right, and I limited mine to mammals since it is a lot easier to look in that context, since the metabolisms are pretty different. Note by the way that your example of an elephant actually shows my point pretty well: elephants are an order of magnitude larger than humans yet humans have maximal lifespans slightly exceeding that of an elephant. The oldest elephants have been a bit over 80 years old. That's in captivity with good veterinary care. But even without modern medical care humans have exceeded 110 years (albeit very rarely). There are two obvious issues with this (humans pay a lot more attention to old humans than old elephants, and we have a much larger supply of well-documented humans than we do of well-documented elephants), so it wouldn't be unreasonable to suspect that with a large enough sample the elephants' maximal age would look closer to the human maximal age. But then there's the whole order of magnitude larger thing. It does seem like great apes and humans in particular are already doing something else that has extended our maximal lifespan.

Attempts to project from the past into the future are doomed to failure when they do not take into account the present Yes, which is why I asked for explicit descriptions of what data about the present other than there being a lot of people working on these issues that you were using. So what judgments are being made about our current knowledge of biochem that go into your conclusion?

Medicine is not like math. It is far more like engineering.

Sure. I'd agree with that. So let's look at engineering examples where lots of resources have gone into things. Fusion power would be a really good example. There have been billions of dollars put into fusion power research in the last fifty years (see e.g. this for data on but one source of funding from the US government that has given billions of dollars to fusion research). Famously, fusion power is always about twenty-five years away. Sometimes problems are just tough. Sometimes the wall isn't as sticky as you think it is.

... Increased knowledge in one field necessarily alters or amplifies the impact of knowledge in another. Are you familiar with the concept of scientific convergence?

Yes. But I still don't see how this is in any way results in a conclusion that the statement in question "is asinine". So I'm still confused.

The hypothesis was "maybe humans already have calorie-restricted metabolisms". This has been falsified. This is not even remotely questionable. It's false. We've got proof on the matter.

Please don't tell me what my hypothesis was. The comment you were responding to was me raising the possibility that:

It could turn out that humans already do something to their cells that mimics most of the effects of reservatrol.

Notice that this statement says nothing at all about caloric restriction. The rest of your next paragraph is similarly irrelevant.

This is juvenile. There isn't a single thing on the planet that everyone consumes besides air and probably water. After that, it's isolation and elimination from diets. And that's how science is done. C'mon now -- let's try to restrict our hypotheticals to things that are at least remotely plausible within the current world-line?

I don't see what's juvenile about this, and it would be slightly appreciated if you would make arguments that didn't involve unnecessary personal attacks. Your observation about what is commonly consumed is quite accurate. So, if there's something common in say the Western diet that reduces the effects of reservatrol or some similar compound, we might not even notice until we notice that the anti-aging compound is having much less of an effect than anticipated. And then you'd need to go and test those compounds. That sort of problem falls easily in the "remotely plausible" line of failures or in the "conceivable" world-lines you mentioned earlier.

It is a strong claim which emerges from a large series of independent small claims each with high probability individually. There is a saying; "three ifs ruin a plan". You'd have to have far more than three "ifs" for my claim to turn out to be wrong.

That's fine if your claim is "this is likely to work" or even "this is very likely to work." But you've claimed that there's no conceivable world-line where this isn't working in fifty years and there hasn't been societal collapse or something similar preventing the research.

At this point, I have to wonder if we are running into problems of inferential distance. This is why I tried to ask you to make your earlier chain of logic explicit. Reducing it to premises like the non-supernatural nature of biology and then saying etc. is not helpful for bridging inferential distance gaps.