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Tuesday 16 August 2016

Argumentum ad Verecundiam and the Genetic Fallacy


I intended to write a post about paradox, but it's turned out to be considerably more involved than I envisaged, meaning I have lots of diagrams to do, so I thought I'd do a post about the genetic fallacy. This has been on my mind for a while, and I was motivated to get to it after watching an episode of Q&A, an Australian panel show much like Question Time in the UK. In this episode, which I'll pop in at the bottom, one of the panellists,  a newly-elected senator for Queensland, Malcolm Roberts, went head-to-head with my co-citizen of the People's Republic of Mancunia and physicist Professor Brian Cox on anthropogenic climate change. Here's a small cut of the exchange:

Interestingly, when I first saw the name, I was put in mind of another Mancunian, a singer from the '60s born in Blackley, also named Malcolm Roberts.

Anyhoo, there will no doubt be much said about this and, indeed, I see that it's making its way around the news cycle as we speak. I wanted, however, to focus on some specific aspects of what Roberts was saying; argument from authority and 'consensus isn't science'.

In Deduction, Induction, Abduction and Fallacy we covered how logic is used in the sciences, and how to spot some basic fallacies. Among them was a broad class of fallacies known collectively as the 'genetic fallacy'. This fallacy is committed when an argument is dismissed or accepted based only on some characteristic, whether merely perceived or demonstrably extant, of the source of the argument. The most common forms of this fallacy appear as either argumentum ad hominem (argument to the man) or Argumentum ad verecundiam (argument to reverence or authority). Roberts, of course, was accusing Cox of the latter of these with his citation of appeal to authority. His position fails for two clear reasons, and expose a real misunderstanding of how science is conducted, and what it means when a scientist gives advice. Cox attempted to draw him into this by questioning how Roberts thought we should go about attempting to obtain information about the future of the climate, but the format of the programme meant that was doomed to failure from the off, because it doesn't allow the kind of Socratic approach that Cox is fond of, which he quickly realised.

So why is appealing to authority a problem and, more importantly, why does the charge of fallacy not stick in this instance? Let's look at an example that highlights the fallacy.

P1. Richard Dawkins says the universe came from nothing.
P2. Richard Dawkins is a respected scientist.
C. The universe came from nothing.

 There are those who would see no problem with that, though I doubt any of my readers will fail to spot the glaring flaw. Yes, Dawkins is a respected scientist, but his field is not cosmology, it's ethology. It is of no more moment that Dawkins said this (he didn't, by the way) than that Bill O'Really thinks we can't explain the tides.

Let's try another one.

P1. Lawrence Krauss says the universe came from nothing.
P2. Lawrence Krauss is a respected cosmologist.
C. The universe came from nothing.
 Surely we're on firmer ground here?

Frayed knot! Yes, it's true that Lawrence Krauss is a respected cosmologist and, yes, he is an expert in the relevant field. The problem is slightly more subtle here, but it's that Krauss is one cosmologist, so it's of no more moment that Krauss said this (he didn't, by the way) than that Isaac Newton thought that gravity propagated instantaneously.

In another earlier post, I talked at some length about the process that occurs at the end of research. It's known as 'peer-review', and it's among the most important parts of the scientific process. It isn't without problems, but those problems are circumvented by the process itself in the long term.

All scientific hypotheses and theories go through this process. many think that it's confined only to publication, and indeed this is where many of the perceived problems reside. We should, then, distinguish between pre-publication peer-review and the broader process of peer-review because, as some have commented, there are problems with the pre-publication system. There was an investigation conducted by John Bohannon, a correspondent for Science magazine, that makes for interesting reading. These problems are acknowledged but, on the whole, it's been an effective process. However, that's not the end of the process.

The broader process of peer-review actually begins at publication. Publication is merely an indication that the review panel didn't find anything wrong with it. At this point, we can have some confidence in the findings of the study, precisely to the degree that it's passed initial review. Now, experts the world over are looking at the paper, and seeing if it has any implications for their own research, positive or negative. Often, where somebody else's research is very closely related to the paper, they'll try to replicate your results. If it directly contradicts their own research, it will be pulled to pieces. This process is ongoing, and self-correcting. At some point, a paper's contents are going to come hard up against something, just as Newton came hard up against a cosmic speed limit, despite having survived peer-review up the wazoo for several centuries. 

This also provides another valuable lesson about how science is conducted, of course. We understand that positive statements arrived at inductively are tentative. Every time a scientist makes a positive statement, it should be appended with 'the best model we currently have, when applied to the available data, suggests that...'

Where more than one model is empirically equivalent, the same applies, because empirical equivalence means that they make the same predictions about what will be observed.

So, what did Cox actually appeal to in the exchange with Roberts? He certainly cited the public stance of several organisations, all engaged in climate research. Is this an invalid appeal to authority?

No, because of something that Roberts insists isn't science, but which the above should demonstrate readily is not only science, it's good science. Cox didn't only cite various well-respected scientific institutions, he stated that this is what the consensus is, among these organisations collectively. This is the only valid authority in science. When the vast majority of the world's experts in a given field make a positive statement, it's held as a prediction of what the best models tell us, as agreed upon by people who work with and understand the mechanisms and the data. Consensus doesn't tell us what is correct, because that's definitely not science, but consensus among experts tells us that the conclusion is what the available data suggests.

In reality, Cox isn't actually appealing to any authority except the authority of the data. That he cites these organisations at all goes to something that's often not understood.

Throughout this little collection of missives, you'll find liberal sprinklings of the names of well-known and lesser-known people who contributed to the history of science. There are some quotations of Feynman, including the quotation that Roberts so horribly mangled. Am I appealing to them? Not remotely. When, for example, I cite Einstein, I cite him because he's the person responsible for the underlying discoveries, but what I'm actually appealing to is his validated research, research that has undergone the peer-review process, both pre- and post-publication.

So here it is, Malcolm, the empirical evidence that you keep insisting hasn't been presented. 

The world's experts in fields relating to long-term evolution of the environment are in consensus that the data suggest that anthropogenic climate change is real, and that the long-term projections of the models and the data upon which that consensus is based suggest that the future doesn't look good. In short, the consensus of recognised experts in relevant fields is empirical evidence. Let that sink in for a moment.

Ultimately, even if the consensus is wrong, it's deeply irresponsible to ignore it. If there's even a small chance that it's correct, then its incumbent on us to take it seriously, as opposed to dismissing it based on lack of understanding not only of the status of climate science, but a deep ignorance with regard to how science is actually conducted. 

The simple fact is that, as Cox alluded to in the programme, all models predict a 'point of no return'. Climate change is dynamic. It doesn't proceed at fixed rates. There are also things that can affect the future evolution of the system as a result of warming that can accelerate the change, such as the release of methane bound up in permafrost. Methane is around 30 times more efficient as a greenhouse gas than carbon dioxide, and we know there's a huge amount of it tied up in the frozen parts of the world. It can reach a tipping point, beyond which we possibly won't even be able to prevent accelerating, let alone being able to stop or reverse it.

I'm no climatologist, but I understand the physics of climate well enough, and I'm under no doubt whatsoever, having looked at the data, that humans are contributing to the long-term evolution of the climate, in ways we can only assess in broad terms but which, when assessed, point unequivocally to this process, and it's hugely irresponsible to not only ignore consensus, but to actively fight against it.

Ask yourself honestly if this is what you expect from your elected representatives.

Q&A Full episode

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