When I fight authority, reality always wins

The arguments from authority and popularity are slippery, tricksy little fallacies. Sure, they seems simple enough, but as I’ve recently discovered, they’re a bit more complicated than they look at first.

The most basic, stripped-down Argument from Authority looks like this: X is true because A says it is true, where X is some proposition and A is a figure of some authority (though not necessarily in the field which governs X). I doubt you’ll ever see it stated so simply, because on its face it is patently absurd. Despite what The Secret or What the Bleep might tell you, we cannot make things true simply by saying them. No, usually it’ll be “X is true, A says so!” or “A believes in X, why don’t you?” It’s all the same, just dressed up a bit.

And, regardless of what a Mage: The Ascension handbook might tell you, reality is not democratic, and is not created by what large numbers of people believe. So, when you see someone saying “X is true because lots of people say it is true,” you ought immediately to think “only if I’m holding a handful of ten-sided dice.”

But the problem with these arguments is that sometimes, they look right. I’ve had a bit of impromptu sparring with Mr. Kirk of the God/No God blog on the subject of Global Warming, and how the primary argument for it appears to be “it’s true because all scientists say so.” Now, I know that’s not the primary argument for it (the primary argument is “because it’s happening and we can measure it, and CO₂ levels are building up to cause a Greenhouse Effect,” so far as I’m aware) but I can see where it might look like that to the laity. There are many (I might even say ‘most’) cases where both parts of the argument–“X is true” and “A/lots of people say that X is true”–are true. The problem is the “because,” which misrepresents the causal relationship.

And after a bit of thinking, I figured out the root of the problem: these arguments are conversions of true statements. But not all true statements have true converse statements.

So, let’s start with a true statement: Lots of people say the sky is blue because the sky is blue. Both the red and green parts of the statement is true, and the green statement is the cause of the red one, so the whole statement is true. Now, flip the red and green portions (forming the converse of the statement), and you get The sky is blue because lots of people say the sky is blue. Both the red and green portions are true, but the cause/effect relationship is screwed up, so the whole statement is false, and is an argument from popularity besides.

See, when something is verifiably true, lots of people and authorities will claim that it is true. Everyone says that the sky is blue because the sky is blue (except when it isn’t, but we’re talking generally). Scientists say that atoms exist because the evidence heavily suggests that atoms exist. The problem is that people and authorities often make claims which are not verifiably true, or which are demonstrably false, and so cannot be considered reliable sources in all cases.

So, what of Global Warming? I know I’m not the only one who has said “all reliable scientists say that it’s happening, and that human activity is contributing to it.” Isn’t that an argument from authority?

Well, not exactly. If I were saying “it’s happening because all scientists say so,” then sure, that’s an argument from authority. But I’m not saying it’s happening because all reliable scientists say so, I’m saying you should believe it because all reliable scientists say so. It’s not much of a difference, but it’s a significant one, because it doesn’t make a causal statement. I should just make explicit the causal statement that remains: “all reliable scientists say so because the evidence says so.”

See, in evidence-based fields like science, all claims have to be supported by evidence. If you make a scientific claim that isn’t supported by evidence, you’re going to get called on it by people who know what the evidence suggests. Since evidence is the same no matter who looks at it, most people in a given field will come to the same conclusions, until new evidence forces them to change their conclusions. So, when the majority of scientists in a given field support a conclusion in that same field, chances are the evidence supports it as well.

Now, there are scientists claiming that Global Warming isn’t happening (fewer of them, now), or that while it is happening it isn’t being caused by human activity. RealClimate has a list of answers to common contrarian claims, and lower on the page a list of links that addresses Mr. Kirk’s solar suggestion, but for a moment, let’s assume that these latter scientists are correct, and that humans are not the main cause of global warming. Now, there are a few things of which we can be relatively certain, based on the evidence and the models:

1. Carbon dioxide and other ‘greenhouse gases’ act as a natural atmospheric insulator, trapping heat from the sun so it remains close to the Earth’s surface and is not just radiated back out into space.
2. The Earth’s temperature is rising at an unprecedented rate.
3. Carbon dioxide levels in the atmosphere are very high.
4. Humans, through combustion, release Carbon Dioxide into the atmosphere which would not naturally be there.

So, again, let’s assume that Global Warming is mostly caused by some other condition. Shouldn’t we still try to curb our CO₂ emissions? We know that excess carbon dioxide has the possibility of increasing the surface temperature; even if it isn’t the reason for the observed climate change, shouldn’t we do what we can so that we don’t exacerbate it? We have the following options:

1. GW is not caused by humans, and we do not change our actions. Human-generated carbon dioxide does not exacerbate the situation.
2. GW is not caused by humans, and we do not change our actions. Human-generated carbon dioxide does exacerbate the situation.
3. GW is not caused by humans, and we do change our actions, preventing any possible exacerbation.
4. GW is caused by humans, and we do not change our actions. Human-generated carbon dioxide does cause and exacerbate the situation.
5. GW is caused by humans, and we do change our actions, preventing any possible exacerbation.

If we don’t change our actions, we have a 20% chance of not making things worse. Changing our actions means not only do we eliminate the chances of making things worse (at least as far as CO₂ emissions are concerned) and a chance of making things better, if in fact we’re causing the climate change.

And all the reliable information, and simple logic, suggests that we are. I mean, honestly, we know that carbon dioxide acts as the planet’s thermal insulator, and we know that we’ve been pumping extra CO₂ into the atmosphere for the last hundred and fifty years, all over the world. Saying that all that would have no effect, when the effects that it’s predicted to have are occurring, seems disingenuous at best.