It's still crazy even if a bunch of people like it.

With Mitt Romney's selection of Paul Ryan as his Vice-Presidential candidate, there has been a great deal of discussion about Ryan's economic plan with many in the media suggesting that Ryan was a great choice because of his knowledge of economics (he has a BA) and the popularity among Republicans of his comprehensive budget plan introduced into Congress earlier this year. One such media figure is Joe Nocera who, in an op-ed in the New York Times today provides an excellent example of an Ad Populum. He writes:

Simply dismissing these ideas [Ryan's budget plan] as crazy is a mistake. There are many people in the country who agree with Ryan — as they showed two years ago, when they elected 87 Republican freshmen, many of them Tea Party-backed political novices, to the House of Representatives, who went to Washington vowing to shrink the federal government. Although they have had only marginal success so far, it hasn’t been for lack of trying. Their desperate urgency gave us, among other things, the debt-ceiling crisis, in which they risked putting the government in default.

Essentially, Nocera is arguing that we should take Ryan's plan seriously because many people agree with and like the plan. In fact, as many respectable economists have noted, Ryan's plan is junk combined with wishful thinking designed solely to make the rich even richer at the expense of everyone else. As Paul Krugman argues:

Look, Ryan hasn’t “crunched the numbers”; he has just scribbled some stuff down, without checking at all to see if it makes sense. He asserts that he can cut taxes without net loss of revenue by closing unspecified loopholes; he asserts that he can cut discretionary spending to levels not seen since Calvin Coolidge, without saying how; he asserts that he can convert Medicare to a voucher system, with much lower spending than now projected, without even a hint of how this is supposed to work. This is just a fantasy, not a serious policy proposal.

For Nocera to argue that we should take the plan seriously because many people like it is an excellent example of an ad populum. Given the complexities of economics and the lies and distortions people like Ryan are willing to spew, the fact that many people like Ryan's plan is only evidence of the wrongness of many people, and provides no justification for taking Ryan's budget proposals seriously.

h/t to Tristero

Reality is not a democracy

In a rather bizarre article trying to argue that plants aren't alive (yes, really), Henry Morris III, CEO of The Institute for Creation Research provides a very nice example of an Ad Populum. An ad populum is an appeal to popularity in which one argues that because a certain belief is widely held or popular it must be true. That this kind of reasoning is fallacious should be obvious: just because a bunch of people believe something, doesn't make it true. Reality is not a democracy. Here is the ad populum:

If that were the only battle to fight, the scientific accuracy of the creationist model would be rather easy to demonstrate. In spite of the generations-long effort of the academic world to foist evolutionary naturalism on the world, 46 percent of the U.S. population still believes that “God created human beings in their present form at one time within the last 10,000 years” (Gallup poll released June 1, 2012). Intuitively and observationally, people “know” that plants and animals are not the same and that human beings are vastly different from everything else on the planet.

There are a number of fallacies in this passage besides the ad populum, but let's deal with that first. Here, Norris is trying to argue to that because many (though less than half) Americans don't believe in evolution this is somehow evidence of the falsity of that theory. Again, just because many people believe something, that doesn't make it true. In this case, it seems clear that 46% of Americans are just wrong.

Furthermore, this fact about popular opinion doesn't actually support Morris' thesis that plants are not alive. Even if 46% of Americans don't believe in evolution, I imagine that if you polled these people they would all think that plants are alive. The opinion of people about the truth or falsity of evolution tells us nothing about their opinion on whether or not plants are alive. This is a good example of a non sequitur.

Lastly, we can see a good example of a straw man in the last sentence. I (and I imagine most evolutionary biologists) would certainly agree that it is obvious that plants and humans are different. Just look at them.

Maybe not this guy.

However, these radical differences don't tell us anything about common descent. In fact, evolutionary theory does a very good job of explaining how the diversity of life we observe on our planet all descended from a common ancestor. To claim otherwise is to misrepresent the claims of proponents of evolution.

h/t to Pharyngula

Same-Sex Marriage, Bestialty and Slippery Slopes

A Slippery Slope is a fallacy in which one argues that change in one direction will inevitable lead to further disastrous change in the same direction. The idea here being that if we start down some slope of change we will inevitable find ourselves sliding all the way to the bottom. One of the more common versions of the slippery slope that one finds in contemporary American politics (though less and less as views change and evolve) is the claim that legalizing marriage between two men or two women will inevitably lead to the legalization of marriage between a man and an animal or between an adult and a child. For example, in 2008 then presidential candidate Mike Huckabee said:

Marriage has historically, as long as there’s been human history, meant a man and a woman in a relationship for life. Once we change that definition, then where does it go from there?
Well, I don’t think that’s a radical view to say we’re going to affirm marriage. I think the radical view is to say that we’re going to change the definition of marriage so that it can mean two men, two women, a man and three women, a man and a child, a man and animal. Again, once we change the definition, the door is open to change it again. I think the radical position is to make a change in what’s been historic.

This is a pretty clear example of the slippery slope argument. Just because we modify the definition of marriage to include two men or two women does not imply that we will then necessarily broaden the definition to include pedophilia or bestiality or polygamy (though, I should note the argument for polygamy is much more reasonable than for the other two). In fact, if one thinks a little bit about what marriage actually is, it will become clear that these two sorts of relationships would be impossible to legalize. In particular, it must be noted that marriage is primarily a contractual relationship. This means that in order for such a relationship to occur both parties must be able to enter into a contract. And this is simply not possible for an animal or a child.

In addition, the first part of this passage is a good example of the Ad Populum or Appeal to Tradition in that Huckabee is arguing that because marriage between a man and a woman is traditional it would be wrong to change it.