Informal Logic

Argumentum Ad Hominem: Bias and the Case Against Industry-Funded Research

Here are some contentious questions guaranteed to start an argument:

  • Do oil companies fund research that is more likely to minimize the threat of climate change or downplay the risks of fracking?
  • Do tobacco companies fund research that is more likely to minimize the health risks of smoking?
  • Do pharmaceutical companies fund research that is more likely to minimize the health risks of a novel drug?

For some people, these are rhetorical questions. Their intuition in such cases cries “yes!” Do maxims like “follow the money” and “don’t bite the hand that feeds you” spring to mind as relevant under these circumstances? For others, these questions are tantamount to ad hominem fallacies driven by a knee-jerk anti-corporatist mentality. Who is right?

Argumentum Ad Hominem

For many years, any ad… Continue reading

Climate Change Skepticism and Argumentum Ad Baculum

Consider this recent blog post by Andy Borowitz in The New Yorker (Jan. 6, 2014), “Polar Vortex Causes Hundreds of Injuries as People Making Snide Remarks About Climate Change Are Punched in Face.” Ask yourself whether it is an example of argumentum ad baculum.

MINNEAPOLIS (The Borowitz Report)—The so-called polar vortex caused hundreds of injuries across the Midwest today, as people who said “so much for global warming” and similar comments were punched in the face.

Authorities in several states said that residents who had made ignorant comments erroneously citing the brutally cold temperatures as proof that climate change did not exist were reporting a sharp increase in injuries to the face and head regions.

In an emergency room in St. Paul, Harland Dorrinson, forty-one, was waiting to be treated… Continue reading

Formally Valid Non Sequiturs?

One common conception identifies logical fallacies with arguments “that seem valid, but are not.” This definition is difficult to sustain however, because there are arguments so obviously fallacious that they would probably would not trick anyone with their “seeming validity.” While there are fallacious arguments that are invalid, there are examples of fallacious arguments that are valid, while others are even sound. In order to notice these examples, and identify their logical shortcomings, we need to use the tools of informal logic, not being content to let formal validity or formal fallaciousness decide the ultimate logical disposition of a given argument.

Formal Fallacies – Fallacies of Relevance?

What is wrong with this argument?

(P1) All collies are animals.
(P2) All dogs are animals.
(C)  Therefore, all collies are… Continue reading

The Critical Thinking Left

We tend to think of the methods and attitudes of critical thinking as politically neutral. We suppose that critical thinking doesn’t discriminate; any appeal to tradition or authority is subject to critical challenge, regardless of what tradition or whose authority is in question. Nevertheless, there is a faction within the critical thinking “movement” that does have some affinity with left-wing politics. I call this faction the “critical thinking left,” to distinguish its theoretical slant from its political commitments.* Its prevalence among educational reformers helps explain the Texas GOP’s doubts about the teaching of critical thinking.

Identifying Assumptions; Imagining Alternatives

Critical thinkers universally acknowledge the importance of identifying and challenging assumptions, and of imagining and exploring alternatives. Clearly, assumption-hunting has an important role to play, and I include it as one of the… Continue reading

Are Critical Thinking Skills Transferable?

In my post of 5/5/2012, I referred to a discussion of a 2010 AMA Critical Skills Survey in which executives were asked several questions about employee’s competencies at “21st Century skills.” The survey was sponsored in part by P21, an educational reform organization leading an effort to integrate “the Four Cs” into the K-12 system via curriculum reform. The P21 movement has vocal critics over at Common Core, among them E. D. Hirsch, Jr., author of The Schools We Need and Why We Don’t Have Them. Their objections are based on a skeptical view of the transferability of critical thinking skills across subject domains (which they ascribe to P21). I think they overstate the case.

The crux of the argument is articulated by Hirsch as follows:… Continue reading

SOPA, PIPA and the Slippery Slope

It’s not often that someone offering a bad argument to support their position on an issue actually names the logical fallacy undermining the soundness of their reasoning in their statement of the argument itself. But we were treated to that today!

Whatever your own feelings about the draft legislation of SOPA/PIPA, here is a great example of how not to argue against today’s (1/18/2012) Wikipedia “blackout”:

My main concern is that it puts the organization in the role of advocacy, and that’s a slippery slope,” said editor Robert Lawton, a Michigan computer consultant who would prefer that the encyclopedia stick to being a neutral repository of knowledge. “Before we know it, we’re blacked out because we want to save the whales.” [Link]

The problem with… Continue reading