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 Ontario Society for the Study of Argumentation (OSSA) is holding its annual conference at the University of Windsor (Ontario, Canada) on May 22-25, 2013. This year, the theme of the conference is “Virtues of Argumentation.”
Keynote speakers include Daniel H. Cohen, Marianne Doury and G. Thomas Goodnight. Other speakers include Anthony Blair, Frans van Eemeren, Robert Ennis, James Freeman, Trudy Govier, Leo Groarke, Donald Hatcher, Ralph Johnson, Robert Pinto, Robert Rowland, Harvey Siegel, Jean Wagemans, Douglas Walton, and many other thought leaders in the field from around the globe.
I have been invited to provide commentary on a paper by Dmitri Bokmelder on the subject of “Cognitive biases and logical fallacies.” Here is the abstract of his paper:
Cognitive biases identified in psychology are indications of imperfect reasonableness of… Continue reading
According to the Website indeed.com, the proportion of posted job descriptions calling for “critical thinking” has increased 300% over the past seven years. This is consistent with other observations that critical thinking in the workplace continues to increase in significance.
In October, I had the pleasure of attending a symposium on the “Argumentative Theory of Reasoning” at which the keynote speaker was psychologist Hugo Mercier, co-author with Dan Sperber of a landmark paper published in Behavioral and Brain Sciences in 2011 entitled “Why do humans reason? Arguments for an argumentative theory.” Mercier’s presentation was organized by the Centre for Research in Reasoning, Argumentation and Rhetoric at the University of Windsor (Ontario). In this post, I’ll summarize in my own words the key points and lines of argument in Mercier’s presentation. (More details can be found in the original Sperber-Mercier paper, available online).
What is Reasoning?
According to Mercier, reasoning is the cognitive process in which reasons are used to weigh decisions and justify beliefs. As such, reasoning is not… Continue reading
Human beings have the capacity to reason. But we often don’t do it nearly as well as we could. We all make choices in our lives that add up to socially suboptimal outcomes. Could the government do better making some choices for us? Should it?
Consider the libertarian argument for the claim that a just society is one in which individual rights are rigorously and consistently protected by law. The key premise in this argument is that these rights — i.e., to life, liberty and property — are of paramount importance because each individual person requires these as conditions for the exercise of rationality. But if human beings don’t in fact exercise this capacity as they might (and perhaps as they should) would this ensure that the case for… Continue reading
In common usage, “phobia” connotes fear. Nevertheless, the term “Islamophobe” can legitimately be applied to people with a prejudicial hatred of Muslims, too. On the other hand, when the term is used to characterize someone with informed critical objections to the substance of Islamic doctrine, it is a smear. The proper term to describe the informed critic is “anti-Islamist.”
Phobias as Psychiatric Disorders
A perceived danger will provoke a “flight or fight” response in any animal, human beings included. When a person’s perception routinely misrepresents the actual severity of a type of threat, this might indicate the presence of a “phobia.” A fear of spiders, for example, is arachnophobia; a fear of heights is acrophobia. In the most common psychiatric sense of the term, a phobia is an… Continue reading
A published review of 117 empirical studies assessing the impact of critical thinking instruction on critical thinking (CT) skills and dispositions confirms my suspicions: some instruction has a powerful positive effect and some instruction has no effect at all. Overall, these results support the view that, on balance, there is a measurable positive effect. And there are tentative indications of what kind of instruction fosters the most marked improvements in critical thinking.
In their paper “Instructional Interventions Affecting Critical Thinking Skills and Dispositions: A Stage 1 Meta-Analysis,” (Review of Educational Research 78:4, December 2008), Philip Abrami and six Canadian co-authors attempt to derive measurements of the effect of pedagogical “interventions” intended to improve critical thinking.
In their meta-analysis, Abrami et al. used Ennis’ taxonomy to divide the studies into… Continue reading
John Rawls’ A Theory of Justice introduced a memorable thought experiment related to the nature of a just society. Rawls asked what principles would we chose to regulate the basic structure of society if we had to chose those them from behind a “veil of ignorance” as to our own position in that society. One of those was the “difference principle,” that is, that economic (and social) inequalities, to the extent that they exist, must be relatively advantageous to the most unfortunate members of society vs. a strict egalitarian distribution of wealth and income.
In a recent article (“How Americans view wealth and inequality“), behavioral economist Dan Ariely reviews data from a survey in which Americans were asked how much inequality there should be in… Continue reading
One of the goals of effective thinking advocacy is to help people relieve themselves of some of their kooky notions. This is a goal that is shared with those in the skeptic movement, who think that spreading public understanding of science will help people reject pseudoscience and reach conclusions based on reason and evidence. It seems plausible enough: teach people about evolution, for example, and they should reach the conclusion that neither man nor beast really came from the mythical Garden of Eden.
Wouldn’t we expect that people exposed to some university-level coursework in science will be better equipped to evaluate scientific claims critically, and distinguish genuine scientific knowledge from pseudoscience and generic hokum? It turns out that it doesn’t, according to a new paper from Massimo Pigliucci. For rational… Continue reading
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