Modus Tonens and the Psychological/Rational Tension

There's a wonderful article in the forthcoming edition of Argumentation by our friend Bob Talisse -- he of the weakman arguments. Talisse, along with Scott Aikin, look at the rhetorical use of repeating someone's words back to them with an incredulous tone of voice.

Such a response is fine when it is a genuine reaction of incredulity. It is also fine when one repeats back the words with an incredulous tone in order to call attention to an obvious error -- a trick that teachers use often, allowing conversational space for the errant pupil to realize the mistake and correct it before continuing the discussion. As such, the tone of voice comes with an assertion of power, it establishes a hierarchy. Using that tone of voice says, I really know what I am talking about, you almost do, I'll cut you a break here so that we can keep on talking as if we were equals who both understood this topic, which of course we aren't, but it is only by practicing in this way that you, young grasshopper, can come to learn what is needed to actually understand this topic.

But this pedagogic use is what allows the tone to be misused for undeserved rhetorical gain. By using the tone of voice in a legitimate disagreement, what one does is mislead listeners into thinking that your opponent is cognitively subordinate without giving actual arguments to oppose your interlocutor's position and thereby shift the burden away from yourself -- the burden of undermining the other person's argument -- and putting a new burden on your interlocutor, that of not only defending the position, but also showing that the position is not so absurd that it can be written off immediately. Such fallacious use is called by Aikin and Tallisse "Modus Tonens."

I love informal logic. I love puns. This is sheer joy for me.

Pointing out and delightfully naming the fallacy would be enough, but the interesting part of the discussion is in the pragmatic effects they discuss at the end of the article. They stress that honest discourse already faces the hurdle of group polarization, that is, when people find themselves in groups that agree on an issue, the result often ends up that the group moves towards an extreme of that position. It is a social psychological effect that has been clearly demonstrated. Modus Tonens is just one more way that dissenting voices can be marginalized, undermining the virtues of authentic discourse.

Here is where I want to pick up the discussion because Aikin and Talisse are touching on something that I've talked about with Kerry and Aspazia. Spaz contends that critical thinking may not make for better thinkers, just smarter assholes. It does not cause people to truly think critically, but rather gives them ammunition to defend previously held biases and justify them in more intellectual sounding ways. Scott and Bob bring in the issues that have most interested me, psychology. In some sense, we are fighting against our own wiring in striving to be rational. This is not to say that we cannot be rational, but that there are pre-existing barriers that slant our minds.

As such, should critical thinking be taught without a psychological component? Is being aware of these psychological hurdles a necessary or sufficient condition for avoiding them? Is it worth teaching informal reasoning. if we know there are features of the mind that we are working against or at least is it worth teaching if we don't point those features out?