All you Logic students out there, pay attention!
As this year’s Logic and Rhetoric teacher at IHM School, I was this very day on a quest for a broad sampling of enthymemes to show my students so that they will be more familiar with Aristotle’s brilliant little rhetorical device. The quest led me to this page, where the author set about to contrast enthymemes, which are “rhetorical syllogisms,” from their more formal cousins in the liberal art of Logic.
So, under the heading, “Enthymeme vs. Syllogism” (a clue to the atrocity that follows: are they really opposed?), we find the following given as a model syllogism:
- All reptiles are cold-blooded animals. (Major premise)
- A lizard is a cold-blooded animal. (Minor premise)
- Therefore, a lizard is a reptile. (Conclusion)
I was reading quickly because I wanted to get to the object of my quest — the part on enthymemes, that is — but I stopped in my tracks here. Whoa, Nelly! Clearly, we have a problem. I carefully reread the syllogism and found that it violated one of the seven rules governing categorical syllogisms. There was no explanation on this educational site that what they were proposing as a sample syllogism was, in fact, an invalid syllogism.
Question to the reader: Which of the seven rules does this syllogism violate? Please place your reply in the comments section, below.
I was gratified that when I proposed this question to my class, a Junior named Mark did not take long to figure out the correct answer, which he stated with great confidence. A surge of pedagogical joy filled my soul.
If you have no idea what any of this means, maybe you would do well to take Brother Francis’ Philosophy Course.
