Just curious to know if anyone out there has tips for helping students develop the ability to appraise arguments by analogy. Analogies are of course all over in philosophy, especially in ethics, but many of my students struggle to understand how analogies are supposed to support their conclusions and how one might go about criticizing a parcel of analogical reasoning.
Here's one problem in particular that students seem to have. Analogical reasoning procceds by arguing that, because A has feature(s) F and G, and B has feature(s)F, then B has feature G. That's a great simplification of course, but it captures the gist of such reasoning. Many students try to criticize analogical reasoning by pointing out some difference or other between A and B, but the difference they point out doesn't seem to undermine the analogy. (Thomson's abortion article comes to mind here; students are good at pointing out differences between the fetus-mother situation and the violinist-plug in situation, but many of the differences they cite don't do much to undermine what, according to Thomson, is analogous about these two situations). It's as if students fail to appreciate what an analogy is, since they think that one can show an analogy to be weak simply by pointing to any difference at all between the two items. But of course, if there weren't some differences between the analogized items, they would stand in a relation of identity and we wouldn't need to invoke an analogy!
But that's just symptomatic of a larger struggle my students seem to have with figuring out what's going on in analogical reasoning and how to critically engage such reasoning. Any thoughts or tips?