Monsters of Logic
It’s that time of the semester again: time to tell logic students the bad news that material conditionals are false only when they have true antecedents and false consequents.
I’m always looking for new ways to take the sting out of the false antecedent cases. Poking around the internet yielded some nice resources.
I especially liked this survey of methods of teaching material conditionals: A Comparison of Techniques for Introducing Material Implication
See also:
Conditional Statements and Material Implication
and
Material Implication Revisited
September 17th, 2007 at 8:07 am
Bah, I’m with QUIN82 on that one! “The choice of declaring a conditional to be true whenever the antecedent is false is arbitrary.”
Also, G.T. Kneebone is the best name ever. He should’ve been a blues singer.
September 17th, 2007 at 8:56 am
I’m with Q on 99.9% of everything, but I like to not let the “logic is make-believe” cat out of the bag until slightly later in the semester.
Before you give the best name medal to Kneebone, you should be aware of a guy Ray and I saw on the news the other night: Chubby Seebrane.
September 18th, 2007 at 10:30 am
You’re right, that’s even better. But what about Adrian van Hooydonk?
September 18th, 2007 at 12:21 pm
Hmm. I think I still pledge allegiance to “Chubby Seebrane”.
October 3rd, 2007 at 2:09 pm
[…] commento | Stampa Rubrica: Pensieri inutili| Argomenti: Implicazione materiale, Logica Grazie al Brain Hammer ho trovato un interessante articolo di Matthew C. Clarke sulle diverse tecniche per spiegare […]
October 15th, 2007 at 4:12 pm
Pete, not sure if this is what you have in mind, but to show that F–>F conditionals are true, I use examples like, She said “I’ll go on a date with you … when hell freezes over” or “If Eddy’s a good teacher, then pigs can fly” or “If Zell Miller is a democrat, then Jesse Jackson is a republican.” To show that F–>T conditionals are true, it’s best to just point out that they *can* be true. “If you fail this test, you will fail the course” does not imply that if you pass the test you will pass the course.
October 22nd, 2007 at 3:41 am
Thanks, Eddy. I especially like date one.