Logic Lesson 4: Rules of Inference for Dilemmas

Part of a series on logic, this video covers the rules of Constructive Dilemma and Destructive Dilemma, thereby completing a three-video overview of the Rules of Inference. It recaps the other rules, covers these two in detail, shows their relationship to Modus Ponens and Modus Tollens, demonstrates the validity of Constructive Dilemma with a truth table, and covers three ways of responding to dilemmas: Going Between the Horns of a Dilemma, Grabbing the Horns of a Dilemma, and constructing a Counterdilemma.

For a written summary of this video, go to my blog page on this video at:

This video is part of a series on symbolic logic. For a more in-depth look at the other rules of inference, check out the earlier videos in this playlist:

[-astrangerontheinternet]

Thank you for this. It’s very helpful in these times when parents are all home schooling.

[jamesz]

Thanks for posting this video. I helped me out a lot for a test I have to take this week.

[almejia]

Thank you for the videos, they have been a big help!


Can you make videos on the rest of the rules of inference?

[KendrixTermina]

Awesome. Your videos show that you're quite the educated individual, but instead of being stuckup about it, you try to make others *see* and improve their lives. I think your explanation with all the examples were quite well done.
Little nitpick, tough: While not eating meat might decrease the risks of certain forms of cancer, it also increases the risks for other kind of cancer. (For example, the colon cancer risk rises significantly. Yes, even tough *too much* meat also increases it) ;)

[VjSinh]

Correct me if I am wrong, at 02:57 under Dilemmas/ constructive dilemma, shouldn't it be P or R instead of P or Q?

[fortheloveofwisdom]

@sdebose54 I started it shortly before 13:30 and watched it all the way to the end. It might be a bug with whatever browser you were using. If you still can't get past 13:30, try watching it on a different browser or with a different operating system. If you are consistently having trouble with a particular browser, let me know.

[sdebose]

This is a great video but, the video stops at 13:30 from a 21 minutes and fifty five seconds. What happen?