you're so fallacious
6/1/05 13:18![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
schmericaComing up on three years since I took Informal Logic at SRC, I was complaining to ![[livejournal.com profile]](https://www.dreamwidth.org/img/external/lj-userinfo.gif)
dsudis about how I seem to be forgetting all the names of various things. Like, I can still see where the fallacies pop up, and what's valid and what isn't, but I can't remember why, or what it's called.
So, then, of course, I went to look them up and remember what each one was called. And then I made up stupid little examples to show Dira, and she very kindly pretended to care even a little tiny bit.
So. I present to you all My Completely Pointless Examples of Logical Forms, Illustrated By Due South Slash. Enjoy.
Denying the Antecedent
If you are a Mountie, then you are hot.
Ray is not a Mountie.
Therefore, Ray is not hot.
FALLACY.
Affirming the Consequent
If you are Ray, then you are hot.
Fraser is hot.
Therefore, Fraser is Ray.
FALLACY.
Modus Tollens
If you are Fraser, then you are a Mountie.
Ray is not a Mountie.
Therefore, Ray is not Fraser.
VALID, YAY!!!
Modus Ponens
If Ray is really hot, then Fraser will want to have sex with him.
Ray is really hot.
Therefore, Fraser wants to have sex with him.
VALID, YAY!!!
*cough* Oddly, considering our normal conversations, this is actually not very dorky for Dira and me. Less so than our linguistic squee, at least.
dsudis about how I seem to be forgetting all the names of various things. Like, I can still see where the fallacies pop up, and what's valid and what isn't, but I can't remember why, or what it's called.So, then, of course, I went to look them up and remember what each one was called. And then I made up stupid little examples to show Dira, and she very kindly pretended to care even a little tiny bit.
So. I present to you all My Completely Pointless Examples of Logical Forms, Illustrated By Due South Slash. Enjoy.
Denying the Antecedent
If you are a Mountie, then you are hot.
Ray is not a Mountie.
Therefore, Ray is not hot.
FALLACY.
Affirming the Consequent
If you are Ray, then you are hot.
Fraser is hot.
Therefore, Fraser is Ray.
FALLACY.
Modus Tollens
If you are Fraser, then you are a Mountie.
Ray is not a Mountie.
Therefore, Ray is not Fraser.
VALID, YAY!!!
Modus Ponens
If Ray is really hot, then Fraser will want to have sex with him.
Ray is really hot.
Therefore, Fraser wants to have sex with him.
VALID, YAY!!!
*cough* Oddly, considering our normal conversations, this is actually not very dorky for Dira and me. Less so than our linguistic squee, at least.
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
(no subject)
6/1/05 22:44 (UTC)Therefore,
...er, I hope I did that right. Is Affirming the Antecedent both valid and true?
(no subject)
6/1/05 22:53 (UTC)The truth thing is complicated, though, yeah. Valid just means that if the premises are true, then the conclusion must be true. So using the modus ponens -- if p, then q; p; therefore q -- the argument will always be valid.
Thus you can say:
If Ray and Fraser have sex, then I win a million dollars.
Ray and Fraser have sex.
Therefore, I win a million dollars.
So that is a valid argument, but not a sound one, because the premises are not true to begin with.
...Yes.