Author Topic: Logical Fallacy: saying we should do something thats already being done  (Read 518 times)

0 Members and 1 Guest are viewing this topic.

Online superdave

  • Stopped Going Outside
  • *******
  • Posts: 4848
  • My name is not dave.
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #15 on: April 27, 2017, 12:10:56 PM »
I taught logic this year and this all stems from a really common misunderstanding about logical statements.

They don't have to be true to be logical. 

I could say that Lebron James is a good basketball player because a genie gave him magical basketball powers.  This is a totally valid logical statement.  It's a false statement because the second half is false, but it's not a logical fallacy because if the second half were true, the first half would also be true.  It's just a lie. 


Online The Latinist

  • Cyber Greasemonkey
  • Technical Administrator
  • Reef Tank Owner
  • *****
  • Posts: 9264
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #16 on: April 27, 2017, 01:33:56 PM »
I taught logic this year and this all stems from a really common misunderstanding about logical statements.

They don't have to be true to be logical. 

I could say that Lebron James is a good basketball player because a genie gave him magical basketball powers.  This is a totally valid logical statement.  It's a false statement because the second half is false, but it's not a logical fallacy because if the second half were true, the first half would also be true.  It's just a lie.

When we were doing our unit on logic, I tried always to include some logically-valid nonsense for my students, because it drove home to them that the formal validity of an argument has nothing to do with its validity.

All dogs are antelopes.  Antelopes only eat antimatter.  Therefore my dog only eats antimatter.
I would like to propose...that...it is undesirable to believe in a proposition when there is no ground whatever for supposing it true. — Bertrand Russell

Offline gmalivuk

  • Well Established
  • *****
  • Posts: 1340
    • http://gmalivuk.livejournal.com
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #17 on: April 27, 2017, 03:22:46 PM »
A non sequitur is also a formal fallacy though
Right, that was the point. Most of the various types and subtypes of informal fallacies are formally just different non sequiturs.

Quote
We were just discussing why *this one in particular* isn't really a fallacy per se.
But pointing out that it's not one of the other formal fallacies doesn't really explain why it isn't a fallacy at all.
I guess I don't know how else to say what I'm saying... when I say "it's not a fallacy" I don't mean that in a "oh yeah, that's basically an okay thing to say" way, I mean that in that "this isn't even wrong" way that only seems to come out when you do something especially damning in a debate. The reasoning is so bad it's not even a fallacy. To have fallacies you have to have premises that could be true, and the statement in the OP doesn't.
I know what you're saying, and I never thought it amounted to "oh yeah, that's basically an okay thing to say".

You said it can't be a fallacy if you know a premise to be false, but it definitely still can be. The situation in the OP isn't a fallacy, but that's not because it has a false premise. "People have used magnets to treat cancer for thousands of years, therefore this magnet will cure my cancer" is fallacious on top of having a false premise.
The world is so exquisite with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there's little good evidence. Far better...is to look death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides.

Offline Johnny Slick

  • "Goddammit, Slick."
  • Poster of Extraordinary Magnitude
  • **********
  • Posts: 11990
  • Fake Ass Skeptic
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #18 on: April 27, 2017, 03:40:52 PM »
OK true.... good point.
Speak what you think now in hard words, and to-morrow speak what to-morrow thinks in hard words again, though it contradict every thing you said to-day.

- Ralph Waldo Emerson

Offline werecow

  • Cryptobovinologist
  • Frequent Poster
  • ******
  • Posts: 3100
  • mooh
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #19 on: April 27, 2017, 06:09:33 PM »
You said it can't be a fallacy if you know a premise to be false, but it definitely still can be. The situation in the OP isn't a fallacy, but that's not because it has a false premise. "People have used magnets to treat cancer for thousands of years, therefore this magnet will cure my cancer" is fallacious on top of having a false premise.

Sure, but it's not fallacious because of the false premise. It's fallacious because it's an argument from antiquity, and it has a false premise on top of that. It would be fallacious even if the premise was true.
Mooohn!

Offline John Albert

  • Off to a Start
  • *
  • Posts: 23
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #20 on: April 28, 2017, 12:14:39 AM »
I taught logic this year and this all stems from a really common misunderstanding about logical statements.

They don't have to be true to be logical. 

I could say that Lebron James is a good basketball player because a genie gave him magical basketball powers.  This is a totally valid logical statement.  It's a false statement because the second half is false, but it's not a logical fallacy because if the second half were true, the first half would also be true.  It's just a lie.

Yep, logic is logic. The logic can be fine, but you can still get a wrong conclusion if one or more of the premises is factually incorrect. 

Like the old computer programmer's adage goes, "garbage in, garbage out."

Offline John Albert

  • Off to a Start
  • *
  • Posts: 23
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #21 on: April 28, 2017, 12:17:52 AM »
You said it can't be a fallacy if you know a premise to be false, but it definitely still can be. The situation in the OP isn't a fallacy, but that's not because it has a false premise. "People have used magnets to treat cancer for thousands of years, therefore this magnet will cure my cancer" is fallacious on top of having a false premise.

Sure, but it's not fallacious because of the false premise. It's fallacious because it's an argument from antiquity, and it has a false premise on top of that. It would be fallacious even if the premise was true.

It's also logically incorrect because treating cancer is not equivalent to curing cancer.

Offline gmalivuk

  • Well Established
  • *****
  • Posts: 1340
    • http://gmalivuk.livejournal.com
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #22 on: April 28, 2017, 08:11:05 AM »
You said it can't be a fallacy if you know a premise to be false, but it definitely still can be. The situation in the OP isn't a fallacy, but that's not because it has a false premise. "People have used magnets to treat cancer for thousands of years, therefore this magnet will cure my cancer" is fallacious on top of having a false premise.

Sure, but it's not fallacious because of the false premise. It's fallacious because it's an argument from antiquity, and it has a false premise on top of that. It would be fallacious even if the premise was true.
Yes, I am aware. That's why I neither said nor implied anything to the contrary.
The world is so exquisite with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there's little good evidence. Far better...is to look death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides.

Offline werecow

  • Cryptobovinologist
  • Frequent Poster
  • ******
  • Posts: 3100
  • mooh
Re: Logical Fallacy: saying we should do something thats already being done
« Reply #23 on: April 28, 2017, 08:44:15 AM »
You said it can't be a fallacy if you know a premise to be false, but it definitely still can be. The situation in the OP isn't a fallacy, but that's not because it has a false premise. "People have used magnets to treat cancer for thousands of years, therefore this magnet will cure my cancer" is fallacious on top of having a false premise.

Sure, but it's not fallacious because of the false premise. It's fallacious because it's an argument from antiquity, and it has a false premise on top of that. It would be fallacious even if the premise was true.
Yes, I am aware. That's why I neither said nor implied anything to the contrary.

I know, I just thought the point should be made a bit more explicit.
Mooohn!

 

personate-rain