Catholicism and Persuading God

Originally posted by bbarr
It doesn't matter if you assume that a proposition is true. If you assume that P is true, and then go on to derive both P and ~P on the same line of a proof, you are thereby licensed to infer ~P. This would still be (literally) a textbook example of proof by contradiction.

Giving him the maximum benefit of the doubt, it appears he used a Reductio ad Absurdum, not a proof by contradiction.

http://www.iep.utm.edu/r/reductio.htm

Originally posted by no1marauder
It appears he used a Reductio ad Absurdum, not a proof by contradiction.

Hilarious.

Why did you lie when I asked you if you could recognize a proof by contradiction when you encountered one?

Originally posted by no1marauder
Giving him the maximum benefit of the doubt, it appears he used a Reductio ad Absurdum, not a proof by contradiction.

http://www.iep.utm.edu/r/reductio.htm

Those are two different names for the same thing.

No1, why don't you just withdraw all of your objections, and we can all forget that this ever happened. It's frankly getting a little embarrassing for me to continue to humiliate a stubborn old man.

Originally posted by DoctorScribbles
LMAO! You are one confused old man.

What is the proposition in question that you assert I assumed to be true?

Don't you realize assuming one proposition is true is equivalent to assuming that its negation is false? I suggest you carefully label all of the propositions in question, and you will see that, wonder of all wonders, it fits the mold as described in your reference.

You're truly absurd. Read the second question and the first two words of the third question if you are confused as to what the proposition you assumed to be true in the third question is.

Originally posted by no1marauder
You're truly absurd. Read the second question and the first two words of the third question if you are confused as to what the proposition you assumed to be true in the third question is.

You are a real masochist. Do you really want to continue this battle? What do you estimate are your chances of coming out of it not looking like a complete fool, much less a winner?

Originally posted by bbarr
Those are two different names for the same thing.

Professor Wolfram doesn't think so. I gave the link to his definition of proof by contradiction earlier. Here's the one to Reductio ad Absurdum:
http://mathworld.wolfram.com/ReductioadAbsurdum.html

Originally posted by DoctorScribbles
You are a real masochist. Do you really want to continue this battle? What do you estimate are your chances of coming out of it not looking like a complete fool, much less a winner?

You have a big mouth and do a lot of bluffing. That intimidates some people I'm sure. Not me.

Your first post was a logical mess as is generally true of your attacks on the RCC. The fact remains that a question can't be answered "true" if it is reliant on a premise that is conceded to be "false".

Originally posted by DoctorScribbles
Hilarious.

Why did you lie when I asked you if you could recognize a proof by contradiction when you encountered one?

What part of the definition given didn't you understand?

Originally posted by no1marauder
You have a big mouth and do a lot of bluffing.

Like when I threw out a random big term like "proof by contradiction" and got lucky that it turned out to mean something so serendipitously beneficial to my position?

Originally posted by DoctorScribbles
Like when I threw out a random big term like "proof by contradiction" and got lucky that it turned out to mean something so serendipitously beneficial to my position?

You used a term incorrectly as you often do.

Originally posted by no1marauder
What part of the definition given didn't you understand?

I didn't read it. I am so intimately familiar with the concept that I don't need to refer to a layman's glossary.

Originally posted by no1marauder
Professor Wolfram doesn't think so. I gave the link to his definition of proof by contradiction earlier. Here's the one to Reductio ad Absurdum:
http://mathworld.wolfram.com/ReductioadAbsurdum.html

Well, Professor Wolfram disagrees with Frege, Russell, Quine, Putnam, and virtually every logician in recorded history. Further, his "definitions" of proof by contradiction and reductios are, in fact, logically equivalent (since assuming that a proposition is true is equivalent to assuming that its negation, a different proposition, is false).

Originally posted by bbarr
Well, Professor Wolfram disagrees with Frege, Russell, Quine, Putnam, and virtually every logician in recorded history. Further, his "definitions" of proof by contradiction and reductios are, in fact, logically equivalent (since assuming that a proposition is true is equivalent to assuming that its negation, a different proposition, is false).

It's a moot point anyway. Jerkoff wasn't using any proof by contradiction in the first post anyway. That's an after the fact rationalization for writing a logically incoherent post.

No1, you're really out of your league here, and I think you recognize it, seeing as you are now resorting to name calling.

Bbarr, I don't know about you, but I'm going to do the Christian thing and not continue to beat up on somebody much smaller than me for my own amusement, at least for tonight.