Friday, February 20, 2009

A Little Help with Some Deductive Reasoning, Please

I need a little help with a deductive argument. Please tell me if the last proposition in the below argument is true or false:
Stipulation: All Hs prefer P or ~P [Hs prefer P or ~P but not both]
Premise 1: if H prefers P --> H prefers L
Premise 2: if H prefers ~P --> H prefers ~L
Premise 3: (H prefers L) is True
[Therefore]: The inference, or conclusion, [(H prefers P) is True] is valid
N.B. In the above argument the symbol "~" means "not" or "negation."

&&&
"Why do I ask?," you ask.

That's a fair question. So I'll answer it.

Answer: The above argument may become part of a broader argument; it may become embedded in a broader argument.

I may post the broader argument later. Or maybe I won't. (Now there's deductive logic for you!)

If I do post the broader argument, I won't hold you responsible for the broader argument. And you won't in fact be responsible for it -- and that's a fact.

So, someone in the silent majority, you help out. If you do, your reward will be the knowledge that you have contributed to knowledge -- and to the assessment of you-are-for-us-or-against-us reasoning.

the dynamic evidence page

coming soon: the law of evidence on Spindle Law

2 comments:

Anonymous said...

(Delurking after a year or two as a faithful reader)
That argument looks like an example of affirming the consequent, which is almost always classified as a type of fallacy...

Unknown said...

Do you think the amendment suggested by my colleague (see my next post) avoids the fallacy? My sense is that the answer is "yes." Do you agree?