Of course, another article on the Nigerian billionaire Esenam Ayele will get some more BBelievers ...
Date: Wed, Jan 28, 2009 at 7:13 PM
Subject: RE: Logical? (mailbag)
To: Brian Briggs
I was going to post a follow-up in the comments section, which I read after sending you an e-mail, decided not to, and then you replied via e-mail, so now I feel compelled to follow-up after all.
I missed this the first time I went through the question, but it's there in plain view:
a) Water is a molecule composed of two hydrogen atoms and one oxygen atom.
b) Every observation or examination by microscope has confirmed this.
Therefore we can predict that every future examination of water will reveal the same chemical composition.
Nowhere in the conclusion is a "microscope" mentioned. Can you confirm, with your two eyes (I assume you haven't had any ocular-involved accidents recently), that water is composed of two hydrogen and one oxygen atoms? Can you taste the hydrogen or feel the oxygen? There's an assumption by the reader that the future examinations would also be made with microscopes, but that's not what the question asks.
Anyway, I do agree that the question is poorly written. After all, you can't actually identify particular types of atoms with microscopes anyway.
Date: Fri, Jan 30, 2009 at 2:35 PM
Subject: Logic Test
Actually, the fifteenth question in the linked logic test is truly invalid, but not for the reason given by the "answer".
1. The author confused a descriptive definition of water with the prescriptive definition that water necessarily is composed of two hydrogens and one oxygen. Saying "all water observed has two atoms of hydrogen and one of oxygen" as the first premise would give the results the author intended.
2. The reason the argument is really invalid is in the wording of the conclusion: "Therefore we can predict that every future examination of water will reveal the same chemical composition". While water WILL always have the same chemical composition, in line with premise #1, that does not mean that a future examination will CORRECTLY demonstrate that composition. The future examination may incorrectly identify water as H2O2.
premise: Your site is awesome.
premise: I deserve free awesomeness.
conclusion: You must keep up the good work.
Date: Fri, Jan 30, 2009 at 6:19 PM
Subject: Logic Test
You're right. They messed that one up. It is odd that the test-makers
got #15 wrong, but they were able to get #7 and #10 right. #7 and #10
also make premises that some philosophers disagree with, but in a logic
puzzle, you must assume whatever it is you are supposed to assume.
a) Anybody who would get #15 wrong does not understand logic
b) It is impossible and a waste of time, to have a discussion with
someone who does not understand logic
c) an argument is a form of discussion
Arguing this question with people who got #15 wrong is a waste of time.
These people need to read up on basic logic. They need to know what a
premise is, which they don't, and you are unlikely to convince them
to actually look it up, even if you were to supply links.
Date: Fri, Jan 30, 2009 at 7:25 PM
Subject: my logic pic
To: Brian Briggs <email@example.com>
So, here's my take on your logic problem with graphics.