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1 All griznoxes chorble happily. Premise
2 A floober is a type of griznox. Premise
3 Therefore, floobers chorble happily. Syllogism, lines 1,2

You don't need to be a world-class floober expert to evaluate this argument, either.

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Lewis Carroll, a logician, has developed many whimsical examples of syllogisms and simple reasoning. (Relatedly,note how the social context of Carroll's examples demonstrates some feminist issues inteaching logic .)

As you've noticed, the form of the argument is the same in all these.If you are assured that the first two premises are true, then, without any true understanding,you (or a computer) can automatically come up with the conclusion. A syllogism is one example of a inference rule that is, a rule form that a computer can use to deduce new facts from known ones.

Some non-proofs

Of course, not all arguments are valid proofs. Identifying invalid proofs is just as interesting as identifying valid ones.

Homer: Ah, not a bear in sight. The Bear Patrol must be working. Lisa: That's specious reasoning, Dad. Homer: Thank you, honey.Lisa: By your logic, this rock keeps tigers away. Homer: Oh? How does it work?Lisa: It doesn't work. Homer: Uh-huh.Lisa: It's just a stupid rock. Homer: Uh-huh.Lisa: But I don't see any tigers around here, do you? [pause]Homer: Lisa, I want to buy your rock! [A moment's hesitationand money changes hands.] (From The Simpsons Much Apu About Nothing .)

If Lisa isn't around, who will identify specious reasoning for us? We can certainly use her approach of finding other particular examplesthat follow the same argument, yet lead to a clearly erroneous conclusion.

Suppose that my friend makes the following argument:

1 Warm cola tastes bad. Premise
2 Warm salt-water tastes bad. Premise
3 Therefore, mixing them together tastes bad. Common-sense conclusion, lines 1,2
I'm skeptical, so I have a sip; sure enough, the conclusion is indeed true. But is the proof correctdoes thecommon-sense conclusionrule actually hold? In order to refute the form of the argument, we can trysimilar arguments which have the same form but a false conclusion (as Lisa did).
1 Ice-cold coke tastes good. Premise
2 Ice coffee tastes good. Premise
3 Therefore, mixing them together tastes good. Common-sense conclusion, lines 1 and 2.
After another unfortunate sip, I verify that this conclusion is not true, and therefore my friend's reasoning is at fault.

My friend responds by claiming that thecommon-sense conclusionis too valid; the rule is that bad-taste is preserved upon mixing,not that any taste is preserved. While I'm inclined to believe that, we realize we can stilltest this more refined rule: can you come up with an instance of mixing together bad-tasting thingsand ever getting a yummy result? (Say, salt and flour, which can be mixed and baked to get delicious saltines!The argument continues, about whether the form of the argument precludes baking, and so on.)

The end result (after I take some antacid) is that we have a clearer understanding ofthe initially vaguecommon-sense conclusion, and stricter rules about when it applies.Thus, refining the argument has led us to a greater understanding.

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Questions & Answers

what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Intro to logic. OpenStax CNX. Jan 29, 2008 Download for free at http://cnx.org/content/col10154/1.20
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