I'm new, and I come bearing a question.

[Richard Baron]

"Students ........ have a natural expectation that the premises should do some work and should be relevant to the conclusion - things that are true of the arguments that we find useful in real life."

But are these things TRUE of the arguments we find useful in real life?

I stand corrected. True of the arguments that are not in any way underhand and that we find useful in real life.

Actually I somewhat disagree about pushing 'the consequences of practical need very far'. I agree that modal logic is not obviously useful in everyday life, but I think the need for basic logical reasoning has never been greater. (Mind you the public need for scientific 'literacy' and for a public understanding of statistics is also great.)

I agree that the need is great, both for logical reasoning and for mathematical and scientific literacy. When I spoke of "very far", I had in mind the range of (often tacit) knowledge that would be required in order to get on in the world, rather than the strength of the need. But the sophistication of the modern world, and the growing power of some organisations, including governments, to do things, may of course mean that the required range of knowledge has grown. You do not need the statistical knowledge to appraise claims that are made on behalf of social policies, or of new medicines, until such things exist.

[Arising_uk]

I wasn't trying to say that it was all useless information, which I believe Ray and Arising took it as.

What I was wondering was, what would be the need for such a question as the one below, in any other place but in a symbolic logic class.

DvE
(DvF)[horsehoe]G
~G[horseshoe]~E
______________
G
?

I couldn't figure out how to type the horseshoe or if-then variable, so as you can see, I just typed it out.

Sorry ch33z3,
I was attempting to be satirical or ironic.

You can just use -> for the 'horseshoe' if you mean by it material-implication.
So did you mean this?
(D v E)
((D v F)->G)
(¬G -> ¬E)
therefore G

or this,
(D v E)
((D v F)->G)
(¬G -> ¬E)
G
therefore ?

As to the point of SL for students within Philosophy I'd say it plays the role that Mathematics does to mathematicians and the role that it plays for Engineers and Technicians. So the practice of trying to grasp SL is just good training for 'thinking' or 'thought', a la Maths. That it teaches one to notice how 'If...Then', And, Or, 'Not', All, Every, 'Identity', Neither...Nor, Either...Or and all the other logical constants, work within all languages can only bode well for those wishing to practice 'critical thought' and is like the engineer who uses Maths as a 'tool' I'd say. Hope this helps with your 'distress' as I remember that well but now find it one of the most interesting pastimes for a budding philosopher, that and phenomenology.

[i blame blame]

Hello everybody. I'm taking a philosophy course in college right now, Symbolic Logic, and I just don't understand the need for it. I'm all for learning for learning's sake, but this is starting to take the place of trigonometry as the most useless thing I've been forced to learn. Ok, not all of it was bad, but right now we are doing the rules of derivations. I was wondering if anyone could shed light on the use of any of this, because to me it seems completely irrelevant to anything; a system on a system that has no use. Thank you for any help!

http://abstrusegoose.com/206

[ksdjhjkfg56]

It is true that the arguments that get used as examples in courses tend to be trivial ones. You can see straightaway whether the argument is valid or not. But:

(i) there are more complicated arguments around, and once you learn how to analyse the easy ones, you will be able to analyse the more complex ones. There is an analogy with engineers who handle all the complicated equations that they need in order to build bridges that stay up, or whatever. They are applying techniques that they first learnt with really easy equations, like 3x + 7 = 43;

(ii) philosophical arguments are often expressed in continuous prose, and generally first occur to their authors in that form. One of the best ways to test them for validity, and to reveal unspoken assumptions, is to translate them into the language of symbolic logic. Again, the techniques you need in order to do that are the ones that you learn by doing simple examples;

(iii) if you grasp how logical systems work, you can then go on to grasp important results about logical systems, for example soundness results (if you can prove it, then it must be true), completeness results (if it must be true, then you can prove it) and, most interestingly, incompleteness results (in some systems, you cannot prove things even though they must be true). These are rough and ready statements of soundness, completeness and incompleteness. The true significance of these results can only be grasped if you have a bit of symbolic logic.

This is completely consistent with not only Christian traditions, but also ... Christianity and Contraception: History and Development of Christian Perspe
[SPAM LINK DELETED]

[Richard Baron]

This is completely consistent with not only Christian traditions, but also ... Christianity and Contraception: History and Development of Christian Perspe

Consistent, in the sense that it is possible to produce arguments for various religious positions that observe the constraints of logic. See for example Elizabeth Anscombe's Contraception and Chastity, a Catholic Truth Society pamphlet. That pamphlet famously provoked a response from Bernard Williams and Michael Tanner, available here (you may have to click on a button on the first screen to get to it):

http://www.uq.edu.au/~pdwgrey/web/res/contracept.html

I choose this example because it nicely illustrates the need to go beyond checking that the rules of logic have been observed. One must also start from correct factual assertions (see the Williams-Tanner remarks on homosexual relationships). Less obviously, but just as importantly, one must tackle the problem in the right way. Whether one has done that can only be established by reference to the subject matter. One must consider what the argument is about, as well as its merely formal characteristics (see the Williams-Tanner remarks on the characterisation of actions).

Incidentally, ksdjhjkfg56, someone has polluted your post with an irrelevant link to an advert for DVDs. (I have not clicked on the link, and would advise others not to click on it either, lest it lead to some nasty virus, but the code indicates that this is what it is.) I see that your other posts are similarly polluted, and fear that you may be a spambot, and therefore at risk of being eliminated by moderators. That would be a shame, since your comments can provoke worthwhile reflection.

[RickLewis]

Incidentally, ksdjhjkfg56, someone has polluted your post with an irrelevant link to an advert for DVDs. (I have not clicked on the link, and would advise others not to click on it either, lest it lead to some nasty virus, but the code indicates that this is what it is.) I see that your other posts are similarly polluted, and fear that you may be a spambot, and therefore at risk of being eliminated by moderators. That would be a shame, since your comments can provoke worthwhile reflection.

Alas, the thought that ksdjhjkfg56 might be a spambot had indeed occurred to me (and also crossed the mind of the Nameless One, who reported the posts as spam). I have therefore deactivated his/her/its account, though not without some hesitation. If this is a spambot (and I presume it is) then it is the classiest one I've ever seen - its postings really do look as if they correspond to the topic of each thread.

ksdjhjkfg56, if you AREN'T a spambot, please feel free to create a new account and then message me if you are having technical problems.

Rather than simply delete ksdjhjkfg56's postings, I'll leave them up and simply delete the links within them in case they lead to any nasty viruses.

[Wootah]

It's a spam bot.
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Just like Ray
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