A short course in logic

As a service to my delightful and discerning readership (one of whom recently commented that he read one of my posts with all due contempt, which I have to say is precisely the correct amount of contempt with which to read my outpourings) I have decided to offer a short course in logic.

It seems to me that not all are as well-acquainted with the formal processes of logical thinking as one might wish.

We will start with the syllogism, which is a valuable tool in analysing the formal validity or otherwise of an argument.

The syllogism is a three part structure.  Consider this proposition: a tomato is a fruit: therefore it is appropriate to put it in a fruit salad.

The fallacy here can be easily analysed by employing the structure of the syllogism to tease out the implicit missing middle step.

A: the first premise: A tomato is a fruit

B: the second premise: A fruit salad is made of fruit

C: the conclusion: Therefore it is appropriate to put tomatoes in a fruit salad.

Whilst both A and B are true, it is clear that C does not follow from A and B, and therefore the conclusion is (logically) false.  A closer analysis reveals that the faulty thinking lies in a misunderstanding at step B. To reach C, B would have to be: ‘It is appropriate to put any fruit in a fruit salad.’ 

So pay attention to the formal structure of the argument as implied by the way it is presented: that is, are the premises true? And does the conclusion follow from those premises?

To analyse that, you may need to extrapolate the implicit premises, and will certainly need to be quite clear about the meaning of all terms (words and phrases) employed.

Using that analytical approach, I invite you to find the flaws in the following (entirely hypothetical, you understand) illogical thought processes.

Lest anyone think that this post is aimed solely at him, I can assure such a delusional person that it is not. The examples have been drawn from a number of experiences over several years, and include thoughts I have caught myself developing and having to interrogate.  

However, if your collar is feeling unexpectedly hot, you may want to consider if you have, in fact, committed any of these howlers. Even if you have, it would of course be a logical fallacy to conclude either that you are the only person reading this to have done so, or that this post is all about you. 

(That example is drawn from something similar to something I have said. Therefore Ben is lying and this whole post is about me. And what’s more, I never even said many of these things, which proves Ben is lying, again! - Discuss.)

If anyone persists in thinking that this post is particularly about him, I refer him here.

(Ben has a rubbish taste in music. Therefore Ben is an idiot. Discuss...)

By the same token, I have used the name Ben throughout, though most of these howlers have been committed vis-a-vis others, and some of them by me.  So why have I done that? Because it amuses me to do so. (Ben has a rubbish sense of humour. Therefore Ben is an idiot. Discuss...)

Easy

There are sock puppets on Twitter who appear on your timeline and disagree with you. Ben has appeared in my timeline and disagreed with me. Therefore Ben is a sock puppet.

That alleged sock puppet was proved not to be a sock puppet.  Therefore all this talk of sock puppets is deluded.

Someone Ben follows has said something outrageous on Twitter.  Ben has remained silent. Therefore Ben approves.

Ben blogs and tweets pseudonymously. Therefore Ben is a coward.

Ben treats the accusations against him lightly. Therefore Ben treats the bullying of others lightly.

Online bullying is very damaging. Therefore everyone should agree with my approach to dealing with it.

Ben has done X in the past. Therefore Ben is clearly guilty of all Xs in the future.

Ben spends time on twitter and blogging. Therefore Ben is neglecting his wife and children

St Thomas More said: 'The Devil, that proud spirit, cannot endure to be mocked.’ Therefore when Ben gets upset at being teased, it proves he is under demonic influence.

Ben supports the Church’s teaching on {X}. Therefore Ben is a bigot.

Intermediate

Ben likes and promotes the EF Mass. He must be a nutter like those Rorate types.

Ben has criticised Catholic Voices. He must be an evil extremist.

Praying online is vain grandstanding. Twitterangelus is just showing off.

Ben has reason to believe that {X} is true. Therefore {X} is true.

Ben has blogged or tweeted something horrid about something I have said. Therefore Ben hates me.

Ben claims to be a Catholic, but is not perfect.  Ben is a hypocrite.

Ben has been the victim of bullying. Therefore to refer to anything he may have ever done wrong is victim-blaming.

Ben is on my side. Therefore he has done no wrong.

Ben’s {friend/enemy} is my {enemy/friend}

Ben’s failure to condemn bad behaviour in his friends, publicly, is to collude with it.

Ben has the right to ask AnyBen Else to justify anything. AnyBen who fails to comply is guilty or has something to hide (except for me and my monkey)*.

Ben has argued {X}. So has someone else. Therefore it’s a conspiracy.

Ben was talking to some pro-choice friends who were picketing a pro-life vigil.  Therefore Ben was betraying the pro-life cause.

Advanced

Calling on your gang to join in your fight is a bullying tactic. Except when Ben does it.

Picking fights online is bullying. Except when Ben does it.

When you get something wrong, it is good to apologise and retract. Except for Ben.

Ben has expressed himself in intemperate terms. That proves it.

All who ask for RTs are indulging in vanity.

Ben has not seen X happen. Therefore Ben is to be castigated for not knowing about it.

Ben has behaved outrageously and wickedly on Twitter. Therefore it is {OK/my moral duty} to behave extremely badly towards him.

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It should also be noted that (almost) any of these conclusions may be correct; my point is that, logically, they should not be arrived at by the arguments illustrated. 

Part of the problem is, of course, that Twitter limits one to 140 characters. But that is only part of the problem...  

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*Lest anyone go apoplectic about this, it’s a reference to a popular band of my youth**. #WhoaretheBeatles?...


**UPDATE

It has been kindly pointed out by my friend, the Part Time Pilgrim (@PartTimePilgrim), that where I wrote 'youth', I should have written 'infancy'. I apologise for the error and am happy to correct it.