Archive | August, 2013

Lions and Tigers and Bears, Oh My!

30 Aug

Our neighbor has a sign by her gate advertising a certain security company.  In our last neighborhood, many homes had also chosen to pay for monthly security.

I don’t know whether it was the lack of funds or that we were just cheap, but my husband and I never talked about whether we should sign up with such a service.  Therefore, my only real ‘knowledge’ of home alarm systems comes from a few TV commercials.  I’ve noticed that they often employ the technique of fear to get you to consider their services.

Don’t you want to protect your family from all the possible ‘bad guys’ out there? Dad might be travelling a lot and away from home.  What’s a fearful mom to do in the middle of the night?

Or if you’re an elderly widow, all alone in her home, who feels vulnerable, what steps SHOULD you take?

Well, what’s wrong with wanting to safeguard your family, or provide for grandma?

Nothing at all! Those are legitimate concerns.  It’s just that they are not the best reasons for going with brand X alarm system.

It’s much EASIER for the company to advertise their product by playing on our fear.  They default to the shortcut or FALLACY, called the Appeal to Fear,  (aka scare tactics.)

It might look like this:

If you don’t arm yourself with our security system, then you might get hurt.

To bolster their claim, they use actors to create a convincing scene:

  • the potential intruder is apprehended by the rapid security company
  • relieved family members offer convincing testimonies.

I have just read Neil Postman’s iconic work, Amusing Ourselves to Death.

  I was startled to learn that before the 1880s, all print advertising promoted their products based on propositional reasons their goods would solve your problem or meet your need. They did not show pictures of cute babies or happy moms or successful blacksmiths content with their purchase.

Today vendors cater to our lazy buying habits by appealing to natural fear.  But we buyers SHOULD ask for evidence that their product will indeed meet our need.  And before we seek reasons, we need to have articulated the exact nature of our need or desire.  And that requires THINKING!

Unfortunately, thinking is becoming more and more an unused muscle!

Gotta stay positive

28 Aug

All Chocolate is satisfying

Ghirardelli is chocolate

Tf, Ghirardelli is not satisfying   

What???  That doesn’t make sense!

You’re right.  Our mind easily balks because Premise 1 and Premise 2 are both affirmative propositions, they are A statements.  And the senseless conclusion is a negative proposition, an E statement (No Ghirardelli is satisfying).

Below is the chart that shows the 4 kinds of propositions and their Quality (Affirmative or Negative)

Affirmative  Propositions                      Negative Propositions

in this column                                         in this column

A – All dogs are cuddly E – No dogs are cuddly
I – Some dogs are cuddly O – Some dogs are not cuddly

So, back to chocolate and the question of validity – We are continuing with our extended lesson of

  • “How to examine a syllogism and see if it’s valid”

There are 7 rules in our Validity Checklist that we must run down to determine if a syllogism is valid , that is, in the correct form.  Last time, we showed that NO conclusion whatsoever can be drawn from 2 negative propositions.  Today, we see from Rule # 6 that

  • if premise 1 & 2 are affirmative, then the conclusion MUST be affirmative as well.

So what happens if someone has asserted a negative claim about health care such as:

  • No costly plans are possible

and when you ask the person WHY??? (Whoever makes an assertion is required to back it up with reasons) he/she says:

Premise 1 – All government plans are possible

Premise 2 – All costly plans are government plans

They’ve JUST articulated two affirmative reasons for their NEGATIVE conclusion of “ No costly plans are possible”

Before you jump in (or down your conversation partner’s throat) and start giving YOUR reasons why you disagree, you have every right to encourage this person to explain what she has either

  • left out on purpose
  • left out because she is not THINKING

Remember, there is absolutely NO point in arguing about an invalid argument.  And a negative conclusion drawn from 2 affirmative premises is one of the 7 ways an argument can be deemed invalid.

An argument (syllogism) must win the ‘Good Logician’s Stamp of Validity ‘ to be considered ready to meet the next criterion – are the premises TRUE.

Two negatives make NOTHING!

26 Aug

         No boys like me

                                        Some of my best friends don’t like me

                                        Tf, my life is awful

What’s wrong with this argument?

-besides being the lament of a ‘too-introspective’ teen girl

-besides consisting of more than 3 terms (violates Rule # 1 of the Valid Argument test)

Here’s what’s wrong – You can’t draw ANY conclusion WHATSOEVER from 2 negative premises.

That’s Rule # 5  for “Evaluating the validity of a syllogism” in a nutshell.

Rules 1 to 4 have focused on

  • the number of terms in a syllogism
  • the occurrences of each term (Major, Minor and Middle) in a proper syllogism
  • the ‘distribution’ of each term, that is –  the reach or how many ‘members in a set’ to which each term applies

With Rule # 5 (there are seven in total), we look now at what is called the QUALITY of  the premises in the syllogism.  Quality refers to whether a proposition is affirmative or negative.

Both common sense AND logic inform us that you can’t get ANYTHING positive out of a negative.  And if you can, then there is more ‘back’ argument that needs to be flushed out (unarticulated pre-suppositions or other propositions).

Imagine someone stepping outside of his office cubicle and shouting seemingly à propos of nothing…..

-the picnic is not going to happen!   

-there is no pizza in the freezer!

– therefore, I’m happy

We’d conclude that this guy was nutty!

So what do we do when we run across an argument in a letter to the editor that is drawing an affirming conclusion from a bunch of negative ‘facts’ – that is, when their premises are either E or O statements?     

(E – No pizza is in the freezer; 0 – Some picnics are not going to happen)

First of all, since we are equipped with logic as a tool, we know to ask for more information.  Their claim, constructed from 2 negative premises, can’t stand on its own.  There HAVE to be affirmative propositions (A  – All food is what makes me happy; I – Some meals are better than no meals).

Don’t be afraid to gently push back against an argument-maker by asking questions.  After all, the burden of proof is on him who makes the claim.

And by the way, this is an easy way out of an argument you might not want to tackle.  If you can point out gently that someone is basing their argument on negative premises, you don’t even HAVE to consider the conclusion – it’s irrational to begin with!

They don’t make peaches like they used to!

23 Aug

Summer peaches – sweet juice running down your chin, a mouthful of flavor!

Hold on, if you’re like me, you’ve often been disappointed.

But before you pass judgment on the quality of peaches or any other fruit and vegetable, let’s look at a potential fallacy.  Yes, welcome to Fallacy Friday.

Today’s false argument is called the Fallacy of Composition and some of us often commit it at the grocery store!

Here’s what it looks like: (let’s imagine a shopper in the produce department at a local New England grocery store)  

The peaches are NEVER good, the tomatoes have no flavor, I’ve tried the Chinese pea pods and they’re tough & stringy …

“ Let’s face it, grocery store produce is not fresh!”

What this unhappy customer has done is assume that because of the lack of freshness in several items of the category ‘New England Grocery Store Produce’, every other member of that category also lacks freshness.  However, operating on that assumption might mean: missing out on the fresh and juicy blueberries that happen to be locally grown and sold to the big grocery store.  

If we assume that because one or more things in a category has a certain quality, then all things in that category are that way, then we have committed the Fallacy of Composition.

The quality or attributes of a whole are not necessarily the same as some members of that group or even ALL the members of the group.

I’ve heard this fallacy used in arguments about gods and religions.

  • Because Thor and Zeus are false gods then every member of the  ‘god’ category is false.
  • Because some people who claim to be Christian have acted in a hypocritical way, then the Christian Church is hypocritical.

Here are some other examples:

  • Each of these ingredients tastes yucky.  Therefore, when put together the finished product must be disgusting!

 

  • If we assemble an all-star team of high-scoring basketball players, then we’ll have a high-scoring team.

 

  • These little paint dots don’t seem to have any sense to them, that guy Van Gogh is just fooling us into thinking he is a real painter.    

So how do we ward off committing this fallacy?  Being aware of the possibility of an incorrect conclusion is probably enough to stop and make us think.  For example, being able to make baskets consistently does NOT necessarily make for a winning team.

What other examples of the Fallacy of Composition have you encountered?

Who gives a darn about distribution?

21 Aug

   Distribution of terms matters….

even if YOU don’t care about distribution, the logic police do!

If we want to be logical and hold others gently to the same standard, we have to follow some rules.  Today we are talking about Rule # 4 – the one smack-dab in the middle of all 7 rules for writing a syllogism in its correct form.

Here is a synopsis of the 3 previous rules

# 1 – Three and only 3 terms are allowed in a syllogism

# 2 – The middle term can’t be in the conclusion

# 3 – If a term is distributed (applies to all in the set) in the conclusion, then it must be distributed in the premises

Today we look at # 4 – The middle term must be distributed at least once.  Since this term connects both the major and the minor terms, then it has to be as ‘ broad ‘ as possible to apply to the major and the minor terms.  We follow the technical drill of labeling the terms in the syllogism. We visually check to see if the middle term is distributed at least once. If not……then we shout FUM!!! (aka – Fallacy of undistributed middle)

                   Some chocolate is dark

                   All yummy foods are dark

                   Tf, some yummy things are chocolate

Types of Propositions Subject Terms Predicate Terms
     
A D U
I U U
E D D
O U D

When we label terms, we start with the conclusion  ‘at the bottom’ and label up.  (the term IN FRONT OF the copula is the subject or minor term…..the term AFTER the copula is the predicate or major term)

Tf,  (an I statement) some yummy things (Su) are chocolate (Pu)

We spot  ‘ yummy things’, then we notice that it is in the ‘ subject position of the proposition’ and write S.  Looking at the chart, we see that for an I statement the term in the subject position is undistributed, hence we add a ‘ u’.  The term ‘ chocolate’ is located in the predicate position of this I proposition; we write P and seeing that in an I statement, a predicate term is ALSO undistributed, we add a ‘ u’ next to the P.

Having identified the Major and Minor terms (also called the Predicate & Subject terms), the ‘ leftover term’  in the syllogism defaults to being the Middle Term (labeled M).  We can now finish labeling Premises 1 & 2.

P1:  (an I statement) Some chocolate (Pu) is dark (M u)

P2: (an A statement) All yummy foods (Sd) are dark(Mu)

So the whole syllogism looks like this:

        Some chocolate (Pu) is dark (Mu)

        All yummy foods  (Sd) are dark(Mu)

        Tf, Some yummy things (Su) are chocolate (Pu)

Is the middle term distributed at least once?  NO!!!

Therefore, we can say to the person making the argument:

“ We can’t even DISCUSS whether your case is sound until your syllogism is in the correct form!  And your middle term of ‘ Dark’ is not distributed even once!  Your conclusion assumes too much, given the data in premises 1 and 2.  You have committed…..FUM – the Fallacy of the Undistributed Middle Term.

  Off to Logic Prison with you!         

How is this useful?  I find that knowing the 7 rules of validity is a quick way to assess a syllogism when I sense that something isn’t quite right. The logic error emerges quickly when I run the argument through this checklist.

Keep an ear open for a conclusion that seems far-reaching and let me know if you’re stumped.  We’ll practice together.

Illicit logic

19 Aug

Now that I have your attention, on with validity!

Last time we chatted about ‘distribution’ of terms.  If a term is distributed, then what we mean is that we’re referring to ALL members of the subject or ALL those the predicate could possibly address.

For example in the proposition No carrots are sweet, we are saying something about ALL carrots and something about ALL ‘sweetness’ as a predicate.  So carrots and sweet are both distributed. 

If we posit……. Some boys are strong, then the terms boys and strong are undistributed because we are talking about only some of the set of boys and only some of the set of strong things.

Why do we care whether a term is distributed or undistributed?  I’m glad you asked!

Remember that we must be precise with our words.  We must not give the impression of ALL if we mean only SOME.  To say that ALL pre-teens get to stay up until midnight is a lot different than SOME do.  Since terms and their quantifiers build propositions which in turn build arguments, accuracy is important.

Often people over-generalize in order to make a point.  We, the recipient of the argument, need to be aware of quantifiers (the all, some, no, some..not) or we’ll be HAD!!!

On to rule 3 of how to test whether a syllogism (argument) is valid (i.e. in the correct FORM):

Rule 3 – if a term in the conclusion is distributed (applies to ALL of a term) , then it also must be distributed in the premises.  This prevents over-reaching conclusions.

To determine whether a term is distributed/undistributed we label our terms by the position they occupy in each of the 3 propositions and in the syllogism itself.  Here is our ‘DUDUs and UUDDs’ chart again from last time.

Subj

Pred

A(all)

D

U

I (some)

U

U

E (no)

D

D

O (some…not)

U

D

 

Some satisfying relationships are happy

Some satisfying relationships are marriages

Tf, all marriages are happy

 

Labeling our terms, starting ‘bottom up’ with the conclusion, we get:

 

Premise 1 –     Some satisfying relationships(Mu) are happy (Pu)

Premise 2 –     Some satisfying relationships (Mu) are marriages (Su)

Conclusion –   Tf, all marriages (Sd)  are happy(Pu)

 

S = subject term is marriages

P = predicate term is happy

M = middle term is satisfying relationships

U = undistributed

D = distributed

 

Rule # 3 states that if a term is distributed in the conclusion, then it has to be distributed in the premises.  We find that marriages IS distributed in the conclusion; however, where the subject term marriages is located in P2, it is NOT distributed because Premise 2 is an “ I” statement (see chart above).

Therefore, we say that the syllogism is INVALID because it violates rule # 3 (of 7 altogether), committing the Fallacy of Illicit Minor (one can violate the minor or the major term.)

Just pronounce the word ‘illicit’ in a class of 8th-graders and you have their instant attention as they wait to hear about SEX!!! 

So I have explained to my rapt class that the term ‘illicit’ means NOT allowed or unlawful.  What we are NOT allowed to conclude is that every single marriage is happy JUST because SOME satisfying relationships are happy and marital ones.   That conclusion goes FARTHER than the information given in premise 1 and premise 2.

Next time we will talk about a fallacy called FUM, where the middle term is undistributed.

In the meantime, as you read and listen to arguments, ask yourself if the conclusion drawn is valid or invalid according to Rule 3.   If you run across an egregious and interesting example, please share! 

Who are you to tell me not to smoke, you do!!

16 Aug

For years as I was raising my boys, I second guessed myself:

I would hesitate in ‘preaching’ that certain behaviors were wrong.  My faulty reasoning went like this:

“I’ll be hypocritical if I tell them…

  • Don’t smoke pot!
  • Don’t have sex before you’re married!
  • Don’t drink and drive!

…..after all, I’ve done some of these.”

I wish I had known about this logical fallacy back then!  Because whether you have smoked, drunk, or whatever, that is irrelevant to a reasoned argument NOT to do something.

This kind of silly thinking is called ‘Tu Quoque’ (too kwo-kway) which means ‘you, too!’

Imagine the following conversation:   

Chain-smoking Uncle Albert –Bobby, what are you doing smoking a cigarette!  Don’t you know you can get lung cancer that way?

12-year-old Bobby:  Who are YOU to tell me not to smoke?!  You can’t go an hour without lighting up!

Uncle Albert:  That’s right!  And I don’t want you to suffer like I have.  I wish someone had told me how addicting smoking was and the impact it would have on my life!  I can’t even climb a flight of stairs now without having to stop and catch my breath.  Do you want to end up like me?

Bobby –But that’s hypocritical to tell me one thing and not do it yourself!

Uncle Albert –No, it’s not hypocritical.  If I CLAIMED not to smoke and lectured you about the dangers of smoking, and then you caught me smoking, then I would be two-faced. But I’m giving you good reasons why smoking is bad for you.

Bobby – Hm, you’ve got a point.  Alright, I won’t  smoke any more.  Just don’t tell Mom, okay?

Here’s what thoughtful reasoning does.  It makes an assertion and then backs it up with reasons.  The personal habits of the one making the claim have no bearing on the case.  In fact, having experienced some nasty consequences for engaging in dangerous behavior might make the case even more compelling, but on an emotional level.  We’ll leave that to the rhetoricians and stick to reasonable, thought-out positions.

Here is a sample argument supported by reasons:

Premise 1   Practices that are harmful to your health are actions that should be avoided

Premise 2   Smoking cigarettes is a practice that is harmful to your health

Conclusion  Tf, smoking cigarettes is an action that should be avoided.

So – go ahead and share your hard-earned wisdom!  And if someone objects, tell them that it is a fallacy to say that you can’t give advice regarding something that still has you in its grip!