Archive | September, 2013

Logical Gal and The Law of Identity

30 Sep

If in a game of trivia,  you were put on the spot to offer ONE quote associated with Bill Clinton, most of you would shout, “It depends on what IS is!”

Words do matter.  And terms are verbal or written words that describe the essence of a concept.

The Law of Identity is useful because it removes wiggle room when people start playing loose with terms.

Considered one of  3 foundational Laws of classical thought, the Law of Identity goes like this.

A = A

A ≠ non-A

An apple is an apple….an apple is not a non-apple.

So…..?(the best 2-letter word in the dictionary!) what’s so deep about that?

The Law of Identity can help us think about very current and controversial topics.

Take marriage

At its most basic level,

Marriage    =/is     a contractual relationship between one man and one woman that is consummated by sexual intercourse

The Law of Identity stipulates that what is on the left of the =/is  (the Subject)  is the same as what is on the right of the =/is   (the Predicate)

So if we take away or add or change any part of the description (the predicate), then we don’t have marriage.  We have described a DIFFERENT concept and we need to use a different term.

Here’s another example:

A bachelor is an unmarried man

Change the predicate and you don’t have a bachelor.  You have something else.

So before you engage in endless debates, clarify the terms.  The Law of Identity prevents the Fallacy of Equivocation, which is playing loose and fancy with terms.   It’s a way to start untangling difficult issues.

Spotting the Fallacy of Composition

27 Sep

Just because one member of an organization acts a certain way, it does not follow that the whole organization shares that same attribute.

This is called the Fallacy of Composition.

A recent letter to the editor in the Asheville, NC paper gave evidence that the writer does not understand this faulty thinking.  When people resort to using fallacies (inaccurate assumptions), they undermine the persuasiveness of their point.

Understanding fallacies can be a useful tool for policing up OUR own positions, whether verbal or written.

The way the letter preceded was thus:

The author wanted to attack an organization, so he brought up a fact (which I am going to take as true, for the sake of this explanation) that a past director of that group had been arrested and charged with aiding & abetting prostitution.   We actually don’t know the outcome of the charge.  But if it were found out to be true, no one would deny that the guy had done something bad.     

BUT, it does not follow that others associated with that organization engages in illegal exploitation of women.  The attributes of individual members of a set do not translate into a group attribute or even mean that other members share the same attribute.

Here are some other common examples:

  • a few Catholics supporting abortion rights does not mean the Catholic Church is in favor of this policy
  • mom & dad liking okra doesn’t mean the whole Jones family likes okra

  • Westboro Baptist Church engaging in hateful practices at the funerals of fallen servicemen should not be taken to be the way ALL Christian churches are

The next time someone hits you with an argument based on the Fallacy of Composition, respond with that useful 2-letter word:




What if….it rains on my wedding day?

25 Sep

Saturday, it POURED in the Asheville area of Western NC. 

Normally we hike, my husband and I.  But as we went to bed Friday night, Mike gloomily looked up from checking his Weather Bug app and announced, “ 90 % chance of rain!”

So we did a field trip into the Big City of Asheville and walked around in the rain, stopping in at Topps for shoes and sampling good food at Black Bird Café.

On our way home in driving rain, I casually mentioned to Mike, “Pity the poor couple who planned a lovely Fall Wedding OUTDOORS!”    

Come to find out, a colleague at work WAS part of the bridal party in what was to be an outdoor wedding.

“ Hors de question!”  out of the question, as it turned out.

So here’s the syllogism:

If it rains, then we’ll have to move the wedding indoors

It’s raining,

Therefore, we must move the wedding indoors

This is called a conditional syllogism, part of the class of hypotheticals.

We test the validity of hypotheticals differently.

The major premise is the complex one, the “if/then statement” .

The normal categorical proposition that follows the IF – in this case, It rains

is called the Antecedent.  And the proposition that follows the THEN – in this case, we’ll have to moved the wedding indoors is called the consequent

There are 4 possibilities for arranging the minor premise and the conclusion.  Two are valid and 2 are invalid because they assume too much.

Here are the valid ones , side by side, with their names

If it rains, then we’ll move the wedding indoors          If it rains, then we’ll move the wedding indoors

It’s raining                                                                                    We’re not moving the wedding indoors

Tf, we’re moving the wedding indoors                             Tf, it’s not raining

Affirming the Antecedent                                                      Denying the consequent

(Modus Ponens in Latin)                                                         (Modus Tollens in Latin)

To remember which segment to affirm or deny to be valid, I created a silly statement.

“ AA (alcoholics anonymous) meets in DC (Washington) is valid”     

So we can either affirm the antecedent or deny the consequent and have a valid conditional argument.

If however, we propose the other 2 possibilities, we are stuck with INVALID arguments.

If we DENY the antecedent we get the following:

If it rains, then we will move the wedding indoors

It’s not raining                       

Tf, we’re not moving the wedding indoors

This is not valid, because there are OTHER possible reasons one might be forced to move the wedding indoors.  There could be a snow storm…..the beach could have been eroded….the patio of the Historic Inn could have been double booked.

The other invalid version is this:

If it rains, then we will move the wedding indoors

We’re moving the wedding indoors

Tf, it must be raining

Again, there are a range of other reasons that might cause the wedding to moved indoors.  We don’t have enough information to conclude that rain is the decisive factor.

The ONLY fact we had was this:  That if rain came, the wedding WOULD FOR SURE be moved indoors.  No other contingency plans were described in the syllogism.

Listen next time you hear an “if-then” statement and see if you can determine if it’s valid.

By the way, the bride owes a hearty thanks to her bridal party who pulled off the herculean task of last minute decorating inside!!

It’s biblical!

23 Sep

“Unlike the welfare state, prostitution is biblical!” –


This final jab by a local newspaper reader’s letter to the editor was meant to snarkily shut down a Republican columnist.  The government minimalist had explained that many conservatives advocate the Bible’s pattern of family and faith communities support for the poor rather than depending on the state to provide benefits.  

The premise ‘prostitution is biblical’ is actually an enthymeme. Remember them?  Those are informal arguments that are missing one or two premises. Usually the parties to a conversation know the missing claims, so the proponent feels that to articulate the obvious would be a waste of breath or ink.

 One sibling to another:  What’s for dinner? 

The response:  It’s Tuesday!   

 What goes unsaid is the following:  ‘Mom always serves meatloaf on Tuesdays, so if today is Tuesday, then we’re having meatloaf!”

In the case of the premise:  “It’s biblical” we can’t be sure of the rest of the argument.  It would be helpful to actually engage with the one who advanced the statement.  But if the proponent is not around to enlighten you, you have to consider what he or she might have meant.

Here’s how one context could be construed:

 All practices in the Bible are commendable behaviors

“Prostitution is a biblical practice” (the comment by the letter writer)

Tf, prostitution is a commendable behavior

The above syllogism IS valid.  But is it true?   

Not at all!  Just because something is in the Bible, does NOT mean that God endorses it.  David committed adultery and arranged a murder.  Abraham passed his wife off as his sister – twice!! – to save his skin.  Jewish religious leaders manipulated the Roman officials to eliminate by execution a problem teacher – Jesus!  Peter turned coward and denied Jesus!  A Jewish man throws his concubine to a frenzied crowd who rapes & kills her; the man then callously cuts her into 12 pieces and sends a piece to each of the 12 tribes of Jacob.  The Bible is, in large part, the history of humankind’s sinful mistakes and the account of how a loving God planned and executed our rescue!  So just because accounts of dishonesty, rape, murder and pillage are biblical, i.e. IN THE BIBLE, that does NOT mean God condones them.  Au contraire!  (They actually offer credibility to this holy book – if YOU were going to make up a religion and its teachings, would you show the seamy side of your followers?)

Here’s the takeaway: when you are ‘bestowed’ an enthymeme, simply ask politely for clarification.  Just what does the argument-advancer have in mind when he or she pronounces what turns out to be an argument only partially articulated?  Make them turn that enthymeme into an explicit argument.


But Mom, EVERYone…….

20 Sep

“ But Mom, I’m the only kid in 4th grade who doesn’t have a cell phone!” 

How’s that for an appeal to faulty logic!

If Mom falls for it, her daughter will have successfully employed the  Mob Appeal fallacy (Ad Populum) to twist Mom’s arm.

Mom should take the time to encourage her daughter to THINK deeper by responding –

“ That’s not a good reason.  Convince me of why you, at age 9, should have a cell phone.  What practical reason can you advance?”

Bandwagon or Mob appeal often surfaces during elections.  Proponents of a candidate tend to make frequent appeals to the collective opinion of the majority in order to persuade you of the ‘ rightness’ of a view.

  • You should vote for John in the Student Council elections.  Everyone is going to.

A thoughtful person would retort – “Well maybe every one is making a poor choice.  What are John’s plans for the school?  How has he followed through on previous campaign promises? “

A few years ago, a British newspaper ran a headline after President Bush was re-elected, something to the effect of “ How could 100 million Americans be so wrong!”   The implication seemed to be a NOT-so-veiled accusation that those who voted for George W. Bush just went along with the crowd and did not have a valid reason for re-electing him. If that’s true, then we have an example of Mob Appeal.    

Remember  – just because a majority of people act or think a certain way says nothing about rightness or wrongness.  All one can conclude is that a lot of people acted/thought thus.

Reasonable and thoughtful people at least make AN EFFORT to find a rational justification for believing what they do.  If you can’t articulate WHY you think something, you haven’t thought deep enough.

But take heart, your going along with the crowd is what McDonald’ s banks on!.  Thanks in part to enough non-rational consumers, they do a good business!.

How using logic can help your kids

18 Sep

What do you do at dinner time?

I have taught  school for 21 years.  What saddens me the most among all socio-economic levels of students is the growing tendency of family members to each supper separately.   Parents do not realize the impact of regular meals enjoyed ‘en famille’ .

I am the mom of two grown sons.  My husband and I made lots of mistakes as parents (we never attended the ‘Parent Academy’ nor did I read parenting books – they made me feel too guilty!) But one practice I now realize that we did well, was our commitment to sharing one communal meal daily.

Sure we had our battles over vegetables and table manners, but those were secondary to our goal of conversation.  Our boys are blessed to have a dad who is interested in everything.   Our discussions lasted longer than the food on our plates.  We would talk about what was going on in their classrooms, in the world, at church, with their friends.   Music, movies and books were also frequent topics.

Our family is VERY opinionated, so the boys grew up listening to their dad’s views and practicing the skill of articulating and defending their own views.

Input is important. Children need to have modeled for them HOW to discuss intelligently.  But equally useful  is the day-after-day practice in getting words out of one’s head and into the mix.

When Oldest Son left for college and the family dynamic changed, second son was 12 years old.  We quickly realized that he had not been able to get a word in edgewise due to Dad & Older Son’s conversations. .  It took him a LONG time to grow fluent in explaining and defending his views.

Here is my point – meal time is a training ground.  It doesn’t have to be the dinner hour, maybe the one meal a family can guarantee that all are present is breakfast.  What’s important is that there is leisurely time to eat and discuss.  

I teach French so I am aware of some cultural differences.  Europeans in general spend more time over meals.  They talk.  A lot!  In fact, when one of our sons attended a French language course one summer, he related how political the other teens were.  When they were hanging out at the beach together, a revisited topic was often European politics.  How typical is that in the US?   Do you think these European 16 yr olds just naturally gravitate toward politics and world events?  No, they were trained in the home at at the café!    

So, how does logic play into this?  Easy.  When you have face -to -face time with your children, (i.e. meal time)  ask them what they thought about:

  • A  recent movie ending
  • How a teacher handled a difficulty in class that day
  • A local event or world problem
  • What they heard in church
  • A disputed call in a game by a referee

Possible topics are endless.  Here is how to get them to begin to apply logic.

  1. you can ask them what they mean by a term – that will get them to think ” What do you mean by ‘ unfair’ ?”
  2. you can ask them their reasons for what they think – ” How did you arrive at your conclusion?”

You can frame something by making it conditional – “ What do you think would happen if……”

You have many more potential hours with your kids, to influence them FOR the good.  If you don’t train them to think, then they are likely to just react or go along with a peer suggestion when they get on their own.  Now  THAT’s a scary thought!  

A useful two-letter word

16 Sep

The accusatory screed drips with venom: “Corporate CEOs are all rich!”

Verbal attacks are nothing new.   One can substitute any forcefully-announced statement to clobber YOU who have an opposing view. To wit:

  • ·         Johnny gets to stay up until 10 pm on a school night!
  • ·         The rich aren’t paying their fair share!
  • ·         Fast-food workers can’t earn a living wage!
  • ·         Public school teachers don’t have to contribute as much for their health insurance coverage!
  • ·         Susie’s mom doesn’t have to put up with a lazy child like you!

What is the most effective response to an emotion-laden claim?  The little word:  So?

Don’t feel like you have to fall back to counter arguments that begin like this….

  • ·         My uncle is a CEO of a small book-binding company and he and his family certainly are not rich
  • ·         I know plenty of 3rd graders who have to be in bed by 9 pm during the school week…
  • ·         I happen to know a few ‘rich’ people who pay LOTS in taxes…
  • ·         Maybe it’s not a bad idea for a person to hold down TWO minimum-wage jobs

….instead take a deep breath and say the two-letter word, “So?”  Then pause to listen for their rationale.  What you have just done is give them the space and the invitation to explain to you their unarticulated pre-suppositions.

Last week we began to examine ‘enthymemes’.  That’s a fancy term for an informal argument that is missing one or more premises or even the conclusion.  The unarticulated parts are in the argument-advancer’s mind.  He just didn’t mention them.

·         When someone says, “Shucks, it’s raining!”, that statement is part of a larger argument

If it rains, the wedding ceremony will have to be moved indoors.

It’s raining

Tf, the wedding ceremony will have to be moved indoors.

So, too, with the earlier claims, they are part of an incomplete argument.

When someone condemns CEOs for being rich, this is probably what their argument looks like

Rich people are bad

Corporate CEOS are rich people

Tf, Corporate CEO are bad

Once you help your conversational partner spell out their 1st premise, then you can gently ask them whatever next comes to mind.  I would probably probe by inquiring,   

  • “Why do you consider rich people bad?”
  • Or, “What is so bad about rich people?”

At the very least, you have gotten the other person to THINK. Maybe he or she is just passing on something picked up in the air, on TV or from a friend.  It might not really be what he/she thinks.  You are doing people a service when you take the time to ask them with sincerity what they mean and why they view life the way they do.  And you are showing them THEIR responsibility to have reasons for what they believe.   

That’s so old school…..vs….Back in my day….

13 Sep

Sue:  I can’t wait until I can ditch this old iPhone 5 and get the latest version?

Mary: But you just replaced your iPhone 4  in June?  What’s your hurry? 

Sue:  The upgraded IOS makes this new phone quicker and besides, I just know it’s better!

Mary:  How do you  know it’s better? 

Sue:  It’s the newest!

Welcome to another Fallacy Friday!  Today we are looking Chronological Snobbery.  This fallacious defense rests on the premise that just because something is more modern, then it automatically follows that it is better.  Whereas that MAY be the case, it is not axiomatic that newer is better.  I remember when my husband purchased a computer loaded with Windows 8 , the latest operating system at the time.  It turned out to be NOT as good as the previous version.

Chronological Snobbery can also apply in the opposite direction – one can assume that ‘older is better’.  Many connoisseurs of wine will assert that red wines improve with age.  But that is not always the case.  Corking and storage conditions as well as the quality of a particular year’s harvest will affect the condition of the wine.   

So how do you avoid this faulty reasoning?  Just make sure that you have reason-based evidence to back up your claim that something new OR old is actually better.

One particular arena where Chronological Snobbery is so arrogantly employed is in the evaluation of the validity of the Old Testament.  Many so-called Bible scholars look down on the Hebrews of Abraham’ s day or the time of the Prophets and assume that these ‘primitive people’  had a misguided outlook on the world.  The ‘scholars’ then discount the writings of the Old Testament as not being accurate simply because of the time they were written.   One is ALWAYS perfectly justified to dig a bit deeper when confronting a claim that smells like a case of Chronological Snobbery.  Just ask WHY something newer or older is better.  ” Just cuz”  is not enough of an answer!

Help me, Help me! I’ve been attacked by an “ENTHYMEME!”

11 Sep

A friend recounted a recent example of an attack of ‘unreasonableness’ aka – Where’s the Logic??? in everyday life.  Her conversation at the Eye Doctor’s went like this:

Customer:  What’s this charge?

Optometrist’s Clerk: That’s the “Contact Lens Consulting Fee”

Customer:  But there was no consultation, like last time. Why does it show up on my statement this time, since all I’m doing is ordering more contacts?

Clerk:  Well, you paid it last time!

My friend quickly recognized that she was going to have re-visit THIS bill if she didn’t want to be overcharged.  What actually happened was an improper use of enthymemes!

An enthymeme (pronounced EN-TA-MEME) is an informal argument that has an unstated premise.

We often rely on enthymemes to communicate quickly.  When my husband and his brother were kids, their mom had a routinized supper schedule.  That is to say that she served the same main course on the same weekday each week.  So if you smelled fish sticks, it was probably Friday.   Here’s how a typical conversation progressed:

Steve:  Hey, Bro, what do you think Mom is fixing for dinner tonight?     

Mike:  It’s Tuesday, Dufus, what do you think?

And Steve immediately realized that they were in for liver and onions. Yuk!

So what’s the unstated premise in my friend’s Eye Care office?

  • If we can get you to pay a charge today, you’ll probably pay it next time without batting an eye.

Unfortunately, they and many others probably DO get away with this deliberately deceptive practice.

As the Romans taught:  “Caveat Emptor!” or let the buyer beware!    

But don’t think that ALL who employ enthymemes are trying to pull the wool over your eyes.

As parents, we OFTEN resort to enthymemes to remind our children of what they already know.

Imagine a typical Saturday morning.  Mom is on her hands and knees cleaning the oven when Johnny tiptoes down the stairs headed toward the front door.     

Mom (who has eyes in the back of her head): And where do you think you’re going, Young Man?

Johnny:  To Billy’s house

Mom:  Is your room clean?

Johnny:  silence….(as he turns around and clumps angrily up the stairs.)

What just got communicated was a truthful and very effective and logical corrective with only one premise (# 2)

Premise 1:  On Saturdays, no one leaves the house until they have cleaned their room

Premise 2:  Johnny hasn’t cleaned his room yet

Conclusion:  Therefore, Johnny is going NOWHERE!

When you have someone employ an enthymeme on YOU, you have every right to ask him or her to articulate the unstated premise(s).Then you can challenge the truth if necessary.

Happy thinking!

Vitamins DO make a difference – creating our first valid syllogism

9 Sep

So, have you taken your vitamins yet?  Are you convinced that some taking of supplements is a habit that improves one’s health?

Last time we set out our conclusion by identifying 2 of the 3 necessary terms.  And we narrowed down our quantifier to SOME vitamin taking, not ALL.

Today we need to finish fleshing out the syllogism by adding a 3rd term.

You will most likely think that our syllogism doesn’t communicate a strong and complete case in support of the conclusion.  You will be right!  This syllogism is just a 1st step.  The 2 premises that we write will simply show your thinking process, how you are arriving at that first conclusion.  An entire argument involves a series of syllogisms.  By focusing on just this ONE LITTLE step, we are staying ‘ honest’ in our reasoning.        

Think about Math Teachers whose litany rings in our memories, “You must show ALL your work to get full credit!”  

Here is our conclusion from last time, properly labeled:

I statement – Therefore, some taking of supplements (Su) is a habit that improves one’s health (Pu)

By the end of our session, we had established the following information about our syllogism:

  • S term of the syllogism (aka Minor Term)  = taking of supplements
  • P term of the syllogism (aka Major Term)  = a habit that improves one’s health

Today we have to come up with our 3rd term (Rule 1), which will be the M or middle term.  This term will LINK the other two terms (major & minor terms), enabling a conclusion.

After playing around with some terms to determine the IDEAL one, I think I found the one that can link the other ideas.  What we are talking about are those daily activities that make a difference in one’s health.   Thus I chose the following for a Middle Term:

Doctor-endorsed daily practices

Next I had to choose the affirmative quantifier.  Did I intend the term to be UNIVERSAL as in ALL or particular as in SOME?

For argument’ s sake, let’s suppose that I happen to think that ALL doctor-endorsed daily practices are habits that improve health (we’ll talk about TRUTH later)

Here is what our syllogism looks like:

All  doctor-endorsed daily practices (Md)  are habits that improve one’ s health (Pu)

Some taking of supplements(Su)  is a doctor-endorsed daily practice(Mu)

Tf, some taking of supplements (Su) is a habit that improves one’s health (Pu)


Let’s go through our checklist to see if the syllogism is at least valid.  Remember that we haven’t even addressed the truthfulness of each premise.

1. 3 and only 3 terms? YES
2. Does the Middle term illicitly show up in the conclusion? NO
3. If a term is distributed in the conclusion, is it Distributed at least one other place NA (both terms in the conclusion are Undistributed)
4. Middle term Distributed at least once? YES (in Premise # 1)
5. Are Premises 1 & 2 negative? NO
6. If Premises 1 & 2 are affirmative, is our conclusion also affirmative? YES
7. If either of the 2 premises negative, is the conclusion also negative? N/A

Therefore, we have written a VALID syllogism!  Yay!

Once you have a valid syllogism, THEN you can look at the truth/falsity of each premise.  But that’s another discussion!

The takeaway?   Those little quantifiers REALLY make a difference.  Be precise with your words.