Logic and Communication
Foundations in Professional Communication (FDCOM 201)
Fall 2008 pilot
Ryan DaBell, chemistry
Welcome to the Logic and Communications unit of FDCOM. By now, you have discovered that much of
the “content delivery” in FDCOM is done online—and this portion of the course is no exception. In this
unit, we hope to accomplish three goals:
1. We will review logical arguments and understand basic terms associated with logical arguments
2. We will identify and analyze basic logical arguments and fallacies in scriptural and modern
examples.
3. Finally, we will use these skills to analyze and correct arguments that are made in course
assignments and in future communications of all kinds.
Most of this unit’s materials stems from readings written by Prof. Robert Worrell of the BYU-Idaho
English department, and by Jesse Ellsworth, a BYU-Idaho student (as of Summer 2008). You will also
read a contemporary editorial on a subject of current interest in society. This article will be discussed in
your study group, and also possibly in your section (depending on the individual professor). Additional
resources will also be suggested for further study in the areas of logic at the end of the unit.
Well, let’s get started.
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I.
Logical arguments: basic terms, definitions, and usage
It’s a good idea to remember some of the basic terms associated with logical arguments, fallacies, and
other “tools” that we will be using in this unit. Some of these terms you will have encountered during
the Foundations in English (FDENG 101) class, but a review will be beneficial.
a. Definition of “argument”
First off, let’s remember what the definition of a logical argument is. And, to help do that,
there’s nothing like an old Monte Python skit. (“But of course”, you say.) Click here to access a
clip from “Monte Python’s Flying Circus”. Afterwards, take a few minutes to answer the
following questions. Record your responses in your course journal:
1. What is an argument?
2. How does an argument differ from contradiction?
3. The scriptures instruct us to avoid “contention” (3 Ne. 11:28). Can one have an “argument”
without be contentious? Try to recall an experience where this may have happened in your own
life.
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b. Basic argument terms
Next, we want to review some basic terms regarding logical arguments. Read the first set of
excerpts from Bro. Worrell’s essay “Truth is Reason”, and from Jesse Ellsworth’s essay “Logic
and its Fallacies”.
[from Ellsworth]
We often hear the statement that something “is logical”. What does it actually mean to be logical? In
this short introduction to logic you will learn just what that means, and how to avoid the many pitfalls
that will lead to the illogical.
Logic itself is the study of the formation of ideas and arguments. (Arguments in this sense do not entail
yelling back and forth; instead arguments are the compilation of statements that give evidence or
foundation for one another, and often lead to a sole conclusion) The study of logic is based on both
inductive and deductive logic.
Inductive logic is the ability to take ideas that if true would lead to the conclusion desired. One of the
least common examples of this comes with the ideas that if the moon is made of green cheese, and
humans need to eat, then astronauts, who are human, don’t need to take food to the moon. Now, we
know that the moon isn’t made of green cheese, but if it was they wouldn’t need food. Inductive logic is
the logic of probability. From what I know of premise A and premise B my conclusion is either very
probable or not likely. This is the logic of science. Because I know the law of gravity and I know that I
have an apple which is subject to the law of gravity, I can argue that if I let the apple go, it will fall to the
ground. I can never have absolute certainty with induction, but my probabilities can be very high – the
higher the probability, the stronger the argument.
Deductive logic is actually the way of proving the absolute truth of a statement. It shows that if what is
said in the premises of the argument is true, then the conclusion must be true. This would be better
solidified in an example: if the computer is new, then it would cost a lot of money, the computer is new,
therefore it cost a lot of money. Now, if the first two statements statements that make up the argument
are true, then the conclusion must also be true, and the computer would cost a lot of money. It is
therefore important to find out if our statements are true, and to make sure that we compile them into
a logically formed argument. A logically formed argument is called a valid argument. An argument can
only be valid if the form of the argument is as such that if the premises are true, then the conclusion
must be true. The most famous valid argument has the form:
If A, then B
A
Therefore B
Just looking at the form, you know that the argument is valid. The next step in a deductive argument is
to find the truth of the premises. If we have a valid argument, and we see that the premises are true,
then we call that argument sound. It is the finding of truth that we must now look into.
In order to justify our beliefs and form them correctly, there must be a criterion upon which the
discussion may be based. By deciding whether arguments are strong or weak (inductive logic) or sound
or unsound (deductive logic) you are then able to decide what value they can play in your own personal
arguments. By looking at some of the major needs of these arguments, you will see how to form your
own arguments and then find what things are needed to strengthen them.
Of course the first thing we need is the ability to understand the argument itself; this must be the
principle criterion of an argument. An idea that is not clear in word and in concept cannot be fully
understood or fully developed – let alone complied with or argued against. Without a clear
understanding of each of the ideas that compose the whole argument, it can be difficult or near
impossible to discuss the point that is being made by the arguer. The call for clarity in the words,
phrases, ideas, and arguments is the most necessary step in understanding the works of others and
presenting your own ideas. By ensuring that each part of your argument is clear, the overall effectives
and strength of your claim will be enhanced.
[from Worrell]
For this occasion, I will focus on just one of the areas I have learned as a student of language. That area
of scholarship is formal logic. Interestingly, I have been acquainted with some academicians who laud
scholarship but avoid formal logic with the same care they take to avoid salmonella poisoning. The
contention is that they can “sense” when an argument is right or wrong, and they do not need to be
encumbered with all of the tools and paraphernalia. That reasoning is similar—or parallel—to that of
some artists who discount the work of illustrators and graphic designers as “non-art” because they take
the time to lay out and measure their designs before they begin. “Real art,” apparently, just happens,
somewhat like spontaneous combustion.
I am not creative enough to believe that logic just happens. I am all left brain and no right, which
probably accounts for my attraction to formal logic. Things ought to make sense. Truth ought not to
contradict itself or change with the shifting of the wind. Bruce R. McConkie happens to agree with me
on these points. He writes:
Truth is absolute and eternal; it endureth forever (Doctrine and Covenants 1:39; 88:66; Psalms 100:5; 117:2). It never varies;
what is true in one age is true in every age. The theories of men (scientific or otherwise) vary from discovery to discovery and
are in a continuing state of flux, unless they chance on a particular point to reach ultimate truth. Then there is no more change,
and the truth discovered is in complete harmony with every other truth in every other field. Truth never conflicts with truth.
Truth is not relative; it is absolute. What is true in one eternity is true in the next. The knowledge men have of the truth may be
great at one time and slight in another, or the reverse, but the quantity of ultimate truth is neither added to nor diminished
from by revelations received or discoveries made.1
Those who accept this definition of truth, and then define scholarship as the search for truth, can say, in
fact, that scholarship is their theology. Unfortunately, not all ideas advanced in the name of scholarship
fit into the category of truth, so the sincere scholar needs a means to sort out ideas worth keeping. As
the Apostle Paul said: “Prove all things; hold fast that which is good” (1 Thessalonians 5:21).
So, the apostle counsels, “Prove all things.” To prove is to establish the truth and validity of an idea by
the presentation of argument or evidence.
Formal logic is a tool for knowing, not guessing, whether an argument is valid. It is also a means for
exposing all the premises of an argument, many of which may only be implied, and subjecting them to
evaluation in an attempt to determine their truth. It requires a bit of effort, but it has its rewards.
Any sound argument must be both true and valid. An argument is true only if all of the premises and the
conclusions connected with it are true. Sometimes it is fairly easy to determine the truth of an assertion
used as a premise or drawn as a conclusion. One such assertion is:
All human beings require oxygen to survive.
Other assertions may defy proof or disproof by empirical data. As an example, consider the following:
Adolf Hitler lived in Argentina from 1945 until his death in 1987, at age 98.
Instead of proof, such statements can be given a plausibility rating. Considering all the existing
information on the subject and the credibility of the sources of such information, one can reason out,
with the use of logic, just how likely it is that the statement is true. That is helpful in forming further
conclusions, although such conclusions remain theory and are not fact.
[Note: Br. Worrell has just described an example of inductive reasoning. Such reasoning allows one to
draw conclusions that are likely to be true, based on the current evidence available. Scientific theories
are conclusions based on inductive reasoning. Deductive reasoning, on the other hand, leads to
conclusions that must be true if the premises are true. Read on…]
An argument is valid (though not necessarily true) if it is structured properly so that the conclusion can
be drawn reasonably from the premises. The following argument is valid:
All green apples are sour.
This apple is green.
It is sour.
Changing the structure of the argument, as in the next example, makes the argument invalid. In other
words, the conclusion drawn is not based on the premises.
All green apples are sour.
This apple is sour.
It is green.
These are simple concepts and easy to remember. Applying them to the material one normally reads
can enhance perception.
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A quick review
Which of the following represents a valid argument? Read carefully, as there might be more than one
correct answer. You’ll receive feedback on your selection after making your choice.
Mammals breathe air and nurse their
young.
Sperm whales breathe air and nurse
their young.
This is a valid argument; its conclusion agrees
with the premise.
Sperm whales are mammals.
All carrots are vegetables.
Broccoli is a vegetable.
Broccoli is a carrot.
This is an invalid argument; the conclusion
“broccoli is a carrot” does not agree with the
premise “all carrots are vegetables”—because
there may be vegetables that are not carrots.
All vegetables are carrots.
Broccoli is a vegetable.
Broccoli is a carrot.
This is a valid argument. The conclusion this
time agrees with the premise “all vegetables
are carrots”. However, the premise is false.
That means the argument is not sound, but it
is valid.
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It is important to recognize that an argument can be valid and yet not speak the “truth”, because its
premise is false—such are called unsound arguments. When looking at different viewpoints in society,
we will frequently encounter these arguments—whether they seem to be sound arguments will depend
on how you view the premises.
A good example might be found in the claims of some that members of the Church of Jesus Christ of
Latter-day Saints are not Christians. Many who claim this base their conclusion on premises such as, for
example, a belief that the Bible is inerrant. So, their argument looks like this:
Christians believe the Bible to be the inerrant word of God. (premise)
Mormons believe the Bible to be the word of God only as far as it is translated correctly, that is, they do
not believe it is “inerrant”.
Mormons are not Christians. (conclusion)
The argument is valid. However, it is based on a premise which LDS Church members would generally
find incorrect; therefore, we would say this is an unsound argument. On the other hand, those who
make the argument, believing the premise to be correct, hold this to be a sound argument. When we
realize that our differences are based on deeply held assumptions, rather than faulty reasoning, it is
easier to understand and respect each other’s differences, even if these differences might not be fully
resolved.
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c. Fallacies
Jesse has put together an excellent set of fallacies that are commonly encountered. Read this excerpt
from his essay before continuing.
The other aspect of logic that we need to address at this point is how to avoid many of the fallacious
statements in argument you present.
Though logic helps with the basics of the foundation and formulation of arguments, there are
many other aspects to logic that are quite beneficial. One of the major benefits of logic comes from
being aware of and avoiding many of the common informal fallacies. These fallacies are those logically
inconsistent statements in an argument. By realizing these and avoiding them in your own arguments,
you will build stronger arguments and, by being able to see their use in the arguments of others, will see
the strengths or weaknesses of many other arguments. The following informal fallacies are commonly
used and should be prevented at all times.
One of the fallacies dealing with the clarity of your argument is called Equivocation.
Equivocation is when the same word is used in two different meanings in the same argument. This can
be very hard to catch during a heated debate, and for this reason, it is often used by politicians. Notice
how I use the same word “nothing” in two different ways to prove my radical conclusion:
Hot dogs are better than nothing
Nothing is better than steak
Therefore, hot dogs are better than steak
The form of the argument is valid. It states that:
A>B
B>C
Therefore A>C
The problem comes when I equivocate my terms. This is argument is not sound.
A common type of logical fallacy though not commonly noted is that called Ad Baculum, this
arguments name comes from Latin meaning the argument from the stick. This type of argument is often
referred to as an appeal to force, where the person giving the argument is trying to use harmful or
threatening outcomes to validate their own statement. An example of this would be:
The moon is made out of green cheese, and I know it because anyone who disagrees with me will get
punched in the face.
It is obvious that the reasoning for why the moon is made up of green cheese has no real basis, but if
you are scared of the person who has given the argument, or bleed easily, maybe you will agree just the
same. The fallacy of ad baculum is not based on logical conclusions, but only on fear, pain, or possible
recourse from the deliverer of the idea.
Another fallacy whose name stems from Latin is the fallacy of Ad Hominem, which means the
argument against the man. This fallacy is one that does not deal with the points made in any major
aspect; instead the argument is one that attacks the person giving the argument. This fallacy is actually
broken down into multiple types the abusive, the circumstantial, and the tu quoque. All of these attack
the person in differing manners either the person themselves, their circumstances or situation, or even
their own actions respectively. In all though there in not a true proving against the argument. This
fallacy is actually quite common, and is practiced in law and politics today to show that the person’s
weak character cannot be trusted, and so what they say not matter how true cannot have any strength
either. An example would be:
John beat up his friends yesterday, so because John is mean he doesn’t believe that God exists.
Ad Verecundiam(appeal to authority) can be broken down to explain the fallacy of an argument
that appeals to an unreliable authority. In this fallacy the arguer will give the foundation of the
argument due to the credibility of another. This is not in itself wholly an unintelligent step, but it must
be done with competent accreditations. By stating that the moon is made of green cheese because the
space program has a piece of green cheese from the surface of the moon, and that it is documented by
them would be a good use in that argument. Instead, stating that:
Joe, who wants to punch people who don’t agree about the moon being made of green cheese, says
that the moon is made of green cheese, and I believe him.
would not be a good, credible source for your argument about the moon’s material makeup.
Appealing to Ignorance is a fallacy that is founded upon the inability to prove otherwise. When
an argument is made, the lack of knowledge or evidence is suppose to prove the point being made. This
conclusion shows that the argument must be true only because there is nobody there that can prove to
you that it isn’t that way. If one was to say
The moon is made of green cheese, and that is true because you cannot prove it isn’t.
This doesn’t actually prove the truth about a green cheese moon at all. This argument which is also
often called ad ignorantium can be seen commonly in the debate about God, either God exist because
you cannot prove he doesn’t, or God doesn’t exist because you cannot prove he does exist. Both of
these are completely fallacious arguments about God’s existence.
Arguments that are self dependent also make up a section of fallacious statements, these are
those based upon what is called circular reasoning. Circular reasoning is defined when the premises or
statements of the argument are based or founded upon the conclusion. Because the statements and
the conclusion give strength to each other, or prove each other they cannot be considered to give basis
for one another, and so the argument has no foundation. A common example in religion for God’s
existence is,
The Bible states that God exists, and the Bible is true because it comes from God.
This argument is, of course, shaky because the Bible’s truth is dependent on God’s existence, and God’s
existence is based on the Bible’s truth. The fallacy from circular reasoning, also called begging the
question or the Latin petitio principii, can be difficult to spot for it requires a good understanding of the
argument and the principles being involved - especially in longer thoughts or arguments.
Application of information is definitely important when constructing an argument or idea. The
way in which this is done can be a great strength overall, or it can weaken an argument and constitute
another fallacy. These fallacies are of two kinds. The first of which is the fallacy of composition, which
states that what is good for one part is good for the whole. By stating that the idea or attribute from
one must therefore apply to all does not logically proceed. This may be better understood with an
example:
Jane has an A in philosophy, and because Jane has an A everyone in philosophy has an A.
Now it might be that everyone does have an A in philosophy, or at least that everyone wants an A, but
that does not come just because Jane has an A.
Assuming that the part applies to the whole is the fallacy of composition, the converse of this is
the fallacy of division. This states the opposite of course that what is true for the whole can actually be
applied to each piece of that whole. By applying this back to philosophy class you can see that it does
not work either:
The class average in philosophy is a B, therefore everyone in philosophy has a B.
This of course is not likely to be true, though there is a small possibility that everyone in class has the
exact same grade in all realistic ideas they do not. The average grade cannot be given to all instead it is
the compilation of all grades. By applying an aspect of the whole to each part of that whole also does
not work.
Alternatives can also be causing the possibilities for fallacious statements. Two major of these
are the fallacy of false dilemma and the fallacy of false cause. The first the fallacy of false dilemma
states that there are only a certain amount of outcomes that can arise from the previous arguments
made. This limiting of the alternatives does not effectively show all of the possibilities that can be
considered. By returning to our examples about the moon we can find an example. In the following
statement we see the fallacy of false dilemma:
Either the moon is made of green cheese or the moon is made of swiss cheese. But there are no holes
through the moon. Therefore the moon is made of green cheese.
There are many other materials that could contribute to the moon’s composition, namely sediments,
water, ice, wood, or anything else. Limiting the options without cause places the argument into the
realm of the fallacy of the false dilemma. The fallacy of false cause arises when we decide that because
one action happened and another followed that it must have caused the first. An example would be:
Because my alarm goes off just before the sun rises, my alarm clock makes the sun rise.
That, of course, is absurd, but that is the fallacy of false cause.
Anciently knights would practice their tactics against dummies made of straw. The next fallacy
is called the straw man argument, and can be seen in the same light. Just as the fighting of the straw
dummy is much easier than an attacking foe, attacking a straw man argument is a fallacy in which the
true argument is not attacked. Instead the argument is diminished and reduced to a weak form not
presented and then shown to be false. By attempting this fallacy it only shows the inability of an arguer
to combat the stronger and truly presented form of the argument. The other method of falling into this
fallacy is to attack a conclusion not named in the argument, and considering such an act to bring down
the whole argument itself. A good modern example of a popular modern day straw man is the following
statement:
Evolution says we all came from monkeys.
Evolution doesn’t quite claim that “we all came from monkeys.” It is however, easier to argue
against something that most people would find offensive or silly.
One of the more interesting fallacies is a type of Non Sequitur called a red herring. The point of
the fallacy is to throw something into the argument that will blind the opposition to what is really being
argued. The red herring has nothing to do with the conclusion or the argument in general, but is
nonetheless thrown in:
Susan : You said “yes”? You've only known him for two weeks! Are you insane?
Clair: I had a good feeling.
Clair's feelings have nothing to do with Susan's question of sanity. Even people who are insane are
thought to feel good. It could be argued that Clair meant she had some spiritual confirmation, and that
makes everything good. However, the fact remains that even a spiritual experience has nothing to do
with the question of sanity. It can be supposed that many people who are insane have “spiritual”
experiences.
At last we find the fallacy called wishful thinking. This is quite common as fallacies come and are
set upon desires instead of logic. In this fallacy we agree with the argument or its conclusion because
we want it to be right, not because it is right. Though the claims of the argument may be completely
false, we instead overlook the inaccuracy of the argument in hopes that it is true:
We don’t have enough food on this planet anymore, so if the moon isn’t made of green cheese, we
are all going to starve. Therefore the moon must be made of green cheese.
True or not, the desires and fears that we have cannot make up for the lack of logic in the argument.
Although, avoiding these fallacies will strengthen the arguments you make and also the ideas
you propose, they will not lead you to have correct, indisputable ideas. Instead, they will give you a
base on how to beat many of the pitfalls of reasoning and help you to craft ideas that are much more
usable. By applying these principles against fallacies and the aforementioned ideas on argument
construction, the philosophical world will be more open, and the way in which you interpret the many
arguments you read will be enhanced.
After Jesse’s introduction, you’re ready to read the next selection from Br. Worrell’s article. Br. Worrell
will take us through the debate between Amulek and Zeezrom, illustrating the crafty use of fallacies by
Zeezrom to strengthen his own position in front of his audience.
Obviously, both Zeezrom and Amulek are presenting arguments to establish their points of view. First,
Zeezrom tries to show a contradiction in Amulek’s statements. Amulek says there is only one God; yet
he says the Son of God will come, and one God plus a Son of God makes two Gods. Zeezrom urges the
people to remember this against Amulek.
Further, Zeezrom accuses Amulek of saying that the Son of God will not save his people. Zeezrom just
omits the phrase, “in their sins.” Leaving it out changes the argument, making it a great deal easier to
disprove. Altering an argument to make it vulnerable to attack is known as the straw man fallacy.
Then Zeezrom argues that, by saying this, Amulek speaks as though he had authority to command God.
One might paraphrase Zeezrom’s statement this way: “Amulek, you speak as though you have authority
to command God because you say His Son will not save his people.” Even if Amulek’s statement were
incorrect, that does not mean he is claiming authority to command God. Zeezrom draws a conclusion
that in no way relates to the premise, thus committing the fallacy of non sequitur.
Counting his misrepresentation of the Godhead [one God plus a Son of God makes two Gods], Zeezrom
commits at least three logical errors in one sentence. Most of my students can’t do that. It takes some
effort and a bit of understanding to create an argument as compact and subtle as Zeezrom’s, and it
seems clear that he uses the fallacies intentionally. Alma sees that Zeezrom “beheld that Amulek had
caught him in his lying and deceiving,” and being exposed made Zeezrom “tremble under a
consciousness of his guilt.”
Amulek responds by first pointing out the non sequitur. A paraphrase of his answer might read:
“Zeezrom, you lied because you said I spoke as though I had authority to command God just because I
said he will not save his people in their sins. In other words, you drew an incorrect conclusion from the
premise.” At the same time, Amulek corrects the straw man fallacy by reinserting the phrase, “in their
sins.” He does this in verse 36, but he waits until verse 44 to clear up Zeezrom’s misconception of the
Godhead.
[Note: verse 44 reads, in part, “ …every thing shall be restored to its perfect frame, as it is now, or in
the body, and shall be brought and be arraigned before the bar of Christ the Son, and God the Father,
and the Holy Spirit, which is one Eternal God,…” (emphasis added), countering Zeezrom’s “1 God + 1 Son
= 2 Gods” argument.]
In verse 37, however, Amulek presents an argument to establish the true doctrine of the atonement.
Structured in the form of logical syllogisms—each of which has a major premise, a minor premise, and a
conclusion—it reads thus:
No unclean thing can inherit the kingdom of heaven.
A person with sins is unclean.
A person with sins cannot inherit the kingdom of heaven.
You must inherit the kingdom of heaven to be saved.
A person with sins cannot inherit the kingdom of heaven.
You cannot be saved in your sins.
These two linked syllogisms are valid. All of the parts are in the right place, and the conclusion, in each
case, logically follows the premises. They are linked together because the conclusion in the first
argument becomes the second premise in the second argument.
Amulek establishes the truth of his premises by taking them from the scriptures and asserting that the
scriptures are the word of God. He says, essentially, “God said this, and I cannot deny his word.”
In just three short verses, two complete arguments face off against each other. The argument of
Zeezrom is full of logical fallacies and is easily torn apart. The argument of Amulek is perfectly structured
deductive reasoning. So how does this bit of scholarship inform my theology?
Probably a person could make a number of inferences, but the one I make is this: Joseph Smith did not
write these arguments. Alma, an eyewitness, wrote them in his journal, and Mormon copied them onto
the plates. Considering the difficulty of making up such a compact debate and then giving the bad guy all
the fallacies while the good guy uses perfect logic, and even does it by asking rhetorical questions; I say
again that Joseph Smith, with his limited education, did not compose that text. Of course anyone who
wishes to prove me wrong may take the Lord’s challenge in the Doctrine and Covenants:
Now seek ye out…even the least [revelation] that is among them, and appoint him that is the most wise among
you;
Or, if there be any among you that shall make one like unto it, then ye are justified in saying that ye do not know
that they are true;
But if ye cannot make one like unto it, ye are under condemnation if ye do not bear record that they are true.
(Doctrine and Covenants 67:6-7)
You’re just about to the end of this little section. Before taking the final pre-class quiz, consider the
following questions. Write the answers in your journal.
1.
Think about the last time you had a confrontation with a spouse, friend, sibling, parent,
roommate, etc. Did either of you use any fallacies in your argument? Can you identify any?
2. In the text “Crucial Conversations”, you have been reading about the problems that “silence”
and “violence” pose to establishing meaningful conversations. How do you think using rational
arguments might reduce the chances of the conversation turning ugly?
3. Can a rational argument alone convince others to act? What else may be necessary?
4. In a quiet place, consider some of your favorite scripture passages. Are any of the principles of
logic discussed in this unit evident in those passages? If so, how do the logical arguments help
you understand the doctrine in those passages?
Congratulations! You’ve reached the end of this section. I hope this unit has been useful for you in
reviewing the basics of formal logic. Even though many of our examples have been taken from
scriptures (or the composition of the moon), the same logical arguments and fallacies are found in
contemporary writing. In most sections, your next study task will be analyzing a contemporary article
dealing with a controversial topic in modern society, preparatory to discussing it in your study group and
in class. If you apply what you have learned here, it will be all the easier for you to break down the
writer’s arguments and analyze them for validity, soundness, and strength.
There will now be a short, 10-question multiple-choice quiz. You will have 15 minutes to complete the
quiz for credit. Click here when you are ready to take the quiz.