1. Judgingtherelevanceand
worthofideas,soundnessof
author’sreasoning,and
effectivenessofthe
presentation(Part3)

3. Opinion vs. Argument
• An opinion is a personal claim that
does not necessarily require support
and certain qualities.
• An argument on the other hand is a
claim that needs to be worth making,
valid, sound, logical, and must be
provided with reasonable, relevant,
and sufficient support.

4. Argument
• An argument tries to convince us that
something is true. Keep in mind that an
argument to be considered one has to
consist of: 1) conclusion and 2) premise.
• The conclusion is the idea we are
convinced to believe, and premise is the
support or reason showing that the
conclusion is true.
• An argument may be supported with
more than one premise.

5. Argument
• The boy’s argument can be analyzed this
way:
Conclusion Premise
“Social media
platforms bring a lot
of benefits…”
“…because it makes
communication and
information
dissemination a lot
easier.”

6. Argument
Conclusion
Indicators
Premise Indicators
therefore, hence,
implies that,
it follows that, so,
thus, consequently
Cosince, for, given
that, for the reason
that,
because, as, is shown
by the fact that

7. Argument
• The best kind of argument is one that
is not just VALID, but also SOUND. It
is valid if the premise logically
supports the conclusion. It is sound if
the argument is valid and if the
premise and conclusion altogether
can be verified true.

8. RecognizingLogical Fallacies
Alogicalfallacy isamistakein
logicalthinking;it isaMENTAL
TRAP

9. Looking at the Negative Space
• We can learn muchabout
logic by studying that
which is not logical—
examples of where logic
breaks down, logical
fallacies.

10. Remember: Arguments formed
using fallacies may be valid, but
they are NOT sound!

11. 1
.Hastygeneralization
• Making assumptions about a whole group or range of
cases based on a sample that is inadequate or not
enough
• ✓ Do not make a claim and say it is true if only based on
just an evidence or two.
• Examples:
• 1. Librarians are quiet people and disciplinarians. (This is
an example of stereotyping or over-generalization.)
• 2. My roommate said her philosophy class was hard, and
the one I’m in is hard, too. I warn you, all philosophy
classes are hard! (Two people’s experiences are, in this
case, not enough to base a conclusion.)

12. 2. Faulty Causal Relationship
(also called Post Hoc)
• Stressing that two events or concepts are
related in the sense that one causes another
when they’re actually not
• ✓ Do not assume the cause-and-effect
relationship between two concepts or events
without considering other factors.
• Examples: 1. It was cloudy this morning, so
Sarah did a “sun dance” and it did not rain.
(The sun dance may not have been the
reason for the rain not coming.)

13. 2. Faulty Causal Relationship
(also called Post Hoc)
• Def. To excuse an action or belief by making itsound
sensible. Often this assumes that anything that came
before an event caused it to happen.
• Example:
– I stole the towel from the hotel. They expect people to take
them.
– Eating 5 energy bars and drinking 2 Cokes helps me getbetter
grades. I did this and got an A on my historytest.
Fix this by examining the relationship between ideas. Make
sure the facts precede the theory and the reasons precede
and cause the belief.

14. 3. Slippery Slope
• Claiming a sort of chain reaction will take place,
usually ending in some dire consequence, but
there’s really not enough evidence
• ✓ Do not slide all the way down or exaggerate in
picturing the consequences attributed to a
particular event.
• Example: 1. “Animal experimentation reduces our
respect for life. If we do not respect life, we are
likely to be more and more tolerant of violent acts
like war and murder. Soon our society will become a
battlefield in which everyone constantly fears for
their lives. It will be the end of civilization. To

15. 3. Slippery Slope
• Claiming a sort of chain reaction will take place,
usually ending in some dire consequence, but
there’s really not enough evidence
• ✓ Do not slide all the way down or exaggerate in
picturing the consequences attributed to a
particular event.
• Example: 1. “Animal experimentation reduces our
respect for life. If we do not respect life, we are
likely to be more and more tolerant of violent acts
like war and murder. Soon our society will become a
battlefield in which everyone constantly fears for
their lives. It will be the end of civilization. To

16. 2. Arguing in Circles
• Def: Supportinganopinionnotwithevidencebutwith
thes
a
m
eopinion,slightlydisguised(restatingthe
argumentindifferentwords).Usingthewordyou’re
defininginthedefinitionisaclassicexample.
• Example:
– Educationisimportantfor kids,sotheyshouldgetan
education.
– Everybodylikesicecreambecauseit islikedbyall.
– “Belligerently”m
e
a
n
sinabelligerentway.
Fix it by making sure you are giving support,
not just repeating the idea. Never use the
word you’re defining in the definition.

17. 3. Black & White Thinking
• Def. An opinion that claims there are only
two alternatives (when there might be more)
• Examples:
– You’re either for it or against it.
– Are you a jock or a nerd?
Fix this by remembering that the world is a
complicated place and that on most issues
there are many alternatives.

18. 4. Red Herring
• Def. Presenting an irrelevant topic to divert
attention away from the original issue.
• Also known as Ad hominem: getting
personal as you discredit someone.
• Examples:
– What do you know? You’re just a kid.
– I got an F. Mr. X hates me.
Fix this by staying focused on the topic;
watch out for those who don’t.

19. 5. Loaded Questions and
Statements
• Def. A question or a statement that
conceals an opinion or assumption.
• Examples:
– Do you still beat your dog?
– You don’t think that, do you?
– All intelligent people agree that …
Fix this by listening carefully and
separating fact from opinion.

20. 6. Statistical Fallacies
& False Authority
• Def. People usually believe in numbers and experts
without questioning them. Here statistics are used
to misrepresent rather than describe.
• Examples:
– 3 out of 4 dentists prefer Crest. (Did Crest pick thedentists?)
– I surveyed 100 people and they all agreed with me. (I chose my
friends).
– Dr. X says this is the fastest and safest way to lose weight.(Did
he/she get paid? Where do they practice?)
Fix this by analyzing the evidence. Where did the support come from?
Is there self interest involved? Did you get the whole picture?

21. 8. Misleading Comparison
• Def. Mistakenly believing that two
situations or people can be compared.
• Examples:
– Jill looks good in red. I’ll buy red pants, too.
– Forcing students to read books is like herding
cattle to slaughter.
– You gave him extra time on the test, so Ishould
get extra time too.
– Saddam Hussien is Hitler.
Fix this by remembering that every person
and situation has different

22. 9. Bandwagon
• Def. Lots of people do this, so you should,
too.
• Examples:
– Adults are smoking, so it is ok to do so.
– The American people do not stand for . . .
Fix this by making decisions based on facts,
not popularity.