Transcript BBI 3420 Critical Reading and Thinking

BBI 3420
Critical Reading and Thinking
Critical Reading Strategies:
Identifying Arguments
 Critical thinking is primarily about the
evaluation of arguments.
 Definition of an argument:
1. a set of statements of which it is claimed
that one of those statements (the
conclusion) is supported by the others (the
premises).
2. a reason or reasons offered for or against
something
 ARGUMENT = CONCLUSION (assertion)
+
PREMISES
= THESIS STATEMENTS
+
SUPPORTING DETAILS
Deductive Reasoning

Deductive reasoning starts with a principle
or accepted fact i.e. “all dogs are mammals”,
and then tries to apply this principle to other
specific pieces of information or cases.

Example:
All dogs are mammals.
Fido is a dog.
Therefore, it is true that Fido is a
mammal
 A deductive reasoning is an argument in
which it is thought that the premises provide a
guarantee of the truth of the conclusion.
 In a deductive argument, the premises are
supposed to be a definitive proof of the truth
of the claim (conclusion) i.e. if the premises
are true, it would be impossible for the
conclusion to be false.
 1. All men are mortal. (premise)
2. Socrates was a man. (premise)
3. Socrates was mortal. (conclusion)
 Deductive reasoning leads to nonnegotiable conclusion.
 The goal is not to generate new
information.
 Some dictionaries define "deduction" as
reasoning from the general to specific
Inductive Reasoning
 An inductive argument is one in which the
premises are supposed to support the
conclusion in such a way that if the premises are
true, it is improbable that the conclusion would
be false. Thus, the conclusion follows probably
from the premises and inferences. Here is an
example:
 1. Socrates was Greek. (premise)
2. Most Greeks eat fish. (premise)
3. Socrates ate fish. (conclusion)
 Inductive reasoning begins with several
pieces information, several observations,
or examples and tries to arrive at a
general pattern, tendency, or trend
(hypothesis).
 There is always the hope that by
discovering what is true for some
members of a group, you will discover
what is true for all members, but there is
no guarantee.
 Inductive reasoning is often perceived as discovery
learning.
 Examples:
The members of the Williams family are
Susan, Nathan and Alexander.
Susan wears glasses.
Nathan wears glasses.
Alexander wears glasses.
Therefore, all members of the Williams
family wear glasses.
Identifying the conclusion
 An argument's conclusion is what the person
making the argument is ultimately trying to
convince you of, i.e., the person's point.
 To try to identify the conclusion of an argument
ask yourself 'what does the person making the
argument want me to walk away thinking?' (Note
if the answer is 'nothing', them you're not dealing
with an argument.)
Some Conclusion Indicator
Words:
 To identify conclusion, it often easiest to
look for conclusion indicator words, such
as:
therefore, consequently, as a result, thus,
it follows that, so
Identifying the Premises
 Every argument must also consist of at
least one premise.
 A premise is a statement that is meant to
support the conclusion. Ideally, a premise
provides a good reason for believing the
conclusion.
Some Premise Indicator Words:
 To identify premises, it often easiest to
look for premise indicator words, words
that are often used to introduce a claim as
a premise such as: because, since, as,
for, given that
Missing Premises and
Conclusions:
 When trying to figure out what the premises and conclusion
of an argument are, we need to ask ourselves what the
person's point is.
 But remember that people don't always come out and say
what their point is. Similarly people may not always
explicitly mention all the premises they are working with.
 As a result, we must be prepared to identify both missing
premises and missing conclusions (i.e., conclusions or
premises that are not explicitly stated by the arguer, but
that are implicit in what the arguer does say).
Another way to identify
components of arguments:
 Every conclusion must be a proposition.
Every premise must be a proposition. As
such, every argument must contain 2 or
more propositions.
My cat has fleas.
Obama will win the next election.
 Propositions are the building blocks of
arguments. A proposition is any phrase
that can be true or false. The first step in
analyzing the components of an argument
is to identify the propositions.
Finding Propositions
 Every proposition will contain a predicate
(a verb phrase). As such, the best way to
identify a passage’s propositions is to look
for the verbs.
 For example:
 “Athletes are not good role models. They
often behave poorly and many do not
complete their education. Therefore they
should not be paid as much as they are.”
 The propositions of the previous passage:
1. Athletes are not good role models
2. They often behave poorly
3. The do not complete their education
4. They should not be paid as much
 To determine whether or not two or more of the
propositions on your list are related as premise
to conclusion (and thus form an argument) plug
the propositions into the blanks on the following
test:
Conclusion/Premise tester:
___________________because ___________
 The first place is the conclusion slot and the
second place is the premise slot:
Conclusion because Premise
Example:
They should not be paid as much because
athletes are not good role models