Critical Thinking
Helvetica font
underlined (Related to future quiz)
Week 1 Lecture
Monday 1/12
What is critical thinking?
What is the definition of “Critical”: Expressing adverse or disapproving comments or judgement. (google search); Seeing a situation and finding out the different paths that it presents.
What is the etymology of “critical”: Greek root krinein which means to judge or discern
How to tell the difference between things and get clear about why they’re different. Whose discernment is this? Who gets to set the parameters of proper judgement? There are many ways in which our judgment is simply that of our society’s culture’s. How do we break free from that?
Definition of “thinking”: The process of using one’s mind to consider or reason about something. But was is reasoning? The weighing of differences and likenesses to make a well supported conclusion.
Etymology of “thinking”: To see to appear, imagine, conceive in the mind, meditate
What would be a good etymology based definition of “critical thinking”: To judge or discern what seems to appear in our mind
What is an argument?
It is a set of at least two propositions, one of which must be the conclusion and the others the premise (dictionary definition).
What’s a proposition? A statement that has a truth value attached to it. It is either true or false. A statement that has a truth value attached to it can be answered with a yes or no, true or false. A proposition is a type of statement. It is a statement, but a statement is not necessarily a proposition.
What’s a conclusion? It is the entire point of the argument that is well supported
What’s a premise? The evidence that allows you to make this conclusion. This process is called an inference.
P= Premise, C= Conclusion,
P1
P2
.
.
Px
evidence
goes to inferential process
//C
//= means therefore so does a triangle with 3 dots
^ The standard form of an argument. It traces the infereital process. When we say, “What do you infer?” We mean to say, “What are the pieces of evidence that allowed you to form that conclusion?” When we do this properly, we can say to have com eup with a justified opinion about a matter.
Wednesday 1/14/2026
The argument in greater detail. A set of statements must show an inferential process if it is to be considered an argument. If it lacks this process of reasoning that tells why the conclusion is the case, it is not an argument. This means that the following are not arguments.
1. A statement that reflects only a report of things. And argument must express an opinion or beliefs, and a pure report simply states facts, not opinions:
2. Not a piece of advice without evidence:
3. Neither is a warning without reasons (especially sign) ;
4. Not a pure elaboration. Again, this is an objective statement and argument are subjective
5. Not pure illustration of something, This again is objective
6. Pure commands are not arguments either
How to recognize arguments and their parts:
Arguments must express the writer’s point of view. Be Careful. Simply stating someone else’s point of view or argument is to report someone’s argument— it is not to give an argument
Arguments are also almost never give in standard form, Most people usually begin with the conclusion, not the premise.
Look for conclusion indicators (p.7). These are words like thus, therefore, consequently, it follows that, so, hence, etc.
Look for premise indicators (p.7). These are words like since, becuase, given that, are shown by seeing that, etc.
PAGE 7 for Quiziz 10 questions 10pts all true/false
Examples pg 11 #2. “If you start a strenuous exercise regimen before you know if your body is ready, you can cause serious damage. Therefore, you should always have a physical checkup before you start a rigid exercise program”
What is in the yellow is purse objective fact— not an opinion Clearly it is not on its own an argument But what’s in magenta is the conclusion indicator. Any complete clause that follows this as a sentence is the argument’s conclusion. The complete conclusions is in the teal highlight.
But this is not the only way you can state the argument. This says the same thing and is still a conclusion- identified by the “Because”
You should always have a physical checkup before you start a rigid exercise program because if you start a strenuous exercise regimen before you know if your body is ready, you can cause serious damage.
Here the premise has been shifted to the end as identified by the premise indicator “Because”
How about this:
You Should always have a physical check up before you start a rigid exercise program. If you start a strenuous exercise regimen before you know if your body is ready you can cause serious damage.
There are no premise or conclusion indicators here. How do we know which one is the conclusion and which one is the premise?
When this happens, use the test: force a conclusion indicator (thus) in front of what you think the conclusion is. Do the same with a premise indicator. (because) and if you’ve identified them correctly, the argument will make sense. If the argument does not make sense —-if it makes no rational inference—then you’ve got it wrong.
Notice that this doesn’t make sense: Because you should always have a physical checkup before you start a rigid exercise program thus if you start a strenuous exercise regimen before you know if your body is ready, you can cause serious damage.
This doesn’t make sense because the reason you start the fact is an explanation before the reasoning. in standard form, this looks like the following
P1 you should always have a physical checkup before you start a rigid exercise program
//C : if you start a strenuous exercise regimen before you know if your body is ready, you can cause serious damage.
There is no rational connection between the premise and the conclusion. We need to flip this around:
P1: If you start a strenuous exercise regimen before you know if your body is ready, you can cause serious damage.
//C: You should always have a physical checkup before you start a rigid exercise program
Here’s another example pg 13
#8. “There is biological evidence that the genetic characteristics for nonviolence have been selected over time by the species, and the height and the weight of humans have increased over the centuries”
Argument or not? Not an argument. It is a set of purported facts.
But given these two objective claims, can an inference be drawn? Yes, But we’d need more information. What does weight and height have to do with violence/nonviolence? Is there correlation between them? If we had more information, we could form an argument.
Example: Height and weight shouldn’t mean much for non violence/violence.This is an example of an opinion/belief, and to state this will require further pieces of evidence that we do not have.
#11 “All living things (plant, animals. humans) have the ability to absorb nourishment, to grow, and propagate. All “living creatures” (animals and humans) have in addition the ability to perceive the world around them and to move about. Moreover, all humans have the ability to think, or otherwise to order their perceptions into various categories and classes. So there are in reality no sharp boundaries in the natural world.” Jostein Gaarder, Sophie’s world.
This is an argument. Here’s how it looks in standard form.
P1:All living things (plant, animals. humans) have the ability to absorb nourishment, to grow, and propagate.
P2: All “living creatures” (animals and humans) have in addition the ability to perceive the world around them and to move about
P3: all humans have the ability to think, or otherwise to order their perceptions into various categories and classes.
//C: there are in reality no sharp boundaries in the natural world.
Take a look at the argument above. Is it good? It does have evidence. But is it good evidence? Do the pieces of evidence assume anything?
Is there an assumption that humans exist differently than animals?
Plants do have an ability to perceive the world around them.
Do animals have the ability to think?
Are the assumptions warranted? In others words, do we have good reason to think that the assumption cannot stand the test of reason> If there are, then the assumptions are unwarranted and while there is an argument, that conclusion stands on questionable grounds.
WEEK 2
We have already gone through the basics of an argument, and you may have also realized that there’s a lot going on with analyzing arguments than first meets the eye. And honestly, assessing arguments can be difficult. Why? Let’s look at some reasons:
A. In general, people in public settings play nice. They do not want to argue. They hedge and
give very vague answers, perhaps as a strategy of self-protection as a way to hide their true
opinion. They don’t want to hurt other people’s feelings, and they don’t want to open
themselves up to strangers. “If I let others know my actual opinion,” so they may say to
themselves, “that may make me vulnerable to verbal attack. I don’t want to be attacked, so
I’m just going to keep quiet about what I actually believe.” The result of this? It’s the "I’m-OK-
You’re-OK approach,” where everyone has the right to their own opinions. And yet some
issues really need a vigorous argument to defend or attack;
B. Some people are really bad at arguing their point. We know what an argument is—it is an
inferential process consisting of a set of at least two propositions, one being the
conclusion, which is the end result of the other propositions that serve as the evidence to
justify that conclusion. They confuse an argument with an opinion simply given with neither
adequate evidence nor good reason; This is true of deductive argument especially
C. Others are aware that evidence must be given to back up their conclusion, but the
inferential process they use does not, in fact, result in the necessary realization of their
conclusion. This is a special case, and we’ll introduce it in a couple of weeks’ time;
D. And yet others assume too much in their argument. Some premises are based on
assumptions that cannot be reasonably held, and there may be premises missing and
assumed to be self-evident;
E. And sometimes the argument is so specialized that we need more information to properly assess it. So a lot of ways arguments can be difficult to assess properly. But the one big clue about dealing with arguments? We’ve talked about this briefly, but it is the fact that giving arguments is something that we already do. Intuitively we know how to make a good argument, so let’s start at the basics with some examples from the book.
1. This is p. 11, #3. “Since television commercials help pay for the cost of programming, and
because I can always turn off the sound of the commercial, go to the bathroom, or get
something to eat or drink, it follows that commercials are not such a bad thing.”
Now this comes from the section where we are supposed to identify the conclusion, so we
know this is an argument. And if we know the conclusion indicators (again, p. 7), we can
easily spot the conclusion: it follows that commercials are not such a bad thing.
And of course this is how it looks in standard form:
P1: Television commercials help pay for the cost of programming;
P2: I can always turn off the sound of the commercial;
P3: I can go to the bathroom;
P4: I can get something to eat;
P5: I can get something to drink.
// C: Commercials are not such a bad thing.
This argument is thus a 5 premise argument. Is it good? Do the premises all lead us to infer
the conclusion? Yes they do, so this is an easy to follow argument. But what’s the problem
with this argument? It is that almost no one ever talks like this.Does this argument have any assumption? Yes it does assumption that you need to use the restroom, have food etc. There is good reason to think that people watch TV where food and drink and a bathroom is near, and that they have control of the TV.
2. Let’s take a look at an example from real life. This is p. 11, #7, and it is the famous quote
from René Descartes, first published in his Discourse on the Method: “I think, therefore I
am.”
Again, if we were to go by the conclusion indicator ‘therefore,’ this is pretty easy: therefore I
am” is the conclusion. It would be easy to put it in standard form:
P1: I think.
// C: I am
One premise, one conclusion. Easy! But the issue now is whether this is a good argument.
Does the premise lead one to infer the conclusion? At first, no. What connects thinking to
being? Why is existence the natural result of thinking? What’s one got to do with the other?
And yet Descartes thinks that this is a killer argument, and in fact he repeats it again
because it is so successful in his mind in his much better known Meditations of First
Philosophy, published in 1641. So how can an argument that seems so bad have started a
whole new direction in philosophy?
And here is a case that exemplifies Reasons D and E above of why arguments can be hard
to follow and identify: this is a very specific argument made on the assumption that the
reader is well aware of the Scholastic debate around existence and essence. Those
arguments flourished in the Middle Ages, and Descartes here is linking rational thought to
existence. We exist as thinking things. Thinking is our essence. This is actually a Big Deal
in philosophy, the distinguishing mark that separates Medieval from Modern philosophy.
We are still, almost 400 years later, still Cartesian (and ‘Cartesian’ is simply the way we call
someone or something that follows from Descartes). If you believe that we have a rational
soul, and that this rational soul distinguishes us from all other things, then you’re still a
Cartesian.
So what assumptions belie Descartes’ argument? Here’s one: existence is clearly not just
physical existence; there is spiritual (actually “of the soul”) existence as well. Is this a
warranted assumption? Do we, in other words, have good reason to assume the truth of
this? And in the history of philosophy, the answer is that it kind of depends. What do we
mean by ‘existence?’ What is IS? Are we talking about essences? Don’t we get in trouble
when we talk of a multi-substance universe? Generally speaking, in the western
philosophical tradition, we freely make this assumption; in the eastern philosophical
tradition we do not. So as you see, this gets complicated.
Here’s another assumption: thinking is the defining action of a human being. Now is that a
warranted assumption? And again, we split philosophical hairs here. What constitutes
‘thinking?’ Is the “I think” premise encompassing of everything else, or is it purely about
thinking? So again, this gets complicated real quickly.
You want my take on it? I don’t think Descartes is right. There’s more to our existence than
just thinking, and those ways of existing are by no means ‘lower’ than our ability to think.
Existence is complicated—it can’t be boiled down to an essential quality. It is much larger
than what Descartes believes.
Does that make sense? I am hoping so because what I’ve just given is of course an
argument. It’s my opinion, and I’ve justified it using evidence that, when taken together,
leads one to infer that Descartes is indeed wrong.
P1: there’s more toe xisting than just thinking
P2; those ways of being are not “lower” than thiinking
P3; existence cant be boiled down to an essential quality
P4: There is more to existence that what Descartes believes
//C Descartes is wrong
3. You want something even more contemporary and more real-life? I am going to honor the
life of Ms. Renee Macklin Good by remembering her in these examples. Ms. Good was of
course the 37-year-old woman who was shot and killed by ICE agent Jonathan Ross in
Minneapolis, Minnesota on January 7th. Here are some letters regarding this opinion piece
written by the mayor of Minneapolis on January 8th:
To the Editor:
The recent killing of Renee Good, a 37-year-old woman, by a federal officer in Minnesota
demands careful legal scrutiny, not political slogans or emotional reactions.
Under well-established constitutional principles and longstanding federal case law, the
use of deadly force by a government agent is justified only when there exists an
immediate, objective and unavoidable threat to the life of the officer or others. That
determination must rest on observable facts at the precise moment of force is used, not
on subjective fear or speculative danger.
In cases where an officer stands only a few feet from a vehicle that is stationary or just
beginning to move, basic physics, human reaction time and standard police training all
indicate that reasonable avenues of evasion are typically available.
Federal courts have repeatedly held that an officer may not voluntarily place himself in
the path of a vehicle and then rely on that self-created risk to justify lethal force. The
threat must be truly imminent and not reasonably avoidable by other means.
This is not an ideological issue; it is a legal one.
Whether the constitutional limits on the use of deadly force were respected or violated
public trust depends on those limits being applied rigorously, transparently and without
exception.
When the state exercises its ultimate power, the burden of justification must be equally
exacting.
Juan Carden
St. Louis
On to the assessment!
A. First off, is this an argument? Can you spot Mr. Carden’s opinion? And as it
turns out, we can. His opinion is that the case of Ms. Good’s killing needs to be
thought through legally, not ideologically or emotionally. In fact, it is so
important to him that he repeats it twice, in ¶1 and again in ¶5. What evidence
does he have to justify this? The fact that using “well-established constitutional
principles and longstanding case law” regarding when federal agents can use
lethal force.
B. Is this a good argument? I would have to say no. Why not? We can discuss in
class, but to get things started, ask yourself this: how does a legal issue get one
to justice being done for Ms. Good? Is that not resting on the assumption that
this Justice Department, under this President, actually follows legal ruling and
precedent? On the other hand, he may be appealing to centrists who don’t like the emotional appeals that cloud the issue. He’s trying to give a logically cmpelling case, sot it may be a good argument.
Here’s another:
To the Editor:
At some point, we have to ask ourselves as Americans whether we are willing to accept a
country with no shared moral base line, no principle that rises above political affiliation.
Are we comfortable living in an America where a 37-year-old mother can be shot dead in
the street and, almost immediately, have powerful figures justify it or attempt to
construct an alternate reality that contradicts what we all plainly witnessed?
Are we comfortable living in an America where an insurrection that threatened our
democracy is minimized; where foreign and domestic policymakers increasingly act as
judge; jury and executioner; and where blatant misinformation is delivered from behind
the White House logo?
These are not abstract concerns. They cut to the heart of whether we still agree on right
and wrong, truth and falsehood, restraint and accountability.
We should be asking ourselves where the line is, and at what point we decide we simply
will not tolerate the disregard for the democratic norms and human dignity that
generations before us worked to preserve.
Red, purple or blue, the question is not about ideology. It’s about whether we can still
come together to defend something as fundamental as basic decency.
Seth Schlussel
San Francisco
How should we begin assessing this claim?
A. Again, is this an argument? Can you spot Mr. Schlussel’s opinion?
B. And this one’s difficult. Look at ¶s 1-3. ¶2 and 3 end in question marks. What do we do
about them? Again, we can do this in class. try and turn the interrogative into declarative
We cannot be comfortable living in an America where a 37-year-old mother can be shot dead in the street and, almost immediately, have powerful figures justify it or attempt to
construct an alternate reality that contradicts what we all plainly witnessed?
The conclusion is, “It’s about whether we can still come together to defend something as fundamental as basic decency. “although we can make it stronger: “We must come together to define something as fundamental as basic decency”
Come up with an argument of your own: Is MR. Schlussel argument any good?
I think that is does have some good in it however it can use more facts instead of the theoretical questions to have stronger premise. It is a clear appeal to emotion and because it appeals to american values, especially as more people are becoming more disillusioned with the execution of our laws, this is thus a better argument than Mr. Cardens argument above.
To the Editor:
Re “Early Comments Cast Doubts Over ICE Inquiry” (news analysis, front page,
Jan. 11):
JD Vance’s false claim that ICE agents have “absolute immunity” not only suggests
agents have something to hide; it also reveals an ignorance of federal law.
Civil rights crimes perpetrated by ICE agents and their bosses are addressed specifically
in Federal Statute 242, “Deprivation of Rights Under Color of Law.”
In the Justice Department’s own language: Section 242 makes it a federal crime for a
person “acting under color of any law to willfully deprive a person of a right or privilege
protected by the Constitution or laws of the United States.”
If those acts lead to the death of that person, the statue says, punishment could include
imprisonment or a death sentence. It offers no immunity.
Statute 242 was intended to protect Renee Good’s civil rights, and the F.B.I. has a
responsibility to investigate possible deprivation of those rights. If F.B.I. officials refuse
to investigate, wouldn’t they themselves be violating Statute 242, in depriving Ms. Good
of the right to due process, as well as of one of her legal protections?
Mark Thurmond
Kneeland, Calif.
Now this one is fascinating because of its structure. We will, of course, discuss. But what makes it
fascinating is the very last sentence. It marks it as being of a very different type of argument than
the first two Letters to the Editor, and indeed, of any other example in this exercise.
Week 3
Writing Assignment is introduced
jdd002 conclusions: measures make no sense
What is his argument
p1 it takes time to drive to the station and find parking and catch the train
p2 They will not have a car when they arrive at the end of their train ride
p3 jdd0002 will have to wait for another train to get elsewhere
p4 Mass transit is used by hibbos and druggies
C// Measure M makes no sense
C. asses it for any assumptions. Are they warranted?
you have to drive to the train station. Warranted Is there good reason for this assumption? Not really—there are other options to get to train station
Hobos and druggies are prime users of mass transit in La. Warranted in that a lot of homeless people do use mass transit and there is drug use in the cars.
There’s no such thing as rideshare — Unwarranted
D. Now your turn:
Is this a good argument? Give a good argument that supports your conclusion:
P1 Argument is easily countered
P2 The only premise that is warranted is the “hobos and druggies” part but even that is hyperbolically stated
//: argument is not good
What is the gender of jdd0002? Give me your argument for your conclusions
p1 the user name is suspicious. A lot of men use similar handles for SPAM accounts
P2 nothing stated about the safety of mass transit. Women would stress the safety elements
P3 does not show a balanced awareness of the situation
P4 no foresight shown
//: jdd0002 is male
Types of arguments
There are in 2 types of arguments:
Deductive arguments are arguments that may have 100% truth attached to them. They are assessed according to their logical form. These are arguments that are true by definition. They have a high degree of certainty attached to the,. They can be logically compelling. They are also the type of argument least used.
Inductive arguments are arguments that, at best, are probably true. They do not have 100% certainty and they are arguments from experience and past occurrence. These are the most common types of arguments given.
A deductive argument that is 100% certain is called a sound argument. An inductive argument that has a high degree of probability is a cogent argument
W 1/28/2026
P1
P2 Inferential process
.
Px
//C
In deduction the inferential process leads to 100% truth/ certainty assuming that:
a) the premises are true;
b) the logical from is correct. The logical forms must follow a certain set number of Rules of Inference (back of the book)
c) If the premises are true and the proper logical form followed, it is impossible for the conclusion to be false. We can get to 100% certainty. We may be 100% certainty it is not guaranteed.
D) Notice the conditions in c): if those conditions are met, and this of course is why it is important to check those assumptions
e) Deductions are based on the Principle of Noncontradiction. Something cannot be X and not X at the same time
F) Deductions go from the more universal case to the more particular case
g) they are true by definition, i.e. they need a definition to be true
h) mathematical process
i) it lives in the world circumscribed by its own premises. It cant tell us anything new about the world
j) it analyzes claims and premises to draw forth a conclusion. It gives Analytic truth
In induction, it is the exact opposite.
a) inductions can never be 100% true/certain
b) There is only probabilistic truth
c) It is thus based on mathematical probability
d) They argue from particulars to universals
e) True by experience
f) inductions go beyond the premises: they tell us something new about the world and can lead to meaningful conclusions that expand our understanding of various phenomena.
g) There is an iterative process to coming up with better and better inductions. SOmetimes called Abduction, but also known as Inference to the Best Explanation (IBE).
h) Tells us something new about the world.
i) the Scientific method
j) IT gives us Synthetic knowledge
EXAMPLE: Using David Hume’s Case. How do we know that the sum will rise tomorrow?
INDUCTION Everyday we wake up and it ’s morning, the sun has risen. So tomorrow is just another day; when we get up in the morning the sun will rise. In fact, every morning, the sun rises, and so it will do so tomorrow as well. This is an argument from past experiences. It is inductive. It does not give 100% certitude. It is a mathematical probability that it will happen only.
Here we are synthesizing particular experiences of our life here on earth to make a more universal claim about sunrises and morning time. How can we get to an argument whereby we can be 100% sure that the sun will rise tomorrow?
DEDUCTION How can we get to an argument whereby we can be 100% sure that the sun will rise tomorrow? The earth is an oblate spheroid that rotates about its axis. Mornings in a specific part of the earth is defined as the time where the sun lights begins to lights up that area on earth. We are all on this planet earth and so will experience sun rises every morning, so the sun will rise again tomorrow.
This argument analyzes what must be true if we hold these definitions to be true. From those universal definition we can infer more particular claims about out life here on earth, especially in morning times.
SO— in general, we can refer to good arguments accordingly:
A good inductive argument has a high degree of probability of being true. The premises are true, and when this happens, we get a strong inductive claim. When the assumptions behind the premises are warranted, we call such arguments Cogent. Bad inductive arguments that have little to no warrant and/or lead to not very probable truth we call weak or uncogent.
A good deductive argument has 2 parts
A deductive argument must have true premises.
But a good deductive argument must also have a proper logical form.
An argument that has true premises but bad logical form is called Invalid.
An argument with false premises but has true logical form is called Valid. A valid argument may still be wrong!
When both the premises are true and the proper logical form is followed, this gives us a Sound argument. These are 100%
If those acts lead to the death of that person, that statue says, punishment could include imprisonment or a death sentence. It offers no immunity
In this case, “those acts led to the death of Renee Good” is my x and Punishment could include impriionment or a death penalty is my Y
P1: x—>y
P2 X
//Y