UNIT 1: Introduction to Critical Thinking
What is the difference between rational and irrational belief?
Rational belief is supported by your evidence, and irrational belief is not supported by your evidence.
What are three three steps of argument analysis and what is the goal of each one?
1. Identifying Arguments: decide the type(s) of writing that are present
2. Reconstructing Arguments: make the argument more clear by putting into standard form
3. Evaluating Arguments: figure out the argument's rational strength (if it is true, if there are good reasons/evidence to believe)
True or False: Premises can be explicit or implicit, but conclusions can only be explicit? And what general versus specific implicit premises?
False.
Implicit means that the premise or conclusion isn't directly stated in the argument at all, but rather implied for the audience to piece together. Explicit means that the premise or conclusion is directly stated (as is the case with most of the arguments we've seen in this course).
Why should we care about critical thinking? (Hint: There's lots! Name as many as you can)
Reasons to care about critical thinking: to get at the truth, gain knowledge, believe things rationally and responsibly (not just because its easy or convenient), examine morality, fairly evaluate both sides of controversial issues, be clear thinkers, believing the effects of our actions, and ultimately, to determine the kind of person we become!
Also: to state arguments and positions more clearly, see both sides of a debate, improve our discourse and writing, speak and write more clearly, and be a better debater!
What are the three different types of sentences? And, what is the difference between a sentence and a proposition?
interrogative (question), imperative (command), declarative (statement or denial)
A sentence is a string of words, while a proposition is the specific thought or idea that a sentence expresses.
True or False? Every proposition has exactly one truth value. And, what do I do if I don't know if something is true?
True.
Sentences are either true or false. Simply because it is difficult to know whether they are true or false, or we disagree about them, does not mean the correspondence theory is false. We don't always have perfect access to the truth. We don’t know everything, evidence can be difficult to assess, it could beyond our knowledge at this point but it still has a truth value.
What are the logical words that we use in critical thinking?
Conjunction - and: A and B is true (if both A is true and B is true)
Disjunction - or: A or B is true (if either A is true or B is true) <-- they both don't have to be true, but at least one of them must be true
Negation - not: not A is true (if A is false)
Conditional - if, then: If A, then B (if A is true, B must be true) <-- every time there's an A, the B follows
Biconditional - if and only if: A if and only if B (if A then B, but also: if B, then A) <-- A and B stand or fall together. Biconditionals is often closely connected to giving a definition of something. Ex: someone is a bachelor if and only if they are an unmarried male
What are the three types of writing? What are examples of each?
1. Descriptive writing: describes a person, object, or event. Example: Some news articles
2. Rhetorical writing: asserts the author's opinion, but doesn't offer reasons, can be forceful and emotional; may convince people. Example: some politicla speeches
3. Argumentative writing: gives reasons or evidence to establish the truth of a particular claim. Ex. the arguments we've looked at in this course!
Note: a long text or speech might well contain all three kinds of writing (or perhaps more).
Our goal is to zero in on the argument or arguments, and ignore everything else.
Example of the Three Types of Writing (The Bridge)
Descriptive writing: "Work is underway to build a bridge over the river. The bridge will be 50m long and 20m high."
Rhetorical writing: "Clearly, we ought to build a bridge over the river. And we should definitely limit the cars that go on it. And let's fix the park while we are at it."
Argumentative writing: "We ought to build a bridge over the river, because doing that is the best way to solve the traffic problems."
What makes a belief irrrational and what are examples of this in real life?
Your belief is irrational when it is not supported by your evidence.
Motivational errors: beliefs motivated by hopes or fears
Example: "My partner comes home for lunch almost everyday at noon. Today he told me he has a lunch meeting so we won't be home, but I forgot." (Which type of motivational error is this?)
What are the ingredients required for knowledge?
1. Truth (it corresponds to the world)
2. Belief (you personally believe it)
3. Rationality / Justification (you have good evidence)
4. [One more ingredient that epistemologists think we need, but not covered in this course.]
Example: If Sarah knows it is raining:
What are premises and conclusions? What are indicator words for these?
The two types statements in an argument (one type provides reason or support, and the other type provides the main point that tries to convince the audience)
Premise indicators:
Conclusion indicators:
Note: Remember that indicator words are not always present.
What are two ways that an argument can go wrong?
1. A premise is false
2. The conclusion doesn't follow from the premises.
Example argument: Should you wear a mask? (COVID-19)
Let's say: we're in a disagreement, someone else is trying to argue and say "we shouldn't wear a mask". There's two ways they might respond to this argument.
How might someone resist this argument?
What's the difference between the Principle of Charity and the Principle of Faithfulness?
The Principle of Charity:
When reconstructing an argument, try to make the argument as strong as possible.
The Principle of Faithfulness:
When reconstructing an argument, try to make the argument consistent with the author's intentions.
Why shouldn't I say that something is "true for me, but not true for you?" Conversely, what kinds of truths can depend on us?
Truth is about correspondence to the world, not your beliefs. These facts that are based in reality are true for everyone.
According to the the correspondence theory, truth is objective. Truth is correspondence to the world, not to our beliefs (nor our culture's beliefs). When something is true, it's because of the way the world is.
However, there are some truths that do depend on us. For example:
Whether these are true depends on people's tastes, thoughts, and feelings. This is perfectly consistent with the correspondence theory. Since we are part of the world, we determine the truth of certain propositions - those that are about us! But many (maybe most?) truths do not depend on us in this way.
Truths that do depend on us:
"I love ice cream" (could be true depending on my preferences, whether I actually do love ice cream... someone else saying this could have a different truth value)
"Everyone in my family opposes the death penalty" (could be true depends on the opinions on my family, whether whether they actually do or don't... someone else saying this could have a different truth value)
"She is popular" (could be true depending on peoples' beliefs and opinions of whoever the "she" is)
What are the two kinds of validity we learned about? Which one are we focusing on in this course?
1. Semantic validity: Valid because it follows a valid argument form
2. Modal validity: Valid because of the meaning of the terms
In SSH105, we're mostly interested in semantic validity, where the arguments actually follow a valid argument form. But, that doesn't mean some arguments aren't also modally valid (valid because of what the terms mean or don't mean)
Example:
Is this argument valid?
Final answer: There are actually two kinds of validity, and that is the reason for the discrepancy.
What are the three belief attitudes that someone can have towards a proposition? How many can you have at once? When do we look for more evidence and when do we not? What is an example of this?
Believe, disbelieve, and withhold belief (you can only have do one of these things at once)
If we have enough evidence to determine one way or the other, then we believe or disbelieve. If we don't have enough evidence, then we should withhold belief until we can look for more and decide.
When it comes to believing a proposition, we have three options:
What's the difference between a valid and an invalid argument? Does valid mean the same thing in philosophy as it does in everyday life? Why or why not?
Defining Valid and Invalid
An argument is valid if:
It's impossible for the premises to be true and the conclusion to be false
OR
The truth of the premises guarantees the truth of the conclusion
***Remember: this has nothing to do with whether the premises are actually true! (It's just about the relationship between the premises and the conclusion)
[Pretend the premises are true, and then check: is the conclusion true if the premises are true?]
An argument is invalid if:
It is not valid
OR
It is possible for the premises to be true and the conclusion false
OR
the premises do *not* guarantee the truth of the conclusion
Also note: This is a special use of the word valid - not what we mean when we say "that's a valid point"
^That's not the philosophical / critical thinking use of the term "valid".
A statement isn't valid / a point isn't valid - an argument is valid or an argument is invalid (ex. an argument form)
So it's a set of statements, or some statements support other statements. That's going to be valid or invalid.
What is standard form and why is it useful? What step of argument analysis do we use standard form for?
We'll be using Standard Form to reconstruct arguments (Step 2).
Since everything is numbered and labelled, we can easily refer to the premises and conclusion.
Also, standard form helps us rule out which propositions are irrelevant to the logic of the argument at hand (such as examples, jokes, appeals to emotion, stories, comments about people who disagree, etc.). Additionally, it makes the author's assumptions clear (we can figure out which premises they have and haven't argued for).
Examples of standard form:
Another example:
One more example:
These arguments are all written in standard form where the premises give us to reason or support their conclusions.
Note that:
There can be any number of premises. (See that the flower example has only one premise)
You could have an argument with 20 or 30 premises (the more premises you have, the more difficult it will be to analyze the argument because it will be hard to wrap your mind around them all) but you could in theory have lots and lots of premises.
The order of the premises doesn't matter, but some orders might make it easier to understand the argument than others.
Why do we say that validity is like "playing pretend?" What's cheap validity?
Validity like "Playing Pretend"
By playing pretend and forget the constraints of real life, we are able to learn about validity because we aren't worried about or focused on whether the argument's premises are true or false.
It's about the relationship between the conclusion and the premises. Meaning that if the premises *were* true, would the conclusion automatically have to be true as welll? Does the conclusion follow logically from the premises?
Example A:
1. This flower is pretty.
2. (Therefore,) this flower is orange.
[Valid or Invalid? Why or why not?]
Example B:
1. All pretty flowers are orange.
2. This flower is pretty.
3. (Therefore), this flower is orange.
[Valid or Invalid? Why or why not?]
*Remember: it doesn't matter if these premises are true or false in real life ("playing pretend").
Cheap Validity
Reconstructing an argument to make it valid along the lines of the Principles of Charity. We do so by adding a premise to make the argument valid (*even though that premise is false in real life!*)
"It will rain tomorrow. My magic 8 ball said so."
This argument is invalid. However, we can reconstruct in a way that makes it valid:
However, premise 2 is clearly false.
You can make any invalid argument valid, by just adding, as a premise "If the premises are true, then the conclusion is true."
Often, this additional premise will be false. Then, you've simply moved the problem to another place.
When doing argument reconstruction, it's normally a good idea to make the argument valid.
What are the three tips for determining validity or invalidity?
Tip 1: Find examples to establish invalidity ("counterexamples").
Tip 2: Look for arguments that follow the same pattern, where validity and invalidity might be easier to identify.
Tip 3: Check the pattern (argument forms).
1) If P, then Q. 2) Q. 3) Therefore, P. <-- They are affirming the consequent.
What are the six ways that people deal with arguments? According to this course, which one should we aim to be in everyday life?
The credulous person (believes everything they hear (is gullible)
The person of contradictions believes the opposite of everything they hear (is a contrarian)
The dogmatist person holds onto their own opinions no matter what (stubborn)
The skeptic doesn't believe anything, thinks evidence needs to be perfect in order to believe anything which almost never happens (a void of belief)
The relativist somehow thinks that everyone is right in their own way, and self-defeating because because we can't be right about everything (people-pleaser)
And finally, the one we should aim to be in everday life; the rational thinker examines arguments with an open mind, changes their mind when the evidence demands it, is willing to give up comfortable or popular beliefs when the argument calls for it, will also go along with popular views when the arguments call for it, and will form beliefs on good evidence even if the evidence isn't perfect (thoughtful)
What are the six valid argument forms and the two invalid argument forms we learned about in class? What's an example of each?
6 valid argument forms:
Argument by Elimination
Example: Argument by Elimination
Equivalence
Example: Equivalence
Hypothetical Syllogism
Example: Hypothetical Syllogism
Modus Ponens (affirming the antecedent)
Example: Modus Ponens (affirming the antecedent)
Modus Tollens (denying the consequent)
Example: Modus Tollens (denying the consequent)
Simplification:
Example: Simplification
2 invalid argument forms
Affirming the Consequent
Example: Affirming the Consequent
Denying the Antecedent
And, this argument is also not valid, so the truth of the premises doesn't guarantee the truth of the conclusion.
Example: Denying the Antecedent
What are the seven tips for argument analysis? What's an example of each?
1) Don't Criticize an Argument by Denying its Conclusion
Example:
Bob:
1) There's a first cause.
2) If there's a first cause, God exists.
3) Therefore, God exists.
John: (3) is false! God doesn't exist. If God did exist, why is there so much evil in the world?
2) Don't Accept an Argument Simply Because You Believe the Conclusion
Example:
Even if (3) is true, that gives you no reason to accept this argument. It is valid, but both premises are false.
3) Direct Criticisms at Individual Premises
Example:
1. Our actions are either caused or random.
2) If our actions are either caused or random, then we don't have free will.
3) Therefore, we don't have free will.
You might think there's something wrong with this argument, but it's not clear which premise to deny. (Free will is a hard problem!) But if you're wanting to resist this argument, you need to direct your criticism at either premise 1 or premise 2.
4) Make Your Criticisms of Premises Substantial
Example:
Unsubstantial Criticisms:
Substantial Criticisms:
5) Don't Distinguish Between Facts and Opinions
Example:
This is a bad and unhelpful distinction. Both of the above statements are either true or false; one is just more controversial and difficult to evaluate.
A better distinction is between:
6) Don't Accept Competing Arguments
Example:
Competing arguments: Argument 1 concludes p, and argument 2 concludes not-p. Example:
1. If there's a first cause, then God exists.
2. There's a first cause.
3. Therefore, God exists.
versus
1. If there's pointless evil, then God does not exist.
2. There's pointless evil.
3. Therefore, God does not exist.
These arguments have opposing conclusions. If you accepted both arguments at the same time, you would accept a contradiction. Although both are valid, both cannot be known (or sound). Thus, you should not accept both simultaneously.
7) Don't Object to Intermediate Conclusions of Compound Arguments
Example:
A compound argument links arguments together to build on each other. For example:
1) The forecast predicts rain tomorrow (premise).
2) If the forecast predicts rain tomorrow, it will rain tomorrow (premise).
3) Therefore, it will rain tomorrow (conclusion 1).
4) If it will rain tomorrow, then it won't be fun to go to the beach tomorrow (premise).
5) Therefore, it won't be fun to go to the beach tomorrow (conclusion 2).
6) If it won't be fun to go to the beach tomorrow, then we shouldn't go to the beach tomorrow (premise).
7) Therefore, we shouldn't go to the beach tomorrow (ultimate conclusion).
This compound argument contains three arguments, linked together.
To object to this argument, you should challenge one of the premises (1, 2, 4, or 6). Since each argument is valid, the conclusions are supported by the premises (true because the premises are true).
Thus, to challenge this argument, do not object to the intermediate conclusions (3, 5); object to the premises supporting 3 or 5.
What is the difference between rationality and truth, and how do they work together? What are some examples of each combination?
Rational belief is person-relative: it depends on your evidence (that you have at a certain time).
Truth is NOT person-relative:
It depends on the way the world is.
Fallibilism: Rational belief (evidence) ≠ true belief (corresponds to the world)
Rationality and truth can actually come apart!
Rational and true: 1+1=2 (corresponds with the world and we have good evidence to support that)
NOT rational but true: Lucky guess, if a magic 8 ball says it's going to rain tomorrow and it does, if you guess a fair coin will land on heads and it does (corresponds with the world but no rational evidence)
Rational but NOT true: good but misleading evidence, if in March Madness football, the last ranked team wins it all, it had never happened before so your belief was rational, but ended up being false (1st time ever)
NOT rational and NOT true: wishful thinking, if you really want your team to win, but there's no good evidence for it, and then the team loses
What are the three kinds of good arguments? Are these types of arguments valid or invalid? How does this connect to the Lottery Paradox?
• Sound: has true premises; objectively good. They do not always give us reason to believe their conclusions (if they're just true by luck) and the premises don't have evidence.
• Strong: has premises that are rational to believe; subjectively good. It must be reasonable to believe all the premises together, not just each premise individually (The Lottery Paradox)* and can have false premises.
• Known: valid with premises that are known to be true; objectively and subjectively good. These arguments have premises that are both true and rational to believe (as good as you can get without 100% proof, which is too high a bar to set)
All of these kinds of good arguments are valid, meaning that if the premises are true, then the conclusion has to be true.
The Lottery Paradox means that for an argument to be strong, it should be reasonable to believe all the premises together, not merely each individually.