Critical Thinking Flashcards
What is Critical thinking?
Employs argument rather than rhetoric
What is an argument?
A set of statements linked in a particular way ,it will have one or more premises and one conclusion which is the end point
What are the premises intended to do?
Provide support for the conclusion
What is the aim of an argument?
To establish the truth of a statment
What is validity?
If the premises were true the conclusion would have to be true
it would be impossible for all the premises to be true and the conclusion false
Could there be a valid argument with false premises and a true conclusion ?
Yes
Socrates is an Elephant
All elephants are Greek
Socrates is Greek
Could there be a valid argument with true premises and a false conclusion?
No
In no possible circumstances could the premises be true and the conclusion false
A useful method for showing that an argument is invalid
The method of counter example
How can we be sure that the conclusion of an argument is really true?
Is the argument valid?
Are its premises actually true?
only when answer yes in both occasions do we have grounds to accept the conclusion
When is an argument sound?
A valid argument with true premises
An argument is said to be deductively valid iff…
It is logically impossible for the premises to be true and the conclusion false.
An argument is inductively strong iff…
the truth of the premises makes the truth of the conclusion probable but does not guarantee it
To say that an argument is inductively sound is to say..
It is inductively strong and its premises are actually true
Why is deductive logic monotonic?
the more premises you add the more conclusions you may draw
Why is inductive logic non monotonic?
sometimes a conclusion is made less probable by new info
What is an antecedent?
The sentence which forms the if part
What is the consequent?
The sentence which forms the then part
What is a sufficient condition?
The truth of the first statement would guarantee the truth of the second statement.The truth of the first one is all you need ,sufficient enough to ensure the truth
E.G
Having your head cut off is a sufficient condition for being dead.There are many other ways to die ,but decapitation is sufficient enough to ensure it.
What is a necessary condition?
The truth of the first statement is required or necessary for the truth of the second.
E.G
Paying your tuition fees is a necessary condition for graduating.If you are to graduate you must pay your fees but you also need to do a few other things as well like pass exams
What is the layout of a Modus Ponens argument
A- B
A
C= B
What is the layout of Fallacy of affirming the consequent
A- B
A
C =A
What is the layout of the Fallacy of denying the antecedent
A -B
NOT A
C=NOT B
What is the layout of Modus Tollens
A-B
NOT B
C=NOT A
How can we demonstrate the fallacies
Using the counter example technique
A set of statements are consistent iff…
There is a logically possible situation where they are all true at once
Two statements are said to be logically equivalent iff..
The bio conditional formed from them is logically necessary
Each may be validly deducted from one another
There is no logically possible situation in which only one of them is true.
Your name is morris moss is it not?
It is not!
What is an argumentum ad hominem?
An argument directed against the person rather than the views they are expressing
What is a Tu quoque fallacy?
You Too
Like an argumentum ad hominem the focus is on the person rather than the views they are expressing but with a particular emphasis on hypocrisy
What is the deriving ought from is fallacy
based on David Hume’s observations that if X is the case doesnt mean that it ought to be the case
Eg
arguments from human nature
What is the weak analogy fallacy?
arises from an argument appealing to relevant similarites between two things.
the dissimilarites outweigh the similarites
What is the false dilemma?
Assuming that there are only 2 options (often extremes) when there may be others
What is the straw man fallacy?
The arguer ignores the opponents real position and misrepresents the persons argument in order to make it easier to attack.
What is the post hoc ergo propter hoc causal fallacy?
Infer X cause Y merely on the basis that X preceded Y
eg the rooster crows before sunrise therfore the rooster causes the sun to rise
What is the inversion of Cause and Effect causal fallacy?
Mistakenly infer that if X causes Y,an absence of X will prevent Y
The base rate fallacy?
the proportion of one group that has a certain feature is higher than the proportion of another group that has that feature. Therefore, some X that has that feature is more likely to be from the first group than the second.
Eg
Rex is either a rat or a cat, 75 % of cats are black but only 45 % of rats are black. Rex is black. So Rex is probably a cat
What is the fallacy of equivocation?
When an argument trades on ambiguity
Name the fallacy
Of course slavery shouldn’t be abolished. We’ve had slavery here for centuries.
Deriving ought from is
Name the fallacy
Lecturers say their job is becoming harder and harder and that they deserve better pay and conditions. But the government should ignore them; they’re just a bunch of whingeing liberals.
Ad homneim
What is the correspondence theory of truth?
A proposition is true iff it corresponds to the facts
What is the coherence theory of truth?
A statement is true iff it coheres with some belief system
