Philosophy Final
Conjunctive statement
A and B So, A and So, B
Good counterexample
A substitution instance in which the premises are well known truths and the conclusion is a well known falsehood.
1. A substitution instance of an argument form may be valid even if the argument form itself is invalid
False
1. Some arguments are false.
False
Every argument with a valid form is valid
True
Counterexample method
1) Identify the most logically sensitive form of the argument. Use capital letters to stand for statements or terms. 2) Find English statements or terms that, if substituted for the capital letters in the conclusion of the argument form, produces a well known falsehood. 3) Substitute these Englishe statements or terms for the relevant capital letters uniformly throughout the argument form. 4) Find English statements or terms that, if substituted uniformly for the remaining capital letters in the argument form, produce premises that are well known truths. 5) Check your work, if you have succeeded, you have shown the argument to be invalid.
Form 1
A B So, A and B
Statement
A declarative sentence that is either true or false.
Constructive Dillema
A or B If A then C If B then D So, C or D
Disjunctive Syllogism Version 1
A or B Not A So, B
Disjunctive Syllogism Version 2
A or B Not B So, A
Form 2
A or B Not both A and B A So, Not B
Argument Form
A pattern of reasoning
Argument form
A pattern of reasoning
Argument
A set of statements where some of the statements; called the premises, are intended to support another, called the conclusion.
As understood by logicians, an argument is....
A set of statements, one of which is supported by the others
A premise of an argument is...
A statement intended to provide support for another statement
Categorical Statement
A statement that relates two classes or categories, where a class is a set or a collection of things. Often signaled by terms like "all", "some", and "no"
Cogent Argument
A strong argument in which all of its premises are true.
Counter example
A substitution instance in which the premises are true and the conclusion is false.
Sound argument
A valid argument in which all of the premises are true.
A term is...
A word or phrase that stands for a class of things
Term
A word or phrase that stands for a class of things.
Form 6 - Total Encapsulation - Valid
All A are B All B are C So, All A are C
Form 7 - Partial Occlusion - Valid
All A are B Some C are Not B So, Some C are not A
Valid Argument Form
An argument form in which every substitution instance is a valid argument.
Invalid argument form
An argument form that has some invalid substitution instances.
Valid argument form
An argument in which every substitution instance is a valid argument
Valid argument
An argument in which it is necessary that, if the premises are true, then the conclusion is true.
Invalid argument
An argument in which it is not necessary that, if the premises are true, then the conclusion is true.
Weak Argument
An argument in which it is not probable that, if the premises are true, that the conclusion is true.
Strong Argument
An argument in which it is probable (but not necessary) that, if the premises are true, then then conclusion is true.
Deductive argument
An argument in which the premises are intended to guarantee the conclusion.
Inductive argument
An argument in which the premises are intended to make the conclusion probable, without guaranteeing it.
Uncogent Argument
An argument that is either weak, or strong with at lease one false premise.
Unsound argument
An argument that is invalid or has at least one false premise.
Formally valid argument
An argument that is valid in virtue of its form
Formally Valid Argument
An argument that is valid in virtue of its form.
Substitution Instance
An argument that results from uniformly replacing the variables in an argument form with statements (or terms)
Substitution instance
An argument that results from uniformly replacing the variables in an argument form with statements (or terms)
Disjunction
An either-or statement
Appeal to Authority
An expert in the field says that P is true So, Probably P is True
Conditional statement
An if - then statement
Conditional Statement
An if-then statement, often simply called a "conditional"
1. A disjunctive syllogism has the following form:
Either A or B; Not A; So, B.
Form 8 - Partial Encapsulation - Valid
Every A is a B Some A are C So, some B are C
Modus Ponens
If A then B A So, B
Fallacy of affirming the consequent
If A then B B So, A
Hypothetical Syllogism
If A then B If B then C So, If A then C
Fallacy of denying the antecedant
If A then B Not A So, Not B
Modus Tollens
If A then B Not B So, Not A
Identify the form of the Fallacy of Denying the Antecedent
If A, then B. Not A. So, Not B.
What is the form of the fallacy of Denying the Antecedent
If A, then B. Not A. So, Not B.
1. A hypothetical syllogism has the following form:
If A, then B; If B, then C; So, if A, then C
1. The fallacy of denying the antecedent has the following form:
If A, then B; Not A; So, not B.
1. The argument form "If A then B; Not B; So, not A" is called
Modus Tollens
Statistical Syllogism
N% of Fs are Gs X is an F So, X is a G
Enumerative Induction
N% of observed Fs have been Gs So, probably N% of Fs are Gs
Not being able to figure out a counterexample proves
Nothing
1. An invalid argument form in one that has
Some invalid substitution instance
Negation of a statement
The denial of the statement
A good counterexample shows that the argument form is not valid by showing that
The form does not preserve the truth in every instance
Antecedant
The if-clause of a conditional (not including the word "if")
Inductive Logic
The part of logic that is concerned with the study of methods of evaluating arguments for strength and weakness.
Deductive Logic
The part of logic that is concerned with the study of methods of evaluating arguments for validity and invalidity.
Conjuncts
The statements comprising a conjunction
Disjuncts
The statements comprising a disjunction
Logic
The study of methods for evaluating whether the premises of an argument adequately support its conclusion.
Consequent
The then-clause of a conditional (not including the word "then")
1. All invalid arguments can have false premises and a true conclusion.
True
1. In "If Suzie goes to the party, then John will go," the antecedent is "Suzie goes to the party.
True
29. A conditional statement is the same thing as a hypothetical statement
True
A statement is either true or false
True
1. When "or" is taken in the exclusive sense, the statement "We'll go swimming or hiking" says what?
We'll go swimming or hiking, but not both
Argument from Analogy
X and Y share properties F, G, and H X also has property I So, Y probably has property I
An argument form is
a pattern of reasoning
buttercup is a yellow parakeet this is
a statement
pigs can fly this is
a statement
A categorical statement is
a statement that relates two classes or categories
1. Which of the following is a substitution instance of the argument form "All A are B; No B are C; So, no A are C"?
a. All dogs are fish; No dogs are mammals; So, no fish are mammals. b. All dogs are mammals; No fish are mammals; So, no dogs are fish. c. All mammals are dogs; No mammals are fish; So, no fish are dogs. d. All fish are dogs; No dogs are mammals; So, no fish are mammals
Which of the following is an example of a conditional statement?
a. All whales are mammals. b. It's not the case that Sue loves Bill. c. If Pamela loves Joe, then Joe loves Pamela. d. Either Bob or Jim will ask Mary to the dance
1. The fallacy of affirming the consequent has the following form
a. If A, then B; B; So, A.
1. The statement "If Monarchos wins the Belmont Stakes, then Monarchos will be a Triple Crown winner" is a disjunction.
false
9. All valid arguments have true conclusions
false
A good counterexample employs well-known truths for its premises and conclusion.
false
A substitution instance of an argument form may valid even if the argument form itself is invalid
false
All arguments have more than one premise
false
All sentences are statements
false
An argument is any set of statements
false
"go to your room!" this is
not a statement
1. An argument that results from uniformly replacing letters in an argument form with terms or statements is a substitution instance of that form.
true
1. If an argument form is invalid, then so is every substitution instance of that argument form
true
A counterexample proves that an argument form is invalid
true
An argument that results from uniformly replacing letter in an argument form with terms or statements is a substitution of that form
true
An arguments conclusion is affirmed on the basis of its premises.
true
Commands are not statements
true
More than one argument can have the same form
true
More than one argument is the same thing as a hypothetical statement
true
The statements comprising an "either-or" sentence are called disjuncts
true