ETECH 171- Final Review #2
What are some common patterns of deductive reasoning?
1. Hypothetical syllogism 2. Categorical syllogism 3. Argument by elimination 4. Argument based on mathematics 5. Argument from definition
What types of statements are these examples: 1. Red is a color. 2. Abortion is morally wrong. 3. The Matrix is a better movie than Titanic.
1. physical statement 2. moral statement 3. evaluative statement
What are the two key questions one should ask when evaluating an argument?
Are the premises true? Do the premises provide good reasons to accept the conclusion?
If we're in Paris, then we are in France. If we're in France, then we are in Europe. So, if we are in Paris, then we are in Europe.
Chain arguments (valid) If A then B. If B then C. Therefore, if A then C.
If A then B. A. Therefore, B.
modus ponens
Define explanans.
the explanation (the cause) ["explanandum" because "explanans"
Define conclusion.
the statement that premises support/prove
Examples of conclusion indicators?
therefore, hence, so, it follows that, wherefore, thus, consequently
Define deductive argument.
these arguments try to prove their conclusions with rigorous, inescapable logic ex. All humans are mortal. Socrates is human. Therefore, Socrates is mortal.
Define inductive arguments.
these arguments try to show their conclusions are PLAUSIBLE (likely or probable), given their premises: ex. So far, every class, the professor has worn a tie. Therefore, next class, the professor will wear a tie.
Define hypothetical syllogism.
three line argument that contains at least one conditional ex. If we're in Sacramento, then we're in California. We're not in California. Therefore, we're not in Sacramento.
What is the past-event test?
used to distinguish between an argument and an explanation if it points at a past event, it is probably an explanation *usually people don't argue "X occurred"
What is the common knowledge test?
used to distinguish between an argument and an explanation if it points at something that is common knowledge, it is probably an explanation
Define antecedent.
usually, the part that directly follow "if" in a conditional sentence
Define explanandum.
what is explained (the event) ["Explanandum because "Explanans"]
If we're in Los Angeles, then we're in the US. We are in the United States. So, we are in Los Angles.
Affirming the consequent (invalid) If A then B. B. Therefore, A.
Are reports arguments?
no; reports are statement made to convey information ex. "More people moved to the south this year." "Oil prices dropped today, thus so did gas prices." (still a report in spite of the use of a conclusion indicator)
Are commands, questions, or exclamations ever statements?
no; rhetorical questions are the exception as well as ought imperatives
What are some indicator inductive words?
probably, likely, one would expect, odds are, reasonable to assume
Define statistical argument.
rests on statistical evidence *b/c statistical evidence is generally used for probable rather than certain claims they are usually inductive
Define rhetorical question.
a sentence that has the grammatical form of a question but is meant to be understood a statement ex. Don't you know smoking will kill you? (means: Smoking will kill you.)
What is a statement?
a sentence/utterance that can be viewed as either true or false
Define categorical syllogism.
a three-lined argument in which each statement begins with the word all, some, or no. ex. All oaks are trees. All trees are plants. So all oaks are plants.
If A then B. B. Therefore, A.
affirming the consequent
If we're on Neptune then we are in the solar system. We are in the solar system. Therefore, we're on Neptune.
affirming the consequent
Define inductive generalization.
an argument in which a generalization is claimed to be probably true based on information about some members of a particular class ex. All dinosaur bones so far discovered have been more than 65 million years old.
Define a valid deductive argument.
an argument in which it is impossible for all premises to be true and the conclusion to be false. If the premise are true, the conclusion must be true. The truth of the premises would guarantee the truth of the conclusion.
Define argument by definition.
an argument in which the conclusion is presented as being true in virtue of the definition of some key word or phrase ex. 1. Bob is a bachelor. Therefore, Bob is unmarried. 2. Janelle is a cardiologist. Therefore, Janelle is a doctor.
Define argument based on mathematics.
argument in which the conclusion depends largely or entirely on some mathematical calculation or measurement ex. Because x=3 and y=5 Therefore, x+y=8
Define causal argument.
asserts or denies that something is the cause of something else
What are some indicator deductive words?
certainly, definitely, this entails that, conclusively
If A then B. If B then C. Therefore, if A then C.
chain arguments
Define argument from authority.
claim is asserted by citing some presumed authority or witness (who has said the claim is true)
If A then B. Not A. Therefore, not B.
denying the antecedent
If I am female then I am a person. I am not female. Therefore I am not a person.
denying the antecedent
Are illustrations considered arguments?
examples of a claim ex. Many wildflowers are edible. For example, daises and day lilies are delicious in salads.
What are some common patterns of inductive reasoning?
1. Inductive generalization 2. Predictive argument 3. Argument from authority 4. Causal argument 5. Statistical argument 6. Argument from analogy
Identify the following: 1. I ski because I think it is fun. 2. You should ski because it is fun.
1. explanation 2. argument
What is not an argument?
Conditional (if-then) sentences: e.g.: If it rains, the picnic will be cancelled. Most common forms: If A then B; B if A.'
How should you go about finding the conclusions without indicators?
Find the MAIN ISSUES; determine the author's position Look at the BEGINNING AND END; it's usually there. See which statement "THEREFORE" fits best in front of The BECAUSE trick: (fill in the blank) The arguer (conclusion) believes_____________ (premise(s)). because___________
Modus ponens?
If A then B. A. Therefore B.
Affirming the consequent?
If A then B. B. Therefore, A.
Chain arguments?
If A then B. If B then C. Therefore, if A then C.
Which patterns are not logically reliable but still deductive?
If A then B. Not A. Therefore not B. (denying the antecedent) AND If A then B. B. Therefore A. (affirming the consequent)
Denying the antecedent?
If A then B. Not A. Therefore, not B.
Modus tollens?
If A then B. Not B. Therefore, Not A.
What is the statement test?
If it makes sense to put "it is true that" or "it is false that" in front of it then it is a statement. If it doesn't make sense then it is not a statement.
If we're in Shanghai, then we are in China. So, we are in China, because we are in Shanghai.
If we're in Shanghai, then we are in China. (If A then B.) We are in Shanghai. (A) So, we are in China. (B)
Define consequent.
Usually the part that follows "then" in a conditional sentence
Define unsupported assumptions.
When someone puts forth what the believe but does not intend for any of their statement to support another ex. People aren't afraid of dying; they are afraid of not living.
Define prediction argument.
a prediction is a statement about what may or will happen in the future ex. Most US presidents have been tall. Therefore, probably the next US president will be tall.
Define ought imperative
a sentence that has the form of a command but is a statement about what ought to be done ex. "Do X!" really means "You should do X."
What is an argument?
group of statements, one or more of which is/are intended to prove or support another statement
If A then B. Not B. Therefore, Not A.
modus tollens
If we're in London, then we're in England. We are not in England. So, we are not in London.
modus tollens (valid) If A then B. Not B. Therefore, Not A.
Do conditionals always have "if" or "then"?
no; e.g., In the event of rain, the picnic will be cancelled.
Are explanations arguments?
no; explanations attempt to show why something is the case (not argue THAT IT IS the case) ex. Titanic sank because it struck an iceberg usually offers up a causal explanation for something that is already accepted as true
Define argument by elimination.
seeks to logically rule out various possibilities until only a single possibility remains ex. Either Joe walked to the library or he drove. But Joe didn't drive to the library. Therefore, Joe walked to the library.
What are some examples of premise indicators?
since, for, seeing that, in as much as, in view of the fact that, because, as given that
Define premise.
statements in an argument offered as evidence or reasons why one should accept another statement