Chapter 1 Flashcards
Argument:
A group of statements of which one is claimed to follow from the others.
Statement:
A sentence that is either true or false.
Premise:
the information intended to provide support for a conclusion.
Logic:
Logic is the systematic use of methods and principles to analyze, evaluate, and construct arguments.
Truth-values:
the values of ‘true’ and ‘false’ that applies to a statement.
Proposition:
the information content imparted by a statement or, simply put, its meaning.
Inference:
the term used by logicians to refer to the reasoning process that is expressed by an argument.
Logic
the systematic use of methods and principles to analyze, evaluate, and construct argument
Argument
- A group of statements in which the conclusion is claimed to follow from the premise(s)
- Arguments can have more than one premise but only one conclusion
Statement
A sentence that is either true or false
Truth value
Every statement has a truth value (either true or false)
Proposition
The information content or meaning of a statement.
Conclusion indicators:
words and phrases that indicate the statement is a conclusion.
Premise indicators:
words and phrases that indicate the statement is a premise.
Inferential claim:
a passage that expresses a reasoning process (from premises to a conclusion).
Conclusion Indicators
Therefore
Consequently
It proves that
Thus
In conclusion
Suggests that
So
It follows that
Implies that
Hence
We can infer that
We can conclude that
Premise Indicators
Because
Assuming that
As indicated by
Since
As shown by
The fact that
Given that
For the reason(s) that
It follows from
Explanation:
Provides reasons for why or how an event occurred. By themselves, explanations are not arguments; however, they can form part of an argument.
Truth value analysis:
A truth value analysis determines if the information in the premises is accurate, correct, or true.
Logical analysis:
a logical analysis determines the strength with which the premises support the conclusion.
Deductive argument:
An argument in which the inferential claim is that the conclusion follows necessarily from the premises.
-In other words, under the assumption that the premises are true it is impossible for the conclusion to be false.
Inductive argument:
An argument in which the inferential claim is that the conclusion is probably true if the premises are true.
- In other words, under the assumption that the premises are true it is improbably for the conclusion to be false.
- In other words, the probable truth of the conclusion follows from the premises
Inferential claim in a deductive argument
- Conclusion follows necessarily from premises
- It is impossible for conclusion to be false assuming premises are true
Inferential claim in an inductive argument
- Conclusion probably true if premises are true
- It is improbable that conclusion is false assuming premises are true
Identifying Deductive and Inductive Arguments: Key words/phrases
- Deductive: necessarily, certainty, definitely
- Inductive: probably, likely, unlikely, plausible
Strength of argument
- Deductive: conclusion necessarily true
- Inductive: conclusion probably true
Types of arguments
- Deductive: mathematics, geometry, definitions
- Inductive: analogical, legal, moral, statistical, scientific (see Part IV)
Valid deductive argument:
An argument in which, assuming the premises are true, it is impossible for the conclusion to be false.
Invalid deductive argument:
an argument in which, assuming the premises are true, it is possible for the conclusion to be false.
Sound deductive argument:
a deductive argument that is valid and its premises are true.
Unsound deductive argument:
an invalid deductive argument or a valid deductive argument with a false premise.
Counterexample:
-a counterexample to a statement is evidence that shows the statement is false.
- a counterexample to an argument shows the possibility that premises assumed to be true do not make the conclusion necessarily true.
Truth analysis
Concerns statements
A statement is either true or false
Is required for soundness and strength.
Logical analysis
Concerns arguments
The relationship between premise(s) and conclusion provides the inferential strength of an argument
- Is required for soundness and validity as well as strength and cogency
Counterexample to a statement
Provides evidence that a statement is false
Counterexample to an argument
Shows that true premises do not make the conclusion necessarily true (argument is invalid)
Strong Inductive Argument:
An argument such that if the premises are assumed to be true, then the conclusion is probably true.
Weak inductive argument:
An argument such that either
(a) if the premises are assumed to be true, then the conclusion is probably not true, or
(b) a probably true conclusion does not follow from the premises.
Cogent Inductive Argument:
An argument that is strong and the premises are true.
Uncogent Inductive Argument:
An argument that is either weak or one if its premises is false.
