Part 1 - Chapter 1 What Logic Studies Flashcards
A sentence that is either true or false.
Statement
A group of statements of which one (the conclusion) is claimed to follow from the others (the premises)
Argument
The information intended to provide support for a conclusion.
Premise
The statement that is claimed to follow from the premises of an argument.
Conclusion
The study of reasoning.
Logic
Every statement is either true or false; these two possibilities are called truth values.
Truth value
The information content imparted by a statement, or, simply put, it’s meaning.
Proposition
A term used by logicians to refer to the reasoning process that is expressed by an argument.
Inference
Words and phrases that indicate the presence of a conclusion (the statement claimed to follow from premises).
Conclusion indicator
Words and phrases that help us recognize arguments by indicating the presence of premises (statements being offered in support of a conclusion).
Premise indicator
If a passage expresses a reasoning process–that the conclusion follows from the premises–then we say that it makes an inferential claim.
Inferential claim
An explanation provides reasons for why or how an event occurred. By themselves, explanations are not arguments; however, they can form part of an argument.
Explanation
An argument in which it is claimed that the conclusion follows necessarily from the premises. In other words, it is claimed that under the assumption that the premises are true it is impossible for the conclusion to be false.
Deductive argument
An argument in which it is claimed that the premises make the conclusion probable. In other words, it is claimed that under the assumption that the premises are true it is improbable for the conclusion to be false.
Inductive argument
An argument in which, assuming the premises as true, it is impossible for the conclusion to be false. In other words, the conclusion follows necessarily from the premises.
Valid deductive argument
When logical analysis shows that a deductive argument is valid, and when truth value analysis of the premises shows they are all true, the argument is sound.
Sound argument
An argument in which, assuming the premises are true, it is possible for the conclusion to be false. In other words, the conclusion does not follow necessarily from the premises.
Invalid deductive argument
If a deductive argument is invalid, or if at least one of the premises are false (truth value analysis), then the argument is unsound.
Unsound argument
An argument such that if the premises are assumed to be true, then the conclusion is probably true. In other words, if the premises are assumed to be true, then it is improbable that the conclusion is false.
Strong inductive argument
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. A single counterexample to a deductive argument is enough to show that the argument is invalid.
Counterexample
An argument such that if the premises are assumed to be true, then the conclusion is not probably true.
Weak inductive argument
An inductive argument is cogent when the argument is strong and the premises are true.
Cogent argument
An inductive argument is uncogent if either or both of the following conditions hold: the argument is weak, or the argument has at least one false premise.
Uncogent argument
