Logic Glosssary Terms Flashcards
That which requires empirical justification.
A posteriori (S-FL)
That which does not depend on empirical evidence.
A priori (S-FL)
When the argument is directly against persons, seeking to defame or discredit them. It is also called genetic fallacy, because it attacks at the genesis of an idea rather than the truth of its content.
Abusive ad hominem (S-FL)
A shift of meaning arising as a consequence of changes in the emphasis given to its words or parts, thus leading to fallacious reasoning.
Accent (S-FL)
An informal fallacy when one applies a generalization to an individual case that it does not properly govern.
Accident (S-FL)
An expression is ambiguous if it has more than one meaning.
Ambiguity (S-FL)
An informal fallacy when one of the statements in an argument has more than one plausible meaning because of the loose or awkward way in which the words in that statement are combined.
Amphiboly (S-FL)
Statement which is true or false by virtue of the meaning of the statement alone.
Analytic statement (S-FL)
When an argument appeals to the fact that a view is universally or commonly held as support to its truth.
Appeal to common practice (S-FL)
When careful reasoning is replaced with devices to create enthusiasm and emotional support for the conclusion advanced.
Appeal to emotion (S-FL)
When careful reasoning is replaced with direct or insinuated threats to force the acceptance of the conclusion.
Appeal to force (S-FL)
A fallacy in which a proposition is argued to be true simply on the basis that it has not been proved false, or false simply because it has not been proved true.
Appeal to ignorance (S-FL)
When an argument appeals to a party having no legitimate claim to authority in the matter at hand.
Appeal to inappropriate authority (S-FL)
When an argument is not based on proper reasons but some unfortunate circumstance.
Appeal to pity (S-FL)
Arguments sharing the form – ‘Most people approve of X, therefore X is true.’
Appeal to populace (S-FL)
The strategy of praising someone in order to convince them to do the thing that you want.
Apple polishing (S-FL)
Structure that comprises a conclusion and some premises.
Argument (S-FL)
The basic unit that expresses a complete thought.
Atomic proposition (S-FL)
When we tend to retain and recall only information readily available to us recently or boosted via media coverage.
Availability bias (S-FL)
¬¬𝑝 ≡ 𝑝
Axiom of double negation (S-FL)
An argument begs the question when the reasoner assumes in the premises the truth of what he or she seeks to establish in the conclusion.
Begging the question (S-FL)
The principle that there are only two possible truth-values for a proposition. Classical logic, including categorical logic, propositional logic, and predicate logic, accepts bivalence.
Bivalence (S-FL)
A syllogism (an argument with exactly two premises and one conclusion) that comprises only categorical propositions.
Categorical syllogism (S-FL)
An argument in which the premises do not only support, but are in turn supported by the conclusion.
Circular argument (S-FL)
When the attack is indirectly against persons, suggesting that they adopt their views chiefly because of their special circumstances or interests.
Circumstantial ad hominem (S-FL)
An argument is cogent it its premises are acceptable, relevant to and sufficient for its conclusion.
Cogent argument (S-FL)
A logical system is complete if every logical implication in that system is provable. In other words, for every truth-functionally valid argument, there is a way in this system to deduce the conclusion of that argument from its premises.
Completeness (of a logical system) (S-FL)
A proposition comprising several atomic propositions.
Complex proposition (S-FL)
The argument assumes some unstated premises such that it misleads the audience into believing something which the responder cannot clarify by giving a simple answer.
Complex question (S-FL)
The fallacy of composition is made when (a) one reasons mistakenly from the attributes of a part to the attributes of the whole, or (b) one reasons mistakenly from the attributes of an individual member of some collection to the attributes of the totality of that collection.
Composition (S-FL)
A system is computable if there is an effective procedure to calculate a solution.
Computable (S-FL)
A function that maps objects to truth-values. For example, the concept of being a horse maps a horse, calls it 𝑥, to truth (because 𝑥 is a horse) but a cow, 𝑦, to falsity (because 𝑦 is not a horse).
Concept (in Frege’s terminology) (S-FL)
A proposition that one wants to uphold.
Conclusion (S-FL)
A strategy in natural deduction for arguments with a conditional conclusion. It proves an argument by first assuming the antecedent of the conclusion, working out its consequent and then discharging the assumption itself.
Conditional Proof (CP) (S-FL)
A conjunction is true only when both components (conjuncts) are true.
Conjunction (S-FL)
An argument involving conjunction. The following are valid forms: 𝑝, 𝑞, therefore 𝑝 & 𝑞 (composition); 𝑝 & 𝑞, therefore 𝑝 (decomposition).
Conjunctive inference (S-FL)
A dilemma that argues from how the horns are related to how the entailments are related. The general form is: 𝑝 V 𝑞, 𝑝 → 𝑟, 𝑞 → 𝑠 / ∴ 𝑟 V 𝑠
Constructive dilemma (S-FL)
A categorical syllogism is valid if and only if the premises contain the conclusion; i.e., the conclusion obtains under the conditions that make the premises true.
Containment (S-FL)
Statements that are true in one world but false in another.
Contingent statements (S-FL)
A statement is always false. Contrast ‘tautology.’
Contradiction (S-FL)
The relation that propositions have exactly opposite truth-values.
Contradictory (S-FL)
A combined operation of obverting a proposition, then converting it, and then obverting it again. The resultant proposition takes the form of having non-P in the subject position and non-S in the predicate position.
Contraposition (S-FL)
The relation that two propositions cannot both be true but can both be false.
Contrary (S-FL)
An operation to form propositions by interchanging the subject and the predicate of an original proposition.
Conversion (S-FL)
An argument in which the truth of the premises completely determines the truth of the conclusion given that it is a valid argument.
Deduction (S-FL)
An item to be found.
Definiendum (S-FL)
That which defines a term.
Definiens (S-FL)
A dilemma that argues backwards from what the entailments are not to what the horns are not. The general form is: 𝑝 → 𝑟, 𝑞 → 𝑠, ¬ 𝑟 V ¬ 𝑠 ∕ ∴ ¬ 𝑝 V ¬ 𝑞.
Destructive dilemma (S-FL)
An argument form that has two horns: 𝑝 and 𝑞, each entailing some results.
Dilemma (S-FL)
A disjunction is false only when both components (disjuncts) are false.
Disjunction (S-FL)
A syllogism involving disjunction. A valid argument form is 𝑝 V 𝑞, ¬ 𝑝, ∴𝑞 . An invalid form is 𝑝 V, 𝑝, ∴ ¬ 𝑞.
Disjunctive syllogism (S-FL)
A term is distributed if every member of the class it refers to is exhausted by the proposition containing it.
Distribution (in categorical logic) (S-FL)
The fallacy of division is formed when (a) one reasons mistakenly from the attributes of a whole to the attributes of one of its parts, and (b) one reasons mistakenly from the attributes of a totality of a collection of entities to the attributes of the individual entities themselves.
Division (S-FL)
A method of proof is effective if every argument can be determined, within a definite number of steps, to be either valid or invalid.
Effective (S-FL)
Expressions that usually arouse particular feelings or judgments.
Emotive words (S-FL)