Glossary

A reasoning process that like induction does not offer certainty but has the subtle distinction from induction by proposing best explanations rather than a probable claims.

With respect to confirmation of hypotheses, the extent to which the hypothesis fits or aligns with data or facts it is attempting to explain.

A characteristic of imprecise words or statements that are open to more than one distinct meaning.

A thing that is similar to something else, for the purpose of making a claim about the "something else" based on shared properties with the analogue(s).

The component to the left of the horseshoe (⊃) in a conditional sentence.

A set of propositions, one of which, the conclusion, is supported by the others, the premises.

As a type of compound sentence, an 'if and only if' sentence symbolized by a 'triple bar' (≡) separating the component sentences.

A proposition that makes a claim about the relationship between two classes.

A deductive argument consisting of three categorical propositions (two premises and a conclusion); collectively, these three propositions feature exactly three classes; each of the three classes occurs in exactly two of the propositions. A categorpical syllogism must be in standard form. See glossary entry for 'standard form.'

A synonym for "class" - the basic logical unit of Aristotelian logic. See "class."

A set of things. Classes are the fundamental "logical unit" for Aristotelian logic. "Category" is a synonym for "class."

The name of a class in Aristotelian logic, often referred to simply as "term."

A characteristic of a proposition that denotes that the proposition conveys information.

With respect to confirmation of hypotheses, the extent to which the hypothesis is logically and internally coherent.

For a given class of things (for example S), another class which contains all things that are not members of the original class. By convention the class complement is denoted by a tilde in in front to the original class designation (for example, ~S).

A sentence that contains at least one other sentence as a component part.

The proposition in an argument that is the claim being backed up with reasons (premises).

With respect to confirmation of hypotheses, the extent to which the hypothesis aligns with other hypotheses that are confirmed or accepted.

As type of compound sentence, an 'if-then' sentence symbolized with a 'horseshoe' (⊃) between 'if' sentence (i.e., the antecedent) and the 'then' sentence (i.e., the consequent.)  In other contexts, referred to as a 'hypothetical' or an 'implication.'

As a type of compound sentence, an 'and' sentence that joins two conjunct sentences with the 'dot' (•) symbol.

The component to the right of the horseshoe (⊃) in a conditional sentence.

The relationship between two propositions whereby they have opposite truth values; when one is true, the other must be false, and vice versa.

A relationship between two proposition types (A and E) whereby both cannot be true, but both could be false.

An operation on a categorical proposition that involves changing the order of the subject and predicate terms (i.e., switching them.)

A version of the verb "to be" that connects the subject term to the predicate term in a standard-form categorical proposition.

The technique for demonstrating invalidity of an argument whereby one must constructs a new argument with the same form as the original, whose premises are in fact true and whose conclusion is in fact false.

An argument that guarantees, that is, necessitates, its conclusion.

In a definition, the word being defined.

In a definition, the word being defined.

A characteristic of a statement (or set of statements) that denotes that the statements describe how things actually are. ( No value claims are made - contrast with "prescriptive." )

As a type of compound sentence, an 'or' sentence that joins two disjunct sentences with the 'wedge' (∨) symbol.

A characteristic of a proposition that denotes that the proposition invokes feelings.

A class of things that has no members.

An argumentative passage that leaves certain propositions unstated. These unstated propositions are "tacit."

The relationship between two classes that maintains that the classes have no members in common.

A property that a proposition has when its truth implies the existence of something.

Writing down a list of declarative sentences that express the propositions in an ordinary-language argument, and clearly marking which of these sentences expresses the conclusion.

Informal fallacies that involve arguing in such a way that the issue that's supposed to be under discussion is somehow sidestepped, avoided, or ignored.

Informal fallacies that occur in arguments that make an unwarranted presumption of truth, either explicitly or implicitly

Informal fallacies that involve manipulation of linguistic forms to emphasize facts, claims, emotions, etc. that favor one's position, and to de-emphasize those that do not.

Informal fallacies that involve making weak claims that do not make their conclusions very probable.

Failure of the testing of a hypothesis or theory to demonstrate expected/implied result, resulting in rejection or rework of the hypothesis.

With respect to confirmation of hypotheses, the extent to which the hypothesis leads to further new and useful knowledge.

With respect to a categorical syllogism, the feature determined by the arrangement of the middle term in the two premises. There are four possible arrangements, and 'figure' is expressed as a single numeric, 1-4.

A defect that occurs in arguments that are bad because they have bad (invalid!) form.

A tentative theory that requires further information to confirm it or deny it.

The process involving hypothetical reasoning to formulate of a testable hypothesis to explain something.

A technique for solving problems or constructing explanations, whereby a hypothesis is put forth and its implications defined, using if-then Iogic.

In logic, something that is presumed incorrectly, mistakenly.

Communicating contents over and above the literal meaning of what we actually say. (This one of several forms of the fallacy of equivocation.)

Words or phrases that may signal the presence of a premise or of a conclusion.

An argument that supports a claim that follows with probability, not certainty. (No guarantees as with deductive arguments.)

Refers to the process of basing a conclusion on evidence, or reasoning —as in the verb to infer. It may also refer to the conclusion/claim itself.  An argument itself consisting of a single premise and conclusion is sometimes called an inference.

In the context of the Square of Opposition, given a known truth value for one proposition type, inferring the truth value of the other proposition types.

A defect in arguments that are bad because of their content, their context, and/or their mode of delivery.

The property of a deductive argument that is not valid.

The study of the human activity of reasoning. A particular "logic" is a set of rules and techniques for distinguishing between good reasoning and bad reasoning.

With respect to a categorical syllogism, refers to the combination of two features of the argument, its 'mood' and its 'figure' and is expressed as mmm-f  where mmm refers to the mood (letter names of proposition types) and f refers to the figure number, 1-4. See 'mood' and 'figure'.

A sentential representation of an argument, whereby the the capital letters for the simple sentences are converted to lower-case variables. The validity (or lack thereof) can thereby be verified for any specific argument that has that form.

The symbolized operation with the widest scope in a compound sentence.

The premise of a categorical proposition that contains the major term (i.e., the predicate of the conclusion.)

The term that appears in the predicate position of the conclusion of a categorical syllogism.

The term that appears in each of the premises, but not in the conclusion, a categorical syllogism.

The premise of a categorical proposition that contains the minor term (i.e., the subject of the conclusion.)

The term that appears in the subject position of the conclusion of a categorical syllogism.

With respect to a categorical syllogism, the feature determined by the types of categorical propositions contained and the order in which they occur, expressed as three letters denoting the proposition types.

A cause that is a necessary condition.

A required condition, represented by the consequent of a conditional statement. For example, given P⊃Q, Q is a necessary condition.

As a type of compound sentence, a 'not' sentence that implies that it is not the case that the main sentence, with 'not' removed, is true, and is symbolized with a 'tilde' (~) as a prefix.

An operation on a categorical proposition that involves (1) changing the quality (from affirmative to negative or vice versa) and (2) replacing the predicate with its complement. (See "complement,")

Express the meaning of something written or spoken using different words.

The relationship between two classes that maintains that one class is partially contained within the other; the two classes have at least one member in common.

The "I" type of categorical proposition that affirms that the subject class is partially included in the predicate class. Some S are P.

The "O" type of categorical proposition that affirms that there is at least one member of the subject class that is in the predicate class. Some S are not P.

A past case deemed to be the same as as a new case for the purposes of guiding its treatment legally.

The noun (or noun with modifiers) that picks out the class represented by the grammatical predicate of the categorical sentence/proposition.

A proposition that provides reason or evidence to support an argument's conclusion.

A characteristic of a statement (or set of statements) that denotes that the value claims are made - that something is good or bad. Prescriptive statements describe how things ought or ought not to be. (Contrast with "descriptive." )

A statement, in the form of a declarative sentence, used as a premise or conclusion in an argument.

The attribute of a categorical proposition that describes whether it is "affirmative" (denoting inclusion) or "negative" (denoting exclusion.)

The word at the beginning of a categorical proposition that indicates the quantity expressed by the proposition.

The attribute of a categorical proposition that denotes whether it is "universal" (referring to all members of a class) or "particular" (referring to some -- at least one -- class members.)

Showing an argument is bad by offering a new, obviously bad argument that has analogous form to the original.

An account of the meanings of a language's well-formed constructions that establish the conditions for expressing truth versa falsehood.

A sentence that does not contain any other sentence as a component part.

The attribute of a deductive argument that is valid and has premises that are true.

Listing the premises of a categorical syllogism in the correct order, with the major premise first, the minor premise second.

The property of an inductive argument that brings higher probability for its claim.

The relationship between A and I propositions and between E and O propositions whereby the truth of the universal one of the pair entails the true of its particular counterpart (its subaltern.) If A is true, then corresponding I is true. If E is true, then corresponding O is true.

The relationship between two proposition types, I and O, whereby they both cannot be false, and either or both could be true.

The noun (or noun with modifiers) that picks out the class represented by the grammatical subject of the categorical sentence/proposition.

A cause that is a sufficient condition.

A condition, represented by the antecedent of a conditional statement, that is enough on its own to support the consequent. For example, given P⊃Q, P is a sufficient condition.

The rules governing what counts as a well-formed construction within that language; i.e., the language's grammar.

Understood or implied without being stated. In this course, a premise or conclusion in an ordinary-language argument may be tacit (not stated explicitly.)

The "A" type of categorical proposition that affirms that the subject class is entirely contained with the predicate class. All S are P.

The "E" type of categorical proposition that affirms that the no members of the subject class are contained in the predicate class. The two classes have no members in common. No S are P.

A characteristic of imprecise words or phrases that have a range of meanings, leaving the writer's/speaker's intent uncertain.

The attribute of a deductive arguments that guarantees its conclusion. That is, IF its premises are true, its conclusion must be true also. That is, it is impossible for the premises to be true and conclusion to be false.

The property of an inductive argument that makes its claim relatively improbable.

The relationship between two classes that maintains that one class is entirely contained within the other.