Chapter 5 Flashcards
Class:
A group of objects.
Categorical proposition:
Relates two classes of objects.
Subject term:
The term that comes first in a standard-form categorical proposition.
Predicate term:
The term that comes second in a standard-form categorical proposition.
A-proposition:
Asserts that the entire subject class is included in the predicate class (“All S are P”). – this is a universal affirmative.
I-proposition:
Asserts that part of the subject class is included in the predicate class (“Some S are P”). – this is a particular affirmative.
E-proposition:
Asserts that the entire subject class is excluded from the predicate class (“No S are P”). – this is a universal negative.
O-proposition
Asserts that part of the subject class is excluded from the predicate class (“Some S are not P”). – this is a particular negative
Standard-from categorical proposition.
A proposition that has one of the following forms: “All S are P,” “Some S are P,” No S are P,” “Some S are not P.”
Categorical proposition:
A categorical proposition relates two classes of objects.
Universal Affirmative
All S are P.
An A-proposition affirming that every member of the subject class is a member of the predicate class.
Particular Affirmative
Some S are P.
An I-proposition affirming that at least one member of the subject class is a member of the predicate class.
Particular Negative
Some S are not P.
An O-proposition affirming that at least one member of the subject class is not a member of the predicate class.
Quantity:
‘universal’ and ‘particular’
Quality:
‘affirmative’ and ‘negative’
Quantifiers:
‘all’, ‘no’, and some’ – establish class inclusion and exclusion.
Copula:
‘are’ and ‘are not’ – links subject class to predicate class.
Distributed:
If a categorical proposition asserts something about every member of a class, then the term designating that class is said to be distributed.
Undistributed:
If a proposition does not assert something about every member of a class, then the term designating that class is said to be undistributed.
I- propositions: Some students are sophomores.
Both subject and predicate are undistributed; the proposition does not make an assertion about every student or every sophomore.
O-propositions: Some cars are not fuel-efficient vehicles.
Subject “cars” is undistributed; the proposition does not make an assertion about every car.
Predicate is distributed, since at least one member of “cars” is excluded from every member of “fuel-efficient vehicles.”
Existential import:
When a proposition presupposes the existence of certain kinds of objects.
Opposition:
Occurs when two standard-form categorical propositions refer to the same subject and predicate classes but differ in quality, quantity, or both.
Contradictories:
Pairs of propositions in which one is the negation of the other. A- and O-propositions are contradictories, as are E- and I-propositions.
Immediate argument:
An argument that has only one premise.
Mediate argument:
An argument that has more than one premise.
Conversion:
An immediate argument created by interchanging the subject and predicate terms of a given categorical proposition.
Complement:
The set of objects that do not belong to a given class.
Obversion:
An immediate argument formed by changing the quality of the given proposition, and then replacing the predicate term with its complement.
Contraposition:
Formed by replacing the subject term of a given proposition with the complement of its predicate term and then replacing the predicate term of the given proposition with the complement of its subject term.
Types of immediate arguments
Conversion
Obversion
Contraposition
Obversion:
Change the quality of the proposition, then replace the predicate term with its complement
Complement:
The set of objects that do not belong to a given class.
Contraries
Pairs of propositions that cannot both be true at the same time, but can both be false at the same time. A- and E-propositions are contraries.
Subcontraries:
Pairs of propositions that cannot both be false at the same time, but can both be true; also, if one is false then the other must be true. I- and O-propositions are subcontraries.
Subalternation:
The relationship between a universal proposition (the superaltern) and its corresponding particular proposition (the subaltern).
Conversion by limitation:
When we first change a universal A-proposition into its corresponding particular I-proposition, and then we use the process of conversion on the I-proposition.
Contraposition by limitation:
When subalternation is used to change the universal E-proposition into its corresponding particular O-proposition. We then apply the regular process of forming a contrapositive to this O-proposition.
