Lesson 05: Truth and Consequences: Inference at Last!

Question 1

Inference

Answer 1

a set of propositions in which one proposition (the consequent or conclusion) is alleged to ‘follow from’ the others (the antecedent or premises)

Question 2

What is truth a property of?

Answer 2

Truth is a property of propositions.

Question 3

What is validity a property of?

Answer 3

Validity is a property of arguments or inferences.

Question 4

When is an inference valid?

Answer 4

An inference is valid if and only if it is such that if its antecedent (premises)
were to be true, its consequent (conclusion) would have to be true as well.

Question 5

Immediate inference

Answer 5

An inference that passes directly from one proposition to another proposition, the second proposition being a partial or complete reformulation of the first.

Question 6

Two kinds of immediate inference

Answer 6

Oppositional inference and eduction

Question 7

Mediate inference

Answer 7

a conclusion drawn from two propositions (premises) and the conclusion is not identical with either of the premises.

Question 8

Eduction

Answer 8

Eduction addresses the question of the validity of inferences from one proposition directly to another.

Question 9

Three kinds of eduction

Answer 9

Conversion, contraposition and obversion.

Question 10

Conversion

Answer 10

Convert a proposition, simply have its subject and predicate switch places.

Question 11

Contraposition

Answer 11

Switch the subject and predicate of the original proposition, but this time we complement each term.