Logic Chapter 2

Front 1

Sound argument

Back 1

an argument in which the premises provide a sufficient reason to believe the conclusion, where the premises are true and justified, the conclusion follows from the premises at least with probability, and the conclusion is not one of the premises

Front 2

Fallacious argument

Back 2

One that is not sound

Front 3

Non sequitur

Back 3

An argument whose conclusion does not follow, even with probability: an invalid argument

Front 4

Nonstarter

Back 4

An argument with a false or unjustified premise

Front 5

Question-begging argument

Back 5

An argument whose conclusion is assumed by one of the premises from which the conclusion is drawn

Front 6

Argument strength

Back 6

The degree to which the premises support the conclusion; the strength of an argument tends to be directly related to the strength and probability of the premises, and inversely related to the strength of the conclusion.

Front 7

Statement strength

Back 7

How much a statement asserts or implies; one statement is stronger than another if the former implies the latter but the latter does not imply the former

Front 8

Modality

Back 8

The property of a statement according to which it asserts that something is necessary, actual, certain, probable, possible, and so on

Front 9

Modality indicators

Back 9

A term or phrase that expresses the modality of a proposition

Front 10

Deductively sound

Back 10

A sound argument whose conclusion follows with necessity from the premises

Front 11

Inductively sound

Back 11

A sound argument whose conclusion follows at least with probability from the premises

Front 12

Valid argument

Back 12

An argument whose conclusion follows from the premises at least with probability. Validity is necessary but not sufficient for soundness.

Front 13

Deductively valid argument

Back 13

An argument whose conclusion follows from the premises with necessity

Front 14

Inductively valid argument

Back 14

An argument whose conclusion follows from the premises with probability but not necessity

Front 15

Invalid argument

Back 15

An argument that is not valid; a non sequitur

Front 16

Formally valid

Back 16

An argument whose logical form is such that all arguments with the same form are deductively valid. Formal validity is sufficient but not necessary for validity.

Front 17

Fallacy of equivocation

Back 17

The fallacy committed when the premises of an ambiguous argument are true only on one interpretation while the conclusion follows and is non-question-begging only on another.

Front 18

Argument from ignorance

Back 18

The fallacy of concluding that something is false from the premise that it has not been shown to be true, or of concluding that something is true from the premise that it has not been shown to be false.

Front 19

Ad hominem argument

Back 19

A fallacious argument in which the premises describe someone's biases, moral failings, or other personal characteristics, and from which the conclusion is drawn that his opinions or arguments about matters unrelated to himself are false or fallacious.

Front 20

Biasing (or prejudicial) influence

Back 20

Factors other than evidence and argument that influence our judgment but are logically irrelevant to the issue under consideration.