# Exercises and Quizzes

##### These exercises are supplemental material on the book *Introduction to Logic*. They are broken down by unit and chapter from the book.

#### Table of Contents

## Fundamental Concepts of Logic

#### Which Type of Sentence?

Choose whether a sentence is Declarative, Exclamatory, Imperative, or Interrogative

#### Arguments and Non-arguments

In each case, does the passage present an argument? Or does it not contain an argument?

#### Deductive or Inductive

Is the indicator word deductive or inductive?

#### Deduction and Induction

For each argument, state whether it is deductive or inductive. Some contain deduction or induction indicator words; others do not.

#### Valid and Invalid

For each of the following deductive arguments, determine whether it is valid or invalid.

#### Enthymemes

An *enthymeme* is an argument that is missing a premise, a conclusion, or both. For each of the following enthymemes, choose the addition that turns the argument into a valid deductive argument.

#### Strong and Weak

For each of the following inductive arguments, state whether it is strong or weak.

#### Soundness and Cogency

For each of the following arguments, determine three things: (a) whether it is deductive or inductive, (b) whether it is valid or invalid (if deductive), or strong or weak (if inductive), and (c) whether it is deductively sound or unsound (if deductive), or cogent or uncogent (if inductive).

#### Consistency and Inconsistency

Consider the following pairs of statements and determine which pairs are consistent and

which are inconsistent

#### Implication

Consider the following pairs of statements. In each case, determine whether the first member of the pair implies the second member.

#### Equivalence

Consider the following pairs of statements. In each case, are the sentences logically equivalent?

#### Necessary and Contingent Statements

Consider the following statements. In each case, is the statement necessarily true, necessarily false, contingently true, or contingently false?

## Categorical Logic

#### Truth Value of Categorical Statements

What is the truth value of the following statements? (I.e., are they true or false?)

#### Characteristics of Categorical Statements

For each of the categorical statements below, determine its label (or kind, i.e., A, E, I, or O), quantity, and quality.

#### Square of Opposition Relations

Select from the options the change from the original statement that uses the relation and assumes the truth value indicated, and then then check the box that indicates whether the new statement is true (T), false (F), or undetermined (U).

#### Testing Immediate Inferences for Validity with the Square of Opposition

Consider each of the immediate inferences below. State which square of opposition relation is used, and whether the inference is valid or invalid.

#### Conversion, Obversion, and Contraposition

Choose the option that will change the original statement using the relation and assuming the truth value indicated, and then choose a second option that indicates whether the new statement is true (T), false (F), or undetermined (U). You will choose two items for each question.

#### More Testing of Inferences

For each of the immediate inferences, determine which of the eight categorical relations is used, and whether the inference is valid or invalid.

#### Standard Form

Abbreviate each of th categorical syllogisms in standard form (i.e., with the major premise listed first, and the conclusion last); then (using the single capital letters from your abbreviation) state the argument’s major term, minor term, and middle term.