Reasoning

Logic and Fallacies

1,716 Questions

Understand the fundamentals of propositional logic, logical inference rules, and paradoxes. This set includes identifying logical fallacies, including those found in classical Nyaya logic. Strong grasp of these concepts is crucial for scoring well in the reasoning sections of competitive tests.

Propositional logic modelsLogical inference rulesTypes of logical fallaciesParadoxes and contingent truthsNyaya logic concepts

Logic and Fallacies Questions

Multiple choice

Foucault argues that power is:

  1. Negative.

  2. Positive.

  3. Both negative and positive.

  4. Neither negative nor positive.
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

Foucault argues that power is both negative, in the sense that it can be used to restrict or control individuals and groups, and positive, in the sense that it can be used to produce new forms of knowledge and subjectivity.

Multiple choice

Foucault argues that power is:

  1. Negative.

  2. Positive.

  3. Both negative and positive.

  4. Neither negative nor positive.
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

Foucault argues that power is both negative, in the sense that it can be used to restrict or control individuals and groups, and positive, in the sense that it can be used to produce new forms of knowledge and subjectivity.

Multiple choice

What is the contrapositive of the proposition "If it rains, then the grass gets wet"?

  1. If the grass gets wet, then it rains.

  2. If it does not rain, then the grass does not get wet.

  3. If the grass does not get wet, then it does not rain.

  4. If it rains, then the grass does not get wet.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The contrapositive of a proposition is a new proposition that is formed by negating the antecedent and the consequent of the original proposition. In this case, the contrapositive of the proposition "If it rains, then the grass gets wet" is "If the grass does not get wet, then it does not rain".

Multiple choice

What is the distribution of the predicate term in the proposition "Some birds can fly"?

  1. Universal

  2. Particular

  3. Singular

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The distribution of the predicate term in a categorical proposition indicates whether the proposition is making a claim about all or some members of the category of things that the predicate term refers to. In this case, the proposition "Some birds can fly" is making a claim about some birds, so the distribution of the predicate term is particular.

Multiple choice

Which of the following is an example of moral relativity?

  1. The fact that some languages have a word for 'good' but no word for 'bad'

  2. The fact that some languages have a word for 'bad' but no word for 'good'

  3. The fact that some languages have both a word for 'good' and a word for 'bad'

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The fact that some languages have a word for 'good' but no word for 'bad' is an example of moral relativity.

Multiple choice

According to Devitt, what is the primary condition for a proposition to be true?

  1. The proposition must be consistent with other true propositions.

  2. The proposition must be believed by a majority of people.

  3. The proposition must correspond to an existing fact.

  4. The proposition must be useful in practice.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Devitt argues that truth is a matter of correspondence between propositions and facts. A proposition is true if and only if it corresponds to an existing fact.

Multiple choice

What is the role of quantifiers in predicate logic?

  1. To specify the number of objects or individuals that satisfy a given predicate.

  2. To restrict the domain of discourse to a specific set of objects or individuals.

  3. To introduce logical connectives between propositions.

  4. To serve as predicates that describe properties or relations between objects.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Quantifiers in predicate logic are used to specify the number of objects or individuals that satisfy a given predicate. The two main quantifiers are the universal quantifier (∀) and the existential quantifier (∃).

Multiple choice

What is the principle of universal instantiation in predicate logic?

  1. Any instance of a universally quantified formula is true.

  2. Any instance of an existentially quantified formula is false.

  3. Any closed formula is true.

  4. Any open formula is false.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The principle of universal instantiation states that any instance of a universally quantified formula is true. This means that if a formula is true for all values of a variable, then it is true for any specific value of that variable.

Multiple choice

What is the principle of existential instantiation in predicate logic?

  1. Any instance of a universally quantified formula is true.

  2. Any instance of an existentially quantified formula is false.

  3. Any closed formula is true.

  4. Any open formula is false.
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

The principle of existential instantiation states that any instance of an existentially quantified formula is true. This means that if a formula is true for at least one value of a variable, then it is true for some specific value of that variable.

Multiple choice

What is the completeness theorem for predicate logic?

  1. Any formula that is true in all models is provable in predicate logic.

  2. Any formula that is provable in predicate logic is true in all models.

  3. Any formula that is true in some model is provable in predicate logic.

  4. Any formula that is provable in predicate logic is true in some model.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The completeness theorem for predicate logic states that any formula that is true in all models is provable in predicate logic. This means that if a formula is true in every possible interpretation, then there is a proof of that formula in predicate logic.

Multiple choice

What is the soundness theorem for predicate logic?

  1. Any formula that is true in all models is provable in predicate logic.

  2. Any formula that is provable in predicate logic is true in all models.

  3. Any formula that is true in some model is provable in predicate logic.

  4. Any formula that is provable in predicate logic is true in some model.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The soundness theorem for predicate logic states that any formula that is provable in predicate logic is true in all models. This means that if there is a proof of a formula in predicate logic, then that formula is true in every possible interpretation.

Multiple choice

What is the difference between a disjunctive syllogism and a conjunctive syllogism?

  1. A disjunctive syllogism has two premises and a conclusion, and the premises are disjunctive statements, while a conjunctive syllogism has one premise and a conclusion, and the premise is a conjunctive statement.

  2. A disjunctive syllogism has one premise and a conclusion, and the premise is a disjunctive statement, while a conjunctive syllogism has two premises and a conclusion, and the premises are conjunctive statements.

  3. A disjunctive syllogism has two premises and a conclusion, and the premises are categorical statements, while a conjunctive syllogism has one premise and a conclusion, and the premise is a hypothetical statement.

  4. A disjunctive syllogism has one premise and a conclusion, and the premise is a categorical statement, while a conjunctive syllogism has two premises and a conclusion, and the premises are hypothetical statements.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A disjunctive syllogism is a syllogism that has two premises and a conclusion, and the premises are disjunctive statements. A conjunctive syllogism, on the other hand, is a syllogism that has one premise and a conclusion, and the premise is a conjunctive statement.

Multiple choice

What is the primary focus of predicate logic?

  1. The study of the relationship between subjects and predicates

  2. The study of the structure of arguments

  3. The study of the validity of syllogisms

  4. The study of the logical consequences of statements
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Predicate logic is a branch of logic that deals with the relationship between subjects and predicates in a proposition.

Multiple choice

Which of the following is a fundamental assumption of signal detection theory?

  1. Stimuli are detected perfectly.

  2. Stimuli are detected based on a comparison with a threshold.

  3. Stimuli are detected based on a comparison with a criterion.

  4. Stimuli are detected based on a comparison with a standard.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Signal detection theory assumes that stimuli are detected based on a comparison with a threshold. This threshold is a hypothetical boundary that separates stimuli that are detected from those that are not.

Multiple choice

Which of the following is an example of a logical fallacy?

  1. Ad hominem

  2. Straw man

  3. False dichotomy

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All of the above are examples of logical fallacies.