Reasoning

Logic and Fallacies

1,803 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

Which of the following is a common type of deontic fallacy?

  1. Affirming the consequent

  2. Denying the antecedent

  3. Appeal to ignorance

  4. Fallacy of composition
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Appeal to ignorance is a common type of deontic fallacy that occurs when someone assumes that a proposition is true simply because it has not been proven false, or vice versa.

Multiple choice

Which of the following is a common type of deontic conflict?

  1. Normative conflict

  2. Factual conflict

  3. Logical conflict

  4. Temporal conflict
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Normative conflict is a type of deontic conflict that occurs when two or more norms (such as obligations, permissions, or prohibitions) are in conflict with each other, making it impossible to fulfill all of them at the same time.

Multiple choice

What is the method that Socrates used to arrive at definitions?

  1. Dialectic

  2. Deductive reasoning

  3. Inductive reasoning

  4. Analogy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Socrates used dialectic, a method of inquiry that involves a series of questions and answers, to examine and clarify concepts and arrive at their definitions.

Multiple choice

Which of the following is a valid inference in epistemic logic?

  1. If I know that P, then I know that I know that P.

  2. If I believe that P, then I know that P.

  3. If I know that P, then I believe that P.

  4. If I believe that P, then I know that I believe that P.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is a valid inference because knowledge is a transitive relation. If I know that P, then I know that I know that P, because knowing that P entails knowing that I know that P.

Multiple choice

Which of the following is a valid inference in rational choice theory?

  1. If I prefer A to B, and B to C, then I prefer A to C.

  2. If I prefer A to B, and B is indifferent to C, then I prefer A to C.

  3. If I prefer A to B, and C is indifferent to B, then I prefer A to C.

  4. If I prefer A to B, and B is preferred to C, then I prefer A to C.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is a valid inference because preferences are transitive. If I prefer A to B, and B to C, then I must also prefer A to C.

Multiple choice

What are some examples of a priori knowledge?

  1. The laws of logic

  2. The fact that 2 + 2 = 4

  3. The fact that the Earth is round

  4. The fact that the sun is a star
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

A priori knowledge is knowledge that is known to be true without the need for experience. Examples of a priori knowledge include the laws of logic and the fact that 2 + 2 = 4.

Multiple choice

What is the difference between necessary and contingent truths?

  1. Necessary truths are true in all possible worlds

  2. Contingent truths are true in all possible worlds

  3. Necessary truths are true by definition

  4. Contingent truths are true by definition
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

Necessary truths are statements that are true in all possible worlds. Contingent truths are statements that are not true in all possible worlds.

Multiple choice

What are some examples of necessary truths?

  1. The laws of logic

  2. The fact that 2 + 2 = 4

  3. The fact that the Earth is round

  4. The fact that there is life on other planets
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

Necessary truths are statements that are true in all possible worlds. Examples of necessary truths include the laws of logic and the fact that 2 + 2 = 4.

Multiple choice

What are some examples of contingent truths?

  1. The fact that the Earth is round

  2. The fact that there is life on other planets

  3. The fact that humans are mortal

  4. The fact that the sun is a star
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

Contingent truths are statements that are not true in all possible worlds. Examples of contingent truths include the fact that the Earth is round, the fact that there is life on other planets, and the fact that humans are mortal.

Multiple choice

What are some examples of a priori necessities?

  1. The laws of logic

  2. The fact that 2 + 2 = 4

  3. The fact that the Earth is round

  4. The fact that there is life on other planets
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

A priori necessities are necessary truths that are known to be true without the need for experience. Examples of a priori necessities include the laws of logic and the fact that 2 + 2 = 4.

Multiple choice

In deontic logic, the symbol 'O' is commonly used to represent which deontic modality?

  1. Obligation

  2. Permission

  3. Prohibition
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The symbol 'O' is typically used to represent obligation in deontic logic.

Multiple choice

Which deontic modality is often expressed using the phrase 'it is permissible to'?

  1. Obligation

  2. Permission

  3. Prohibition
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Permission is often expressed using the phrase 'it is permissible to' in natural language.

Multiple choice

In deontic logic, the symbol 'F' is commonly used to represent which deontic modality?

  1. Obligation

  2. Permission

  3. Prohibition
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The symbol 'F' is typically used to represent prohibition in deontic logic.

Multiple choice

In deontic logic, the relationship between obligation and permission is often represented using the following formula: $O(p) ≡ ¬F(¬p)$. What does this formula express?

  1. Obligation implies permission

  2. Permission implies obligation

  3. Obligation is equivalent to the negation of prohibition

  4. Prohibition is equivalent to the negation of obligation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The formula $O(p) ≡ ¬F(¬p)$ expresses the equivalence between obligation and the negation of prohibition.

Multiple choice

In deontic logic, the relationship between permission and prohibition is often represented using the following formula: $P(p) ≡ ¬O(¬p)$. What does this formula express?

  1. Permission implies obligation

  2. Obligation implies permission

  3. Permission is equivalent to the negation of obligation

  4. Prohibition is equivalent to the negation of permission
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The formula $P(p) ≡ ¬O(¬p)$ expresses the equivalence between permission and the negation of obligation.