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

Which of the following is a paradox that arises from the idea that truth is a property of actions?

  1. The liar's paradox

  2. The sorites paradox

  3. The Münchhausen trilemma

  4. The Euthyphro dilemma
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Euthyphro dilemma is a paradox that arises from the idea that truth is a property of actions. The paradox is that if an action is good because it is commanded by God, then it is not good in itself. However, if an action is good in itself, then it does not need to be commanded by God.

Multiple choice

Which of the following is a problem that arises from the idea that truth is a property of statements?

  1. The problem of induction

  2. The problem of universals

  3. The problem of evil

  4. The problem of free will
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The problem of induction is a problem that arises from the idea that truth is a property of statements. The problem is that we can never be certain that a statement is true, even if it has been supported by a large amount of evidence.

Multiple choice

Which of the following is a possible solution to the problem of induction?

  1. The principle of uniformity of nature

  2. The principle of causality

  3. The principle of sufficient reason

  4. The principle of non-contradiction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The principle of uniformity of nature is a possible solution to the problem of induction. The principle states that the future will resemble the past in terms of its regularities.

Multiple choice

What is the most common type of epistemic logic?

  1. S5

  2. S4

  3. KD45

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

S5 is the most common type of epistemic logic because it is the strongest and most expressive. It includes all of the axioms of S4 and adds the axiom of positive introspection, which states that an agent knows that they know something if they know it.

Multiple choice

Which of the following is a central concept in deontic logic?

  1. Validity

  2. Obligation

  3. Syllogism

  4. Quantifier
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Obligation is a fundamental concept in deontic logic, referring to the normative force that requires an action or state of affairs to be brought about.

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.