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 an example of a necessary truth?

  1. The sun is a star.

  2. The sky is blue.

  3. I am thinking.

  4. 2 + 2 = 4.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The statement '2 + 2 = 4' is an example of a necessary truth because it is a statement that is true in all possible worlds.

Multiple choice

Which of the following is an example of a physical possibility?

  1. The existence of God.

  2. The existence of unicorns.

  3. The existence of a talking cat.

  4. The existence of a round square.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A physical possibility is something that is not self-contradictory and is consistent with the laws of physics. The existence of a talking cat is a physical possibility, even though it is not a very likely possibility.

Multiple choice

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

  1. The existence of God.

  2. The existence of unicorns.

  3. The existence of a talking cat.

  4. The existence of a round square.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A logical possibility is something that is not self-contradictory. The existence of a round square is a logical possibility, even though it is not a physical possibility or a metaphysical possibility.

Multiple choice

What is the Non-Contradiction Principle?

  1. The principle that states that a statement cannot be both true and false at the same time.

  2. The principle that states that a statement cannot be both true and false at the same time and in the same respect.

  3. The principle that states that a statement cannot be both true and false at the same time and in the same respect, regardless of the circumstances.

  4. The principle that states that a statement cannot be both true and false at the same time and in the same respect, regardless of the circumstances or the context.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Non-Contradiction Principle is a fundamental principle of logic that states that a statement cannot be both true and false at the same time and in the same respect. This means that a statement cannot be both true and false at the same time, regardless of the circumstances or the context.

Multiple choice

What is the significance of the Non-Contradiction Principle?

  1. It is a fundamental principle of logic that ensures that our reasoning is consistent and coherent.

  2. It is a fundamental principle of logic that ensures that our reasoning is consistent and coherent, and that our conclusions are valid.

  3. It is a fundamental principle of logic that ensures that our reasoning is consistent and coherent, and that our conclusions are valid and reliable.

  4. It is a fundamental principle of logic that ensures that our reasoning is consistent and coherent, and that our conclusions are valid, reliable, and useful.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Non-Contradiction Principle is a fundamental principle of logic that ensures that our reasoning is consistent and coherent, and that our conclusions are valid. This means that if our premises are true, then our conclusion must also be true.

Multiple choice

Which of the following is an example of a Rule Consequentialist argument?

  1. Lying is always wrong, even if it would save a life.

  2. It is sometimes permissible to lie if it would save a life.

  3. Stealing is always wrong, even if it would prevent someone from starving.

  4. It is sometimes permissible to steal if it would prevent someone from starving.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This argument exemplifies Rule Consequentialism, as it asserts that lying is always wrong, regardless of the consequences in a particular situation. It focuses on the consequences of following a general rule against lying.

Multiple choice

In modal logic, what is a possible world?

  1. A world that is consistent with the laws of logic

  2. A world that is consistent with the laws of physics

  3. A world that is consistent with the laws of nature

  4. A world that is consistent with the laws of morality
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In modal logic, a possible world is a world that is consistent with the laws of logic. It is a world in which the laws of logic hold true, and in which the facts of the world are different from the facts of the actual world.

Multiple choice

Which of the following is an example of a modal adverb?

  1. Possibly

  2. Necessarily

  3. Probably

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

A modal adverb is an adverb that expresses a modal concept, such as possibility, necessity, probability, or certainty. The word "possibly" is an example of a modal adverb because it expresses the modal concept of possibility.

Multiple choice

Which of the following is an example of a deontic modal?

  1. Obligatory

  2. Permissible

  3. Possible

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

A deontic modal is a modal that expresses a deontic concept, such as obligation, permission, or prohibition. The word "obligatory" is an example of a deontic modal because it expresses the deontic concept of obligation.

Multiple choice

Which of the following is an example of an epistemic modal?

  1. Knowingly

  2. Believingly

  3. Possibly

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

An epistemic modal is a modal that expresses an epistemic concept, such as knowledge, belief, or doubt. The word "knowingly" is an example of an epistemic modal because it expresses the epistemic concept of knowledge.

Multiple choice

Which of the following is an example of a temporal modal?

  1. Eventually

  2. Always

  3. Possibly

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

A temporal modal is a modal that expresses a temporal concept, such as time or tense. The word "eventually" is an example of a temporal modal because it expresses the temporal concept of time.

Multiple choice

Which of the following is an example of a dynamic modal?

  1. Causally

  2. Intentionally

  3. Possibly

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

A dynamic modal is a modal that expresses a dynamic concept, such as action or change. The word "causally" is an example of a dynamic modal because it expresses the dynamic concept of causation.

Multiple choice

Which of the following is an example of a belief modal?

  1. Believably

  2. Disbelievably

  3. Possibly

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

A belief modal is a modal that expresses a belief concept, such as belief or disbelief. The word "believably" is an example of a belief modal because it expresses the belief concept of belief.

Multiple choice

Which of the following is NOT a central concept in Deontic Logic?

  1. Obligation

  2. Permission

  3. Prohibition

  4. Validity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Validity is a concept primarily associated with deductive logic, not Deontic Logic. Deontic Logic focuses on normative concepts such as obligation, permission, and prohibition.

Multiple choice

Which of the following is a valid Deontic inference rule?

  1. From 'It is obligatory to do X' infer 'It is permissible to do X'

  2. From 'It is permissible to do X' infer 'It is obligatory to do X'

  3. From 'It is prohibited to do X' infer 'It is permissible to do X'

  4. From 'It is permissible to do X' infer 'It is prohibited to do X'
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

From 'It is obligatory to do X' we can infer 'It is permissible to do X', as something that is obligatory is also permissible.