Presuppositions

Summary

The video explains the concept of presuppositions in communication, where certain assumptions are left unstated but are crucial for understanding. Presuppositions help make communication more efficient but can lead to problems when the assumptions are false. Various examples, such as 'The King of France has red hair' and 'Have you hidden the bear?', demonstrate how presuppositions affect the truth or falsity of statements. Philosophers debate how to handle statements with false presuppositions, and the video suggests making implicit assumptions explicit to align them with logical principles.

Takeaways

• 🔍 Presupposition is an unstated assumption that is treated as true in communication.
• 💡 Definite noun phrases like 'the champagne' presuppose the existence of the referenced object.
• 🤔 Questions with false presuppositions, like 'Have you hidden the bear?', are problematic to answer because they assume something that is not true.
• 👑 The example 'The king of France has red hair' shows how false presuppositions can create ambiguity in assigning truth values.
• 💍 Statements like 'Ellen's husband runs marathons' presuppose the existence of a husband, which may or may not be true.
• 🍰 When someone asks 'Did you remember to bring the cake?', the presupposition is that there was an expectation for cake to be brought.
• 🔒 Aristotle's blackmail example illustrates how false presuppositions trap people into answering questions in misleading ways.
• 🏬 Comparisons like 'Fruu is a fancier store than Walmart' presuppose that Walmart is a store, which is true and allows for a meaningful comparison.
• 🍿 The claim 'Popcorn is crunchier than democracy' carries a false presupposition because democracy cannot have physical properties like crunchiness.
• 🧠 Resolving the issue of presuppositions in logic involves making the implicit assumptions explicit, allowing for clearer truth-value assignments.

Q & A

What is a presupposition in communication?

A presupposition is a claim that is assumed to be true but left unstated, which makes communication more efficient by not requiring every detail to be explicitly stated.

How do definite noun phrases contribute to presuppositions?

Definite noun phrases, like those starting with 'the,' typically presuppose the existence and often the uniqueness of the thing they refer to, such as 'the champagne' implying that champagne exists.

Why can't we answer 'yes' or 'no' to the question 'Have you hidden the bear?' in a normal living room?

We can't answer 'yes' because that would imply there is a hidden bear, and we can't answer 'no' because that would imply there is an unhidden bear. The question presupposes the existence of a bear, which is false.

How does the statement 'The king of France has red hair' illustrate a problem with presuppositions?

The statement presupposes the existence of a king of France, which is false. Since there's no king of France, it's hard to accept the claim as true or false because both possibilities rely on a false presupposition.

What presupposition is implied in the sentence 'Ellen's husband runs marathons'?

The sentence presupposes that Ellen has a husband. If this presupposition is true, then the claim about the husband running marathons can be either true or false.

What happens when a sentence with a false presupposition, like 'Bobby's wife runs marathons,' is evaluated?

Since Bobby may not have a wife, the presupposition that Bobby has a wife is likely false, which makes it difficult to assign a truth value to the sentence.

How do presuppositions stay the same when negating a sentence?

Negating a sentence doesn't change its presuppositions. For example, 'The king of France has red hair' and 'The king of France doesn't have red hair' both presuppose the existence of a king of France.

What is the issue with assigning truth values to sentences that carry false presuppositions?

Philosophers debate whether sentences with false presuppositions, like 'The king of France has red hair,' are both false, have no truth value at all, or cause problems with principles like the law of the excluded middle.

How can we resolve the presupposition problem in logical terms?

To resolve the issue, we can make presuppositions explicit in logical statements. For example, 'The king of France has red hair' can be translated into 'There exists a king of France, and that person has red hair,' which can clearly be evaluated as false.

How does Aristotle's problem of blackmail illustrate the challenge of presuppositions?

The question 'Have you stopped blackmailing the Persians?' presupposes that Aristotle once blackmailed the Persians. Aristotle cannot say 'yes' without admitting to blackmail, nor can he say 'no' without implying ongoing blackmail, leading to a logical trap.