Which Sentences Are Lying About Exclamation Marks?

  • Thread starter some_one
  • Start date
In summary, the conversation discusses three sentences, A, B, and C, and their truthfulness or falseness. The question asks which claim is correct regarding these sentences. The conversation also touches on the confusion caused by the statement that all sentences ending in an exclamation mark are lying, and how it contradicts itself. The final conclusion is that B is truthful, A contradicts itself, and C is false. The conversation also mentions the limitations of classical logic in assigning truth values to certain propositions.
  • #1
some_one
79
1
data:

A.each sentence which ends with exclamation mark is lying!
B.sentence A is lying!
C.sentence B is lying.

which claim is wright regarding these sentences?
1.A and C are truthful and B is lying
2.C is truthful while A and B are lying
3. B is truthful while A and C are lying
4.C is lying while A and B are truthfulthat exclamation mark thing makes me confused
sentence A contradicts itself
 
Physics news on Phys.org
  • #2
some_one said:
data:

A.each sentence which ends with exclamation mark is lying!
B.sentence A is lying!
C.sentence B is lying.

which claim is wright regarding these sentences?
1.A and C are truthful and B is lying
2.C is truthful while A and B are lying
3. B is truthful while A and C are lying
4.C is lying while A and B are truthful


that exclamation mark thing makes me confused
sentence A contradicts itself

A and B can both be truthful if it is really sentences that end in period that are lying.
 
  • #3
3. B is truthful while A and C are lying

A contradicts itself if assumed to be true. The only way to avoid the contradiction is to assume it is false. Therefore, B is true, and C is false.
 
  • #4
a period meens nothing

how did come to this answer
how did you solve this exclamation mark thing??
 
  • #5
A proposition is either true or false, bot nut both (law of excluded middle + law of non-contradiction). The question clearly suggests that there is a way to assign truth values to the propositions without creating any inconsistency. Proposition A is either true or false. If we assume it is true, we obtain the following:

a. Sentence A is true.
b. Sentence A is a sentence which ends with an exclamation mark.

c. Therefore sentence A is false.

This is inconsistent; we have obtained both the statements "sentence A is true" and "sentence A is false" from the assumption that A is true. Therefore sentence A is not true. Therefore, it must be false. That said, we are forced to accept that B is true, and then that C is false.

To be noted: some propositions are not classifiable as either true or false, this being perhaps the biggest failure of classic Aristotelian logic. For example, the sentence "This sentence is false." leads to a contradiction whether we assume it is true or false. However, like I said, the question suggests that there is a way to assign truth values without contradictions, and so you may assume the laws of classical logic can be applied.
 
  • #6
some_one said:
that exclamation mark thing makes me confused
sentence A contradicts itself

There are 3 possibilities:

1. All sentences that end in an exclamation mark are lying.
2. All sentences that end in an exclamation mark are truthful.
3. Some sentences that end in a "!" are lying, and some are truthful.

The trick here is that many people do not think of or consider possibility #3.
 
  • #7
some_one said:
a period meens nothing

how did come to this answer
how did you solve this exclamation mark thing??

You're right, I meant to say that A was internally consistent with a lie if such was the case, because in saying that exclamation marks are lies - that is a lie. It doesn't mean all exclamation mark sentences are lies however.

B in calling A a lie is merely making a correct observation.

And C of course is a lie because B is True.
 
  • #8
thanks i understand this question now
 

What is a logical question?

A logical question is a question that follows a clear and rational thought process, using reasoning and evidence to support the question. It is often used in scientific research to guide investigations and experiments.

How do you come up with a logical question?

To come up with a logical question, it is important to first identify a problem or topic that you want to investigate. Then, use critical thinking and logical reasoning to break down the problem into smaller, more specific questions. Consider the available evidence and use it to formulate your question.

Why is it important to ask logical questions?

Asking logical questions helps to guide the research process and ensures that the investigation is based on sound reasoning and evidence. It also helps to avoid bias and assumptions, leading to more accurate and reliable results.

What are the characteristics of a good logical question?

A good logical question should be clear, concise, and specific. It should also be based on evidence and use critical thinking to explore a problem or topic. Additionally, a good logical question should be testable and have the potential to lead to new insights or discoveries.

How can you improve your ability to ask logical questions?

Improving your ability to ask logical questions takes practice and critical thinking skills. It can also be helpful to seek feedback from others and to constantly question and challenge your own assumptions. Reading and learning about different research methods and techniques can also aid in developing the ability to ask logical questions.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
10
Views
879
  • Precalculus Mathematics Homework Help
Replies
5
Views
2K
  • General Discussion
2
Replies
65
Views
19K
  • Special and General Relativity
2
Replies
40
Views
2K
  • Set Theory, Logic, Probability, Statistics
Replies
19
Views
2K
Replies
4
Views
1K
  • Advanced Physics Homework Help
Replies
2
Views
1K
  • General Discussion
Replies
8
Views
3K
Replies
5
Views
927
  • General Discussion
Replies
16
Views
2K
Back
Top