How to refute "a thing can be true and false at the same time"?

[Tomdstone]

~(~x) = x is the same as saying that “Not false = true” which is true, but has no bearing on the problem at hand. We’re dealing with the question of how to define something which is neither true nor false.

In any case, I don’t believe binary logic is the proper tool to use in this situation, especially since it results in a contradiction.

I mean, you could apply it, but it certainly doesn’t result in a satisfactory conclusion, and there are cleaner ways to skin the cat.

See this Wikipedia article: en.wikipedia.org/wiki/Liar_paradox

Of course, the conclusion is not satisfactory to those who deny that something can be both true and false because it defeats their argument. Further, I would not be interested in doing anything as cruel as skinning a cat.

 

[Peter_J]

In binary logic, if it is not true, then it is false. If it is not false, then it is true. So if it is not true, nor is it false, then it is both true and false.

Are we in binary logic?

 

[dshix]

Of course, the conclusion is not satisfactory to those who deny that something can be both true and false because it defeats their argument. Further, I would not be interested in doing anything as cruel as skinning a cat.

You don’t seem to be interested in actual dialogue. All you wish to do is trap the conversation into a corner where you’ve got it under control.

I fundamentally disagree with your assumption that binary logic is the only way to look at the situation, and I don’t appreciate your sarcasm.

 

[Peter_J]

Btw, if a person says “I am lying” and believes it (somehow), then he/she isn’t lying. So (in that particular case) we can maintain that the statement is false without any logical inconsistency. (That doesn’t help the thread much but I think it’s a nice side note.)

 

[Tomdstone]

I don’t appreciate your sarcasm.

You brought up the idea of skinning a cat. I disagree with that since it is quite cruel to do so. IMHO, it is better to be kind to animals, especially household cats.

 

[Tomdstone]

Btw, if a person says “I am lying” and believes it (somehow), then he/she isn’t lying. So (in that particular case) we can maintain that the statement is false without any logical inconsistency. (That doesn’t help the thread much but I think it’s a nice side note.)

Right. It is false that the person is lying, so what he says is true. But what he is saying is that he is lying. So it is both true and false that the person is lying.

 

[Peter_J]

Right. It is false that the person is lying, so what he says is true. But what he is saying is that he is lying. So it is both true and false that the person is lying.

No. In the case I’m talking about, it is false that the person is lying because he/she believes what he/she is saying (mistakenly).

With all due respect to Harvey Mudd, naturally.

 

[Tomdstone]

Here’s something else that is true and false at the same time:

Resist evil.

The catechism says to resist evil:
2265 Legitimate defense can be not only a right but a grave duty for one who is responsible for the lives of others.*

But God has commanded us not to resist evil: Douay Rheims Catholic bible:
“But I say to you not to resist evil” Matthew 5:39.*

 

[Peter_J]

Here’s something else that is true and false at the same time:

I’ve notice that more than once you’ve left off the qualifier " … and in the same respect", which is also not in the thread title (‘How to refute “a thing can be true and false at the same time”?’)

So is your point that the LoNC becomes nonsensical if that qualifier is omitted? If so, then we are in agreement.

 

[dshix]

You brought up the idea of skinning a cat. I disagree with that since it is quite cruel to do so. IMHO, it is better to be kind to animals, especially household cats.

Unless English is not your first language and you are completely unaware of the idiom “skin the cat”, then I am still not amused by your sarcasm.

 

[JuanFlorencio]

Here’s something else that is true and false at the same time:

Resist evil.

The catechism says to resist evil:
2265 Legitimate defense can be not only a right but a grave duty for one who is responsible for the lives of others.*

But God has commanded us not to resist evil: Douay Rheims Catholic bible:
“But I say to you not to resist evil” Matthew 5:39.*

I see now…

Tomdstone, all you need is a course on logic. First five classes will help you get clarity in your mind about all these things:

“Resist evil” and “Do not resist evil” are not true nor false. Those are commands, not propositions. I understand now why even after my post #2 you are still arguing.

 

[JuanFlorencio]

In binary logic, if it is not true, then it is false. If it is not false, then it is true. So if it is not true, nor is it false, then it is both true and false.

In “binary logic” there is no “both true and false” value.

 

[Tomdstone]

I see now…

Tomdstone, all you need is a course on logic. First five classes will help you get clarity in your mind about all these things:

“Resist evil” and “Do not resist evil” are not true nor false. Those are commands, not propositions. I understand now why even after my post #2 you are still arguing.

Let us phrase it this way:

Christians are obliged to resist evil.

This is both true and false.
True from the Catechism.
False from Scripture.

Catholics are obliged to call no man father.
True from Scripture.
False from common practice.

 

[dshix]

Let us phrase it this way:

Christians are obliged to resist evil.

This is both true and false.
True from the Catechism.
False from Scripture.

Catholics are obliged to call no man father.
True from Scripture.
False from common practice.

No, you are incorrect. You are conflating different things from different contexts.

The law of non-contradiction states that something cannot both be and not be at the same time, and in the same respect.

In your first example, I have no idea what you mean by saying that Scripture says that Christians are NOT obliged to resist evil.

In your second, you misunderstand what is meant by “call no man father”. See this Catholic Answers tract for a thorough explanation: catholic.com/tracts/call-no-man-father

 

[JuanFlorencio]

Let us phrase it this way:

Christians are obliged to resist evil.

This is both true and false.
True from the Catechism.
False from Scripture.

Catholics are obliged to call no man father.
True from Scripture.
False from common practice.

Oh, this is too harsh, Tomdstone. It just confirms that you need an elementary course on logics. You should look for one.

I will limit myself here to answer your comment from the point of view of logic.

Let’s suppose there is a commandment in the Catechism which says: “Christians are obliged to resist evil”. And let’s suppose also there is a commandment in the Scripture which says: “Christians are obliged not to resist evil”. Then, we can write the following two propositions:

• The Catechism says that Christians are obliged to resist evil.
• The Scripture says that Christians are obliged not to resist evil.

We also can write the conjunction of these two propositions:

The Catechism says that Christians are obliged to resist evil and the Scripture says that Christians are obliged not to resist evil.

If, as I said before, we assume that both simple propositions are true, then -according to the rules of logic- the conjunction is true, and I think that anybody with a little training on logic will be able to see that it is not logically contradictory.

Your other example can be expressed this way: “While the Scripture says that we should call no man father, Catholics’ common practice is to call the priest that way”. It is a conjunction of the two simple propositions:

• The Scripture says that we should call no man father
• Catholics use to call father to the priest.

And, assuming both propositions are true (which can be, of course), then the conjunction is also true, not contradictory.

 

[Tomdstone]

In your first example, I have no idea what you mean by saying that Scripture says that Christians are NOT obliged to resist evil.

Catholic Douay-Rheims Bible Matthew 5:39.
“But I say to you not to resist evil”

It is both true and false that Christians are obligated not to resist evil.
From Scripture Matthew 5:39: it is true.
From the Catechism: it is false.

 

[dshix]

Catholic Douay-Rheims Bible Matthew 5:39.
“But I say to you not to resist evil”

It is both true and false that Christians are obligated not to resist evil.
From Scripture Matthew 5:39: it is true.
From the Catechism: it is false.

Are you ignorant of the context of that verse? You even cut off the word “person” at the end of it.

Here is scripture it exhorts us to turn the other cheek to evil people rather than confronting them, as an exercise in charity.

It is evident that you have no idea how to correctly read or interpret scripture.

 

[Tomdstone]

Are you ignorant of the context of that verse? You even cut off the word “person” at the end of it.

Your argument is with the Roman Catholic Douay-Rheims Bible Matthew 5:39. The Roman Catholic Douay-Rheims Bible Matthew 5:39 “cut off the word “person” at the end”, not me.

 

[Tomdstone]

Here is something else that is both true and false at the same time:
If you do not hate your father, and mother, and wife, and children, and brethren, and sisters, yea and your own life also, you cannot be a disciple of Jesus.
It is true because it is a command of God in Scripture.
It is false because we should love our father, and mother, and wife, and children, and brethren, and sisters, yea and our own life also as a disciple of Jesus.

 

[JuanFlorencio]

I’m trying to solve this. Can someone help me prove that the Law of non-contradiction has to apply to EVERY situation?..

As the law of non-contradiction is a principle, the only way you have to prove that it applies to every situation is by showing the consequences of its negation. If your friend knows logic or has common sense, he will understand. But if he doesn’t, who will be able to do something with him?

Good luck!