It's not about sentences. It's about propositions. And propositions are proposed.

it doesn't look like we can know a falsehood. — TheMadFool

Indeed, it doesn't look like you can.

Indeed, it doesn't look like you can. — Olivier5

Ad hominem?! I'll ignore that for the time being. Let's focus on the issue at hand. You claim that we can know falsehoods. Expand and elaborate (if you can :wink: ).

I am not in the habit of talking to people who don't pay attention, sorry.

I am not in the habit of talking to people who don't pay attention, sorry. — Olivier5

I did pay attention and you're evading the question. Why? I wonder if it's because you can't prove your case.

Did you manage to understand that Fitch can be extended to false propositions, or not yet?

Did you manage to understand that Fitch can be extended to false propositions, or not yet? — Olivier5

It's not about me, it's about you. Also, why are we discussing this like little children? You made a claim: Fitch's argument can be extended to false proposition. A philosopher would justify that claim. I'm waiting...

You are a child, whether you are aware of it or not. You lack maturity. And you keep bitching petulantly about others. Stop bitching and start listening.

You are a child, whether you are aware of it or not. You lack maturity. And you keep bitching petulantly about others. Stop bitching and start listening. — Olivier5

Indeed, it doesn't look like you can. — Olivier5

Bitchin'? Me? :lol:

You are a child, whether you are aware of it or not. You lack maturity. And you keep bitching petulantly about others. Stop bitching and start listening. — Olivier5

By the way, I'm waiting for you to make an argument.

"We don't know that the earth is round"

and

"We believe that the earth is flat"?

The differences are so easy to point out that I don't see the sense in asking about it. — TonesInDeepFreeze

You remark is such an obvious way to make a mistake that I don't see the sense in pointing it out.

Argument made already.

https://thephilosophyforum.com/discussion/comment/603520

Argument made already.

https://thephilosophyforum.com/discussion/comment/603520 — Olivier5

¬p can be stated as "p is false".

q = ¬p

q→Kq

therefore

¬p→K¬p = all false propositions are known propositions.

This is elementary, really. Reason for which I did not write it down, not wanting to insult people's intelligence. InPitzotl got it immediately. So make an effort, calm your contrarian demons and for once, TRY and understand these ultra basic logical steps above. — Olivier5

$\neg p \rightarrow K \neg p \neq all \space false \space propositions \space are \space known \space propositions$. Sorry.

What are you sorry about, honey-bunny?

What are you sorry about, honey-bunny? — Olivier5

I'm sorry about your unsound argument. Again, let's stay focused on the problem at hand, shall we?

I'll try and help you if that's even possible since you seem so confident about your position.

Your claim: All false propositions are known propositions.

All false propositions. I need one example of a false proposition:

1. The earth is flat

This proposition, you claim, is known. Ok, let's put it down in words: I know the earth is flat. Does that make sense to you? It doesn't to me. If it does to you, how? please and thanks in advance.

This proposition, you claim, is known. Ok, let's put it down in words: I know the earth is flat. — TheMadFool

You know the proposition "the earth is flat". Otherwise you couldn't talk about it...

You know the proposition "the earth is flat". Otherwise you couldn't talk about it... — Olivier5

Knowing that there is a false proposition is not the same as knowing a false proposition.

Indeed, and I am talking about knowing that there is a false proposition. What are you talking about?

Indeed, and I am talking about knowing that there is a false proposition. What are you talking about? — Olivier5

This :point:

¬p→K¬p = all false propositions are known propositions. — Olivier5

How do you read "Kp"?

How do you read "Kp"? — Olivier5

Kp= Know that p.

So,

1. if p = the earth is round, Kp = know that (the earth is round) [No problem]

2. If p = the earth is flat Kp = know that (the earth is flat) [Problem]

Okay so you interpret Kp as "It is believed that p is true" or "It is known that p is true". For me it only means: "p is known", i.e. some people know about proposition p.

Why is
q -> Kq
being stated? — TonesInDeepFreeze

Because p -> Kp was stated.

No one believes that as a generalization for all q. — TonesInDeepFreeze

Apparently some people do. It's an antirealist position; the p doesn't exist until it's proposed, and it isn't true until you say it is, or some such thing.

Apparently some people do. It's an antirealist position; the p doesn't exist until it's proposed, — InPitzotl

On the contrary, it would be unrealistic to assume that there can exist English sentences that nobody speaking any English has ever composed or crafted... A realist view of the world does not imply that ideas nobody ever thought of exist already in some Platonic realm, waiting to be discovered.

On the contrary, it would be unrealistic — Olivier5

Antirealistic != unrealistic

?

↪InPitzotl
? — Olivier5

You're confusing "antirealist"/"realist" with "unrealistic"/"realistic"... the terms convey completely different things. A realist (in this particular sense) is someone who accepts the reality of something, usually external. An antirealist denies the reality of something. The "something" in this case is English sentences nobody has mentioned. You're objecting to an accurate term describing what you're doing, on the basis of the ill-conceived notion that it was commentary.

Okay so you interpret Kp as "It is believed that p is true" or "It is known that p is true". For me it only means: "p is known", i.e. some people know about proposition p. — Olivier5

What does "p is known" mean?

1. p = The earth is round

p is known = The earth is round is known (all ok)

2. p = the earth is flat

p is known = the earth is flat is known (? not ok)

What does "p is known" mean? — TheMadFool

As explained: some people know about the existence of proposition p.

As explained: some people know about the existence of proposition p. — Olivier5

You're equivocating. I'm out. Thanks for the interesting conversation. I learnt a lot from the exchange. Good day.