Note, it's not drawn in standard form re categorical logic. — TheMadFool

No, it's not. It's a Venn diagram, which is what you asked for.

Whoever posted this question has never dealt with the latter

A, B, and C can't all be true, as that entails a contradiction. — Michael

Exactly. How do you solve it?

You can't deny that a fool is a ''good'' friend. He'll not harm you intentionally. Which means: All fools are friends.

You can't deny that a fool is a ''good'' enemy. He's stupid and in fact, if you're his/her foe, all you'll have to do is wait until he commits a fatal mistake. Which means: All fools are foes.

We also know No friends are foes. You can't deny that fools and foes are mutually exclusive classes.

A contradiction naturally follows. That's the paradox.

Exactly. How do you solve it? — TheMadFool

By rejecting one or more of the premises.

You can't deny that a fool is a ''good'' friend. He'll not harm you intentionally. Which means: All fools are friends.

No it doesn't.

You can't deny that a fool is a ''good'' enemy. He's stupid and in fact, if you're his/her foe, all you'll have to do is wait until he commits a fatal mistake. Which means: All fools are foes.

No it doesn't.

It's a Venn diagram, which is what you asked for. — andrewk

Your diagram allows for:

1. Some fools are not friends
2. Some fools are not foes

Both 1 and 2 contradict the truths of

All fools are friends
All fools are foes

The above are undeniable. See the post above.

So, the Venn diagram is flawed.

But you can't reject any of the premises. They are all true

But you can't reject any of the premises. They are all true — TheMadFool

They're not. There are more fools than I have friends. That's a fact. Therefore not all fools are my friends. There are more fools than I have foes. That's a fact. Therefore not all fools are my foes.

Furthermore, they can't all be true, given that it leads to a contradiction.

Both 1 and 2 contradict the truths of

All fools are friends
All fools are foes — TheMadFool

I don't know why you have suddenly come to believe this. But it's not correct, as Michael points out.

If you really want to grow your understanding, you'd be better off reading carefully what people say, and thinking about it, rather than just automatically arguing against it, because you have fallen in love with an idea you had.

Any fool is a good friend because a fool will not harm you intentionally: All fools are friends

Any fool is a ''good'' foe because a fool is easy to defeat: All fools are foes

Friends and foes are exclusive classes: No friends are foes

Can you deny any of these premises? If you can specify please.

Any fool is a good friend because a fool will not harm you intentionally: All fools are friends — TheMadFool

There are millions of fools in the world. I don't have millions of friends. Therefore not all fools are friends.

Any fool is a ''good'' foe because a fool is easy to defeat: All fools are foes

There are millions of fools in the world. I don't have millions of foes. Therefore not all fools are foes.

You're talking rubbish.

It isn't true that C) No friends are foes. I'm a friend to some people and I'm a foe to others. The premise is false and therefore any conclusions drawn from it are unsound.

Perhaps you misunderstood me.

All fools are friends doesn't mean that they actually have to be your friends, as in have to eat, talk, play with you. It's simply that they don't harm you intentionally that makes them friends.

All fools are foes doesn't they have to out to get you. It's just the fact that you can defeat them easily that makes them ''good'' foes. Anyway, the phrase ''A sucker is born every minute'' shows that people are always looking for the next fool to cheat and that's a inimical relationship.

So, you can't deny any of the original premises.

A person can't be a friend and a foe to the same person. That's what I mean

So X is a friend if X doesn't intentionally harm me, and X is a foe if I can defeat X easily.

Then if someone doesn't intentionally harm me and if I can defeat them easily then they are both friend and foe. You've defined "friend" and "foe" in such a way that they aren't exclusive classes.

With that interpretation, your argument can be translated as such:

A) Each fool a friend of someone S1
B) Each fool is a foe of someone S2
C) No foes of someone are also a friend to them

The conclusions:
D) No fools are a foe to anyone
E) No fools are a friend to anyone

I gather this is the intended interpretation of your argument. If not, explain how it isn't.

The conclusion doesn't follow from the premises; all that is necessary is that each friend S1 of each fool is not also a foe S2 to that fool. S1 =/= S2. Feel free to substitute cats and dogs into the argument form and derive nonsense.

You've defined "friend" and "foe" in such a way that they aren't exclusive classes — Michael

I haven't done that. Even if I have, the odd nature of a fool being a friend and foe stands out. It is a paradox.

See above.

I haven't done that. Even if I have, the odd nature of a fool being a friend and foe stands out. It is a paradox — TheMadFool

You're not making any sense.

You're not making any sense — Michael

That's the paradox

There is no paradox. You're just talking nonsense. @andrewk was spot on here.

Any fool is a good friend because a fool will not harm you intentionally — TheMadFool

You don't mind if they harm you unintentionally? You would be happy to have as a friend a knife-wielding psychotic that believes he's surrounded by orcs?

Even if that were the case, 'could be a friend' is not the same as 'is a friend', as Michael keeps pointing out and you continue to not understand.

Think of the kindest person you have heard of in this world that you have never met. Would they be a great friend if you knew them? Probably. Are they your friend? No, because you have never met them.

Friends and foes are exclusive classes: No friends are foes — TheMadFool

Really? In the trenches in the Great war, Helmut was Fritz's friend on the German side and Bill was Bob's friend on the British side. Yet Helmut and Fritz were Bill and Bob's foes and vice versa.

Have you never heard the phrase 'my enemy's enemy is my friend'? It's a gross over-simplification but it should at least give you pause for thought.

There is no paradox — Michael

Really? But you haven't been able to deny any of the premises in my argument:
1. All fools are friends
2. All fools are foes
3. No foes are friends

If you can't do so, the paradox holds.

You don't mind if they harm you unintentionally? — andrewk

Well, the general perception seems to be that intent in crimes is a crucial element in deciding the punishment. A simple example in law is the distinction ''death from negligence'' and ''premeditated murder''. Also, ''sorry, it was accidental'' is high up in the world of apologies.

Really? In the trenches in the Great war, Helmut was Fritz's friend on the German side and Bill was Bob's friend on the British side. Yet Helmut and Fritz were Bill and Bob's foes and vice versa — andrewk

Yes, but Fritz wasn't Helmut's foe and friend. Also, Bill wasn't Bob's friend and foe.

I give up. You appear determined to hold on to your belief regardless of all considerations. I wish you joy of it.

I give up. — andrewk

:)