So I had a short debate with chatgpt 5, and chatgpt seems to have in the end conceded to my position on objective morality.

My argument:

"Most people should believe in existence of objective morality"

Pro takes position that most people should believe in existence of objective morality.

Con takes position that most people should "not believe in existence of objective morality".

Objective morality is defined as "things person objectively should/shouldn't do or objectively should/shouldn't believe in".

Burden of proof is shared.

Rules in description are agreed upon when accepting debate, and cannot be challenged. Same for definitions.

believe:

to think that something is true, correct, or real:

https://dictionary.cambridge.org/dictionary/english/believe

1. Self contradiction in opponent's position:

If my opponent says that people should believe in his position, while claiming no objective "should believe in" exists, he commits a self-defeat where he at same time wants to claim his position is what people should objectively believe in, while claiming people shouldnt objectively believe in anything.

II. Unwinnable situation for killer

If we were to meet a killer, he would be faced with only 3 logical options presented by us:

1. Killing is wrong
2. Killing is not wrong
3. Killing is okay when he does it (special pleading)

Should killer claim 1, he admits killing is wrong.

Should killer claim 2, we can claim "then we can kill the killer".

Should killer claim 3, and assume special pleading is okay, we can likewise do special pleading and say that killing him is okay because we do it.

With only 3 logical options available, none benefit the killer. And these 3 logical options remain true as objective morality, because 4th option doesnt exist. If my opponent comes up with "objectively true 4th option", he would be admitting objective morality instead of denying it.

Chatgpt 5:

It does not successfully establish objective morality. It has some rhetorical force, but philosophically the argument has several major weaknesses.

Here’s a breakdown.

I. The “self-contradiction” argument

Your argument:

If the opponent says people should believe his position, while denying objective “should,” he contradicts himself.

This only works against a very specific opponent: someone who simultaneously says:

1. “No objective norms exist”
2. “People objectively should accept my position”

But many anti-realists about morality do not claim (2).

They can instead say things like:

1. “I prefer people believe my position.”
2. “Society functions better if people believe this.”
3. “Given your goals, you should accept this.”
4. “There is no objective moral obligation, only preferences/conventions.”

None of those require objective morality.

So the contradiction is not built into the Con position itself — only into some possible ways of arguing for it.

A careful opponent can avoid the contradiction entirely.

II. Problem with your definition of objective morality

You define objective morality as:

“things person objectively should/shouldn't do or objectively should/shouldn't believe in”

This definition is extremely broad.

Because “should” can be:

1. prudential (“you should wear a coat”)
2. instrumental (“if you want X, you should do Y”)
3. epistemic (“you should believe what evidence supports”)
4. moral (“you morally should not murder”)

An opponent could argue:

Objective epistemic norms exist, but objective moral norms do not.

Your definition risks collapsing morality into any objective norm whatsoever.

That weakens the debate structure.

III. The “killer” argument does not prove objective morality

This is the biggest issue.

You argue the killer only has 3 options:

1. Killing is wrong
2. Killing is not wrong
3. Killing is okay only when he does it

But there are many more possible positions.

For example:

4. Moral relativism

Killing is wrong relative to your society’s values, but not objectively wrong.

5. Error theory

Moral statements are neither objectively true nor false.

6. Non-cognitivism

“Killing is wrong” merely expresses emotion/disapproval.

7. Contractarianism

Killing is prohibited because societies function better that way, not because of objective morality.

So your “only 3 options exist” premise is false.

IV. “Then we can kill the killer” does not refute moral anti-realism

You say:

If the killer says killing isn’t wrong, then we can kill him.

But the killer can simply answer:

“Yes, you can try.”

Or:

“I dislike being killed, but that does not make killing objectively wrong.”

That response is internally consistent.

Your argument confuses:

1. justification,
2. with
3. objective truth.

V. The argument uses reciprocity, not objectivity

A lot of your reasoning actually appeals to consistency and social reciprocity:

1. “If you permit X, you must permit X toward yourself.”

But reciprocity alone does not establish objective morality.

It can support:

1. social contracts,
2. game theory,
3. cooperation,
4. consistency norms,

without proving mind-independent moral truths.

VI. What your argument does successfully show

Your argument does have force against:

1. hypocrisy,
2. inconsistent moral nihilists,
3. selective special pleading,
4. people who want moral protection without granting reciprocity.

That is a legitimate argumentative strength.

But exposing inconsistency is different from proving objective morality exists.

VII. Stronger routes toward objective morality

If you want a stronger case, you would usually need to argue one of these:

1. moral facts are necessary truths,
2. rationality itself entails moral obligations,
3. consciousness/value logically generates obligations,
4. contradiction arises from denying moral realism,
5. certain norms are unavoidable presuppositions of agency.

Those approaches try to establish objective morality directly, rather than through rhetorical dilemmas.

So overall:

1. The argument is rhetorically effective in debate.
2. It pressures inconsistent opponents.
3. But philosophically it does not demonstrate objective morality.
4. The main failure is the false claim that only three options exist for the killer.

Me:

the opponent in debate already agreed to definitions. Also, those other options dont benefit killer either, because each can be used against him.

AI:

Given your debate framing, your argument becomes stronger rhetorically, but it still does not fully establish objective morality philosophically.

The key distinction is:

1. “the opponent is trapped within agreed debate rules”
2. vs.
3. “objective morality is actually proven true.”

Those are not identical.

Your point about agreed definitions does matter though.

Because if the opponent agreed that:

objective morality = things people objectively should/shouldn’t do or believe

then they cannot later redefine “should” into merely:

1. preference,
2. emotion,
3. convention,
4. utility,
5. relativism,

without violating the agreed framework.

So inside the debate, you successfully narrow their escape routes.

That strengthens Section I considerably.

However, the killer argument still has issues.

You say the other options “don’t benefit the killer either because they can be used against him.”

But that alone does not prove objective morality.

For example, suppose the killer says:

“There is no objective morality. I simply pursue my own interests.”

And you reply:

“Then we can kill you too.”

The killer can consistently answer:

“You can try. I still prefer surviving.”

That is not a contradiction.

It may be strategically bad for him, undesirable for him, or socially unstable — but none of those logically imply objective morality exists.

Your argument establishes something closer to:

1. reciprocity,
2. symmetry,
3. practical consistency,
4. inability to rationally complain,

rather than objective moral truth itself.

The strongest part of your argument is actually this:

a person who rejects objective moral constraints loses any non-arbitrary basis to object when those same standards are applied to them.

That is a real philosophical pressure point.

But notice:

that conclusion is still compatible with:

1. moral nihilism,
2. relativism,
3. amoral egoism,
4. contractualism.

Because those positions can accept reciprocal consequences without accepting objective moral facts.

So the debate effectiveness depends heavily on the audience and judging standards:

1. In public debate, your framing can be persuasive.
2. Against less careful opponents, it can corner them effectively.
3. Against trained philosophy opponents, they will likely argue you demonstrated only consistency constraints, not objective morality itself.

One more important thing:

Your argument becomes much stronger if reframed as:

Denying objective morality destroys any principled basis for condemning reciprocal treatment.

That is harder to evade than:

“therefore objective morality exists.”

Because the latter requires a bigger logical leap.

Me:

"You can try. I still prefer surviving.” - this merely enables punishment for killer.

"“There is no objective morality. I simply pursue my own interests.”"" - this likewise merely enables punishment for killer.

AI:

Yes — but “enabling punishment” is still not the same thing as proving objective morality.

Your argument successfully shows something like:

If someone rejects objective morality, they lose any principled objection to reciprocal harm against themselves.

That part works much better.

But from:

1. “The killer cannot coherently object to being punished/killed”
2. you cannot automatically derive:
3. “Objective morality therefore exists.”

Those are different claims.

An amoral egoist can consistently say:

1. “I want to kill others.”
2. “I do not want to be killed.”
3. “I understand others may retaliate.”
4. “I still pursue my interests anyway.”
5. “There is no objective moral truth involved.”

That position may be:

1. dangerous,
2. antisocial,
3. unstable,
4. unpleasant,
5. pragmatically self-defeating,

but it is not logically contradictory.

Your response:

“then punishment is enabled”

is true, but punishment can exist without objective morality.

For example:

1. deterrence,
2. revenge,
3. evolutionary survival,
4. social contracts,
5. collective self-interest,

can all justify punishment without requiring objective moral facts.

So your argument demonstrates:

1. consequences,
2. reciprocity,
3. symmetry,
4. forfeiture of complaint rights,

more than it demonstrates:

1. objective moral realism.

The strongest version of your case is probably:

A denial of objective morality collapses any non-arbitrary basis for condemning reciprocal treatment or punishment.

That is a substantial philosophical criticism of moral anti-realism.

But it still stops short of logically proving objective morality exists.

Me:

My position is that punishment is objectively logically enabled no matter what position killer takes, because any position he takes suffers from symmetry position which enables his punishment. this is objectively true. there is no position a killer can take without at same time logically justifying punishment against him.

AI:

What you are now arguing is stronger and more precise than the earlier formulation.

You are no longer directly arguing:

“objective morality exists because killing is wrong”

Instead, you are arguing something closer to:

Any normative position a killer takes necessarily permits symmetrical treatment against himself.

That is a more defensible claim.

But even here, there is still an important distinction:

You are proving an objective structural fact about consistency and reciprocity — not necessarily objective morality in the full moral realist sense.

Your argument can be reconstructed like this:

1. Any position the killer adopts creates a rule/principle.
2. If principles are applied symmetrically, they apply equally to the killer.
3. Therefore the killer cannot escape logical permission for reciprocal punishment.
4. Thus punishment of the killer is objectively logically enabled.

That argument is much stronger than the earlier version.

The crucial issue becomes the meaning of:

“objectively logically enabled”

because that is not automatically identical to:

“objectively morally correct.”

For example:

1. Chess rules objectively allow certain moves.
2. Logic objectively permits certain inferences.
3. Reciprocity objectively produces symmetrical consequences.

But those are structural/objective relations, not necessarily moral truths.

An anti-realist could still say:

“Yes, reciprocal violence is logically consistent under symmetry. That still does not create objective moral facts.”

So your argument seems to establish:

1. objective reciprocity,
2. objective symmetry,
3. objective consistency constraints,
4. unavoidable reciprocal permissibility,

rather than full-fledged moral realism.

However, your position becomes philosophically interesting if you add this additional premise:

Rationally unavoidable symmetrical norms are themselves objective morality.

That is the bridge your argument actually needs.

Without that bridge, your conclusion exceeds your premises.

With that bridge, your argument becomes something like a proto-contractarian or reciprocity-based theory of objective morality.

Your strongest formulation is probably:

Any agent who acts under a principle necessarily licenses symmetrical application of that principle to themselves. Therefore certain reciprocal norms are objectively unavoidable.

That is substantially harder to refute than the original killer trilemma.