Does objective Morality Exist?

If moral subjectivism were true, then there would be no genuine moral disagreement

Premise 2 & 3 are pretty self explanatory so ill cover premise 1 in more depth,if moral values were really just someone's preferences (which is what moral subjectivism suggests), so look at it like this. If joe says "abortion is wrong" & molly says "Abortion is right", if we translate these opinons it would be equivalent to joe saying "I disapprove of abortion" & molly would be saying "I approve of abortion", but if both are just saying approve/disapprove then is there a disagreement? The answer is no since moral debate, presumes moral disagreement, therefore genuine moral disagreements cant exist in a moral subjectivism world view

There is genuine moral disagreement

The 2nd argument is that moral subjectivism would render all of our moral judgements infallible 

Premise 1: If moral subjectivism were true, then all of our moral judgements would be infallible

This argument says moral subjectivism is incoherent

Premise 1: If moral subjectivism were true, then there would be true contradictions

premise 2: True contradictions are not possible

premise 3: Therefore moral subjectivism is not true

Ill elaborate on premise 1, suppose frank says "Its always wrong to eat meat" but suppose he also holds another view that could make eating meat acceptable like, "I also prefer not to starve to death" putting these 2 statements together we arrive to the conclusion that frank says "I never approve of eating meat and I sometimes approve of eating meat" This is obviously contradictory yet could be true in moral subjectivism

My opponent didnt explain what he means by genuine moral disagreement.

Obviously, two people can have different opinions and their opinions would still be subjective.

Objective, by definition, means independent of opinion and emotions. It needs to exist externally, outside of the brain and independent of it, so to say.

We still havent found morality existing anywhere outside of the brain, independent of the brain.

Saying that "if two people disagree, their opinion is objective" is by itself illogical statement that doesnt even care to explain how two opposite opinions can both be objective at the same time and exist independent of themselves.

This is an appeal to need logical fallacy. First, my opponent claims that if two people have opposite opinions, they are not in disagreement.  That is obviously false. Then he claims that objective morality exists because he apparently needs it to be able to disagree with people. I may need one million dollars in my pocket to be happy, but the existence of such need does not bring the cash into existence.

Definition of disanalogy:

A lack or failure of analogy.

Definition of analogy:

A similarity in some respects between things that are otherwise dissimilar.

Since my opponent didnt explan what is "genuine moral disagreement", this premise is an assumption, therefore, making the argument itself an assumption that doesnt need refuting.

Also, since my opponent conceded that there is moral disagreement, it follows that morality is indeed subjective and depends upon an opinion. Different opinions, different morality. Since moral debates depend upon arbitrary moral standard, and arbitrary moral standard depends upon opinion and brain, it follows that the core of morality is subjective.

This is not even close to truth, because people can change minds over time, or make unintended mistakes.

My opponent needs to say what he means by infallible. If he means incapable of making mistakes, thats obviously not true. People can make mistakes by not having enough knowledge when making decisions. If he means incapable of being wrong, that too would be false as people can change minds and standards over time.

Incapable of being wrong of falsified 

If he means incapable of being objectively wrong, he would need to first prove that moral judgments can be objectively wrong. However, that would still not prove objective morality. Saying that moral judgment can be objectively wrong is not proof of objective moral judgment. Likewise, saying that opinion can be objectively wrong is not proof of objective opinion existing.

Objective, to repeat again, means independent of an opinion.

Opinion cannot be independent of opinion, so moral judgment, being opinion, cannot be independent of an opinion at the same time.

Moral judgment is always based on arbitrary moral standard that is a result of an opinion, not independent of it. How can something be completely produced by brain and opinion at the same time be independent of it? It cannot.

No, there would not be true contradictions.

I can have one opinion. You can have opposite opinion. That is not any kind of "true contradiction". Its just two opposite things existing at the same time, but at a different place.

The opposite of owning a car is not owning a car, yet both happen at the same time, just with different places and different people.

One person can have two opposite opinions, and both opinions can exist at the same time, since they would be in different parts of brain.

The person would be contradicting himself, but it would not be any kind of true contradiction. It happens to people with multiple personalities. Consider it like two or more persons living in one brain.

Thanks for the fun first round.

Well apologies, by genuine moral disagreements, I mean people having differing views on ethical choices from each other, for example as I provided 2 people disagreeing on abortion

Well I believe your begging the question by assuming morality is a opinion

I showed how there cant be genuine moral disagreement

Ive searched the web and I cant find a "Appeal to need" fallacy

 "two people have opposite opinions they are not in disagreement" is false, which is why you shouldn't believe in subjective morality as that's what subjective morality points to

You then try to compare my example of "I need objective morality to have genuine moral disagreement" to "having a million dollars makes me happy, but that doesnt bring cash into existence" This is a disanalogy

So to prove this is a disanalogy id have to prove it isnt parallel, lets look at the 2 views

"I need one million dollars in my pocket to be happy, the need of happiness brings cash into existence"

and my view:

"Genuine moral disagreement exist, subjective morality cant account for this, therefore subjective morality is false"

I don't see how this is parallel at all and I implore the judges to see how vacuous this analogy is.

Now this is a non-sequitur, the conclusion doesn't follow. The premises are

1) People disagree on morals

2) Therefore objective morality doesnt exist

there's a moral law, which is the international law, or what Thomas Jefferson called the law of nature, or what the apostle Paul calls the law written on your heart (romans chapter 2). That law is objective morality and the only way to adjudicate between these 2 laws (the ally laws and the Nazi laws) was to say that the ally's moral view was closer to that objective moral view than the nazi culture

That doesn't make the opinion's infallible, it'd still be infallible under subjective morality

To imply a opinion on morality is wrong would be conceding the debate, since that'd make morality objective.

I dont really need to prove judgements can be objectively wrong

They can have two opposite opinions but they cant both exist & both be true

, same way how someone cant be artist, yet not be a artist at the same time.

So by genuine moral disagreement, you just mean moral disagreement.

You are yet to prove the morality which exists independent of an opinion. Given that two rounds have passed, I guess you just conceded that you cannot find morality that exists independent of an opinion.

No. You did not show that anywhere.

Oh, you should be very familliar with it, given that Christians use it the most.

Appeal to need - a claim that something exists because there is our need for it.

It is often used in teleology.

Another false claim. Nowhere did you provide any reason why people cant disagree if morality is subjective. You merely provided an example of people disagreeing, and then concluded that they were not disagreeing.

It is not a disanalogy. You said that if you need something, it exists. I simply stated that such logic is false, using analogy that has same logic in it.

And you are yet to prove that you need objective morality to have moral disagreement. So really, until you prove your premises, you have no case.

This is a strawman fallacy. The analogy was about your argument of need. I clearly pointed it out multiple times and said that just because there is a need, doesnt mean that the needed thing exists.

But to answer your  argument, you didnt prove that "subjective morality cant account for this". Your premise is just an assumption. Until you provide an actual reason to defend your premise, there is no case.

Further, since morality is an opinion and only exists thanks to opinion, it naturally follows that different opinions produce moral disagreements.

Subjective morality, depending upon opinion, would indeed produce moral disagreements due to different opinions.

Disagreement by definition means having different opinion. 

So my opponent's premise that people would not be able to have different opinions on morality if morality depended on opinion, is an obvious contradiction. Since my opponent's premise is self-contradicting, his argument falls apart.

Incorrect.

My opponent didnt respond to the argument I made:

"Different opinions, different morality. Since moral debates depend upon arbitrary moral standard, and arbitrary moral standard depends upon opinion and brain, it follows that the core of morality is subjective."

It was up to my opponent to point us to objective moral standard. The burden of proof is on him, since he is the one proving the positive claim that "objective morality exists".

You are yet to demonstrate that international law exists independent of an opinion, or that "law of nature" exists independent of an opinion.

You are again using an appeal to need.

"the only way to adjudicate between these 2 laws"

Again, just because you needed objective morality to objectively adjudicate, doesnt make objective morality true.

First, you would need to prove that you needed objective morality to subjectively adjudicate between two laws, or that subjective adjudication couldnt happen.

People can do subjective adjudication while thinking they are being objective, or lying that they are being objective.

Second, you would need to prove that objective adjudication actually happened. 

In subjective morality, there is obviously subjective adjudication. People dont need objective morality to judge others. To claim otherwise is nonsense, because then you would also be saying that Nazi judging Jews to death was done with objective morality.

My opponent doesnt understand what infallible means. It means incapable of being wrong or incapable of making mistake.

Even with subjective morality, people can still be wrong by their own or someone's elses standard, and they can still make mistakes, and they can still change their minds, obviously. Since morally wrong is subjective, its obvious that people can be subjectively wrong and subjectively right when dealing with morality.

To imply that opinion on morality is subjectively wrong does not in any way prove objective morality. It merely states subjective morality where certain things are wrong according to one standard, and right according to different standard. Thats what subjective morality is all about.

Well, you do. You claimed it.

You claimed:

"Premise: "Our moral judgements are not infallible"."

It was your premise, so you do need to prove it if you plan to get anywhere with this particular argument.

Obviously, in subjective morality, moral opinions can be wrong according to different subjective standard. This makes your premise false from the start.

Maybe you meant objectively infalliable, but that would require you to prove that moral opinion can be objectively wrong, since your premise is either that it can be objectively or subjectively wrong. Which one is it?

Of course they can. Different parts of brain have different opinions, sometimes even opposite opinions. I can like ice cream and you can not like ice cream. They are opposite opinions that exist at the same time, just in different places.

False analogy, since artist and non-artist would be forced to occupy same space, where opposite opinions can occupy different places, like different persons or different parts of brain.

The only thing that would be a contradiction would be two opposite things existing at the same time in same space. That doesnt exist in subjective morality, so your argument doesnt stand since it depended on that premise.