Instigator / Con
Casey_Risk's avatar
0
Casey_Risk
1485
rating
4
debates
50.0%
won
Topic
#5613

If God exists, then morality is objective

Status
Voting

The participant that receives the most points from the voters is declared a winner.

Voting will end in:

00
DD
:
00
HH
:
00
MM
:
00
SS
Tags
Morality
Ethics
Parameters
Publication date
Last updated date
Type
Standard
Number of rounds
4
Time for argument
Two weeks
Max argument characters
10,000
Voting period
One month
Point system
Multiple criterions
Voting system
Open
Contender / Pro
Socrates_had_a_baby's avatar
0
Socrates_had_a_baby
1500
rating
2
debates
75.0%
won
Description

Resolution: If God exists, then morality is objective.

Definitions:
God - the omniscient, omnipotent, sentient creator of the universe who gives moral commandments to his followers and/or humankind in general
Morality - a system that prescribes what is right, wrong, good, and evil
Objective - derived from facts and valid logical deductions; provable. | Antonym of subjective

Pro will have the primary burden of proof in this debate. As such, I, as Con, will waive the first round. In turn, Pro must waive the last round. Violation of this rule ought to result in a conduct point penalty. Forfeiting a round also ought to result in a conduct penalty.

Thank you, and may the better debater win!

Round 1
Casey_Risk's avatar
Casey_Risk
Con
#1
Per the format of this debate, I waive this round. 
Socrates_had_a_baby's avatar
Socrates_had_a_baby
Pro
#2

Introduction:
When we look out at the world we needn't look far to discover that people take the objectivity of morality for granted, and if they didn’t, the basic fabric of society would quickly splinter apart. That is to say, the colloquial understanding of morality is that it exists as an independent standard about human affairs, it can be appealed to, and it is efficient in settling disagreements about issues of justice. To demonstrate this, consider this passage from C.S. Lewis: 

“Everyone has heard people quarreling. Sometimes it sounds
funny and sometimes it sounds merely unpleasant; but how-
ever it sounds, I believe we can learn something very impor-
tant from listening to the kind of things they say. They say
things like this: ‘How’d you like it if anyone did the same to
you?’—‘That’s my seat, I was there first’—‘Leave him alone,
he isn’t doing you any harm’—‘Why should you shove in
first?’—‘Give me a bit of your orange, I gave you a bit of
mine’—‘Come on, you promised.’ People say things like that
every day, educated people as well as uneducated, and children
as well as grown-ups.
Now what interests me about all these remarks is that the
man who makes them is not merely saying that the other man’s
behaviour does not happen to please him. He is appealing to
some kind of standard of behavior which he expects the
other man to know about. And the other man very seldom
replies: ‘To hell with your standard.’ Nearly always he tries to
make out that what he has been doing does not really go
against the standard, or that if it does there is some special 
excuse. He pretends there is some special reason in this partic-
ular case why the person who took the seat first should not
keep it, or that things were quite different when he was given
the bit of orange, or that something has turned up which lets
him off keeping his promise. It looks, in fact, very much as if
both parties had in mind some kind of Law or Rule of fair play
or decent behaviour or morality or whatever you like to call it, about which they really agreed.” 
What we see here is that people behave as if there is some sort of agreement about what Right and Wrong really are, and when there are disagreements they appeal to something like a Law of Human Nature, and they use their moral intuitions, the common law and the Church (when relevant) to decide who is more congruent with the Law of Human Nature. 


     This passage leads right into my first point, which is that morality must exist independently of any individual’s reason, otherwise, it wouldn’t be able to stand apart as a standard capable of settling disagreements. If morality were subjective all the way through, one person’s claim of justice would be just as true as another person’s, and if those two people got into a quarrel there would be no way of telling who was in the right and who was in the wrong. To draw upon a metaphor, imagine if we had no agreements about the basic axioms of mathematics, such as the law of addition, Euclid’s geometric axioms, Axiom of Induction, etc., if different mathaticians used different axioms they would never be able to agree upon anything, build rockets, cars, etc., it wouldn’t matter how consistent they were with their own set of rules if they all didn’t take the same set of assumptions for granted about the rules of the universe. The only real difference between the Law of Human Nature, and the laws of nature, is that a planet could not choose whether it obeyed the law of gravitation or not, but a man could choose either to obey the Law of Human Nature or to disobey it. In summary, the measuring stick of morality needs to be independent of the thing measured.
     In addition to the commonsensical use of morality, we can also deploy the logical argument of Reductio ad Absurdum to show the logical contradictions we would be led to accept if we considered morality to be subjective. Imagine who absurd it would be if someone said, “In my opinion, I just don’t like the Nazi party.” If we accepted subjective morality, then we would have no way of condemning the Nazis beyond our own opinion. Instead, we want to be able to say that the Nazis were really wrong and that they transgressed a law of the universe, which says that there is something wrong about putting Jews in ovens. Otherwise, we can accuse the Nazis of no more than being overly zealous patriots of Nazi Germany. And the Neroberg trials (where we tried Nazi doctors like Dr. Josef Mengele for conducting inhuman experiments on the Jews) should have never taken place, and no Nazi should have been held accountable for putting Jews in ovens. Because after all, Nazi German made laws that it was acceptable to imprison and torture Jews, so if subjective morality was true then Germans were actually doing the moral thing by following the law at the time! 
The title of this debate is “If God Exists, then Morality is Objective,” which implies that there might be other kinds of possible worlds where morality is subjective. Since we are not debating the modal possibility of other words, we must give reasons for the ways in which morality is objectively grounded in the world we find ourselves in. The thesis of this argument is that morality is grounded in the laws of nature of the created order, platonic ideals, and God. Let’s start with the laws of nature:
  1. There are vast symmetries between the neurological states of humans. Our wiring as homo sapiens is such that the release of certain neurotransmitters in the brain creates the phenomenological experience of joy or suffering, and this does not change from human to human. The rise of Serotonin levels roughly corresponds with emotions like joy, and the rise of hormones like cortisol corresponds with emotions like stress. Due to these symmetries of brain chemistry, the US constitutional right for “the pursuit of happiness” also depends on symmetrical circumstances that give rise to the neurotransmitters of happiness.  For one, consistent serotonin levels require that Maslow's needs are met, like food, water, and shelter, and the basic physical hierarchy there also other psychological needs, like purpose, community, meaning that need to be met to obtain a happy life over the course of one’s life. Because these needs do not vary to a high degree from person to person, so metaethical values need to be held to protect the rights, liberties, and autonomy of humans. For example, if property rights were deprived of people, this would thwart their ability to garner resources and would lead to a loss of food, water, and shelter, which would end in human suffering. In summary, since humans are largely built the same, they require largely symmetrical treatment, and to say that metaethical values are subjective is to say that there are no universal guiding principles we can use to predict human behavior or to maximize human happiness. Morality is consistent from culture to culture and from person to person because the laws of nature that dictate the structure of the human psyche are universal. To say that morality is subjective is to deny the objectivity of the laws of nature. 
  2. If you know anything about mathematics, you know that the majority of mathematicians at the research level are something akin to Neo-platonists. Whether or not the Platonic realm is true in actuality, the way that the theory of Platonism explains the ways that math is discovered, appears to be independent of human minds, and yet is unreasonable effective at solving real problems makes Platonism a highly attractive philosophical explanation of mathematics. For instance, the statement "2+2=4" seems true regardless of cultural background, time period, or individual belief. However, no one has ever seen the number “4,” or can prove that any numbers exist objectively. Numbers are instrumentally highly useful at solving problems, but they are not discovered empirically. I say all this to suggest that morals as treated with the same kind of ontological status as Platonic ideas prove to be highly explanative as a philosophical theory. The kind of moral world that humans find themselves in tends to be one where we have real claims to moral rights and can suggest when moral wrongs have transgressed. So for example, children at the early ages of three and four years old have been shown in studies to act as “intuitive lawyers.” These children are capable of judging the intent of the actors and are even able to draw a distinction between what is referenced in the law and the difference between a mistake of fact vs. a mistake of law (Levine, Leslie, & Mikhail, 2018). This is a highly developed sense of moral judgment that has been built into nearly every legal system. If morality was simply a social construct that was conditioned by society or by parents, then it would be nearly impossible for children at these ages to be able to make such intuitive moral judgments. This implies that there is something of a universal moral grammar, which is the basic idea that there might be an innate basis for our moral judgments. Chomsky thought that we all had an innate linguistic grammar and that all languages had the same deep grammatical structure. If morals are innate, but we are able to contest about which morals are more or less preferable, then the moral world turns out to be discovered by the human mind, but is recapitulated through language, and ultimately by the laws we adopt as a society. In conclusion, the pervasive and objective nature of morality is best described as mathematics and like that of the platonic forms.
  3. In many religious traditions, God is seen as the ultimate standard of goodness. For instance, in Christianity, God's nature and will define what is morally right and wrong. This concept aligns with the idea of the "summum bonum," where God embodies the highest form of good that all other values and actions are measured against.

Round 2
Casey_Risk's avatar
Casey_Risk
Con
#3
I would like to thank my opponent for accepting this debate. May it prove to be an intelligent and thought-provoking discussion!

The Argument From Consequences
Imagine, for a moment, that a friend came up to you distraught, saying, "I just found out that some people believe that tastes in books, music, television, and film are subjective, not factual! How could this be?"

You respond, "Well, of course they are. Why wouldn't they be?"

Your friend says, "Why, if opinions on film were truly subjective, then all standards of quality would disintegrate! The Shawshank Redemption would have just as much claim to being the best movie ever made as The Room! Clearly, that can't be true, so whether a movie is good or bad must be universal and objective."

I think it's clear what the problem with this argument is, and yet many, including my opponent, use essentially the same line of attack to try and prove moral realism. Really, this is just a logical fallacy known as an Appeal to Consequences -- the idea that some fact must be wrong because if true, it would lead to an undesirable outcome. My opponent uses this sort of argument several times, saying, for instance:

Imagine who absurd it would be if someone said, “In my opinion, I just don’t like the Nazi party.” If we accepted subjective morality, then we would have no way of condemning the Nazis beyond our own opinion. Instead, we want to be able to say that the Nazis were really wrong and that they transgressed a law of the universe, which says that there is something wrong about putting Jews in ovens.
The problem with this line of attack is, even if I take the argument presented completely at face value, it doesn't actually prove that morality is objective -- i.e. that there are moral facts. All it does is say that the statement "The Nazis were evil" would not be factual if morality is subjective, which is undesirable in my opponent's view. Perhaps it would be more desirable for such a statement to be factual and universally true, but that doesn't make it so. At best, Pro argues that morality must be objective because we should want it to be so, for it would lead to desirable results. At worst, he assumes that "The Nazis were evil" is already factual to begin with, which is just Begging the Question, another logical fallacy.

Other quotes from my opponent that use this same sort of unsound reasoning:

[M]orality must exist independently of any individual’s reason, otherwise, it wouldn’t be able to stand apart as a standard capable of settling disagreements. If morality were subjective all the way through, one person’s claim of justice would be just as true as another person’s, and if those two people got into a quarrel there would be no way of telling who was in the right and who was in the wrong.
This assumes that some objective way of telling who is right must exist, but this is unsupported.

[T]o say that metaethical values are subjective is to say that there are no universal guiding principles we can use to predict human behavior or to maximize human happiness.
This is akin to saying, "If Islam is not the true religion, then there would be no way of explaining how Muslims could refrain from eating delicious bacon." Clearly, Muslims don't eat pork because they believe God commands them to not do so. The actual existence of Allah is not necessary to explain this. Most humans believe in some form of morality, so it only makes sense that they would act according to some moral principles. We can still predict human behavior and measure human happiness even if there are no moral facts.

Axiomatically Incorrect
My opponent makes reference to mathematical axioms and says that morality works in a similar way. However, this argument only weakens his case, rather than strengthening it. Axioms are statements which are taken to be true because they serve as a basis for reasoning but cannot be proven. It is a foundational truth of both mathematics and logical reasoning in general that some things must simply be taken for granted, or else we would never be able to prove anything at all. For instance, the reflexive property, which in mathematics states that a number is always equal to itself, is not itself provable, but is merely assumed to be true.

Moral objectivism cannot be proven by simply taking it as axiomatic, for again, that would merely be begging the question. To argue that we ought to come to an agreement on moral axioms for the betterment of society is to say that morality would not objectively exist if we did not first start with the assumption that it does.

Hume's Guillotine
The strongest points my opponent makes involve similarities among the moral systems of human cultures and the apparent innateness of human morality. There are a few points I could make in this regard. For one thing, I believe that there are cultural differences in moral systems which shed serious doubt on the validity of this argument. For instance, virtually everyone everywhere would agree that rape is morally wrong, and a grievous wrong as well. However, what exactly is rape? It sounds like a simple question, but various cultures across the world and across time have viewed things very differently. Until relatively recently, marital rape was not a crime punishable by law throughout most of the world, and in some parts of the world, it is still perfectly legal, mainly because the people living in those legal jurisdictions where it is legal do not consider it to be a wrong. Rather, they believe that a man has a fundamental right to sex with his lawfully wedded wife which is more important than and outweighs her own right to bodily autonomy. This provides evidence that morality is shaped just as much as, if not more so, by culture rather than anything innate.

However, I think there is still a more fundamental point being missed here. I think my opponent's arguments are sufficient to demonstrate that morality exists in general, but that is not the topic of this debate. It is up to Pro to prove, not just that morality exists, but that it is objective -- that there are moral facts that are true and independent of human beliefs, feelings, or perceptions. In other words, if rape is objectively wrong, it must be wrong not merely because humans believe it to be wrong, but because it is actually so. In deferring to human beliefs and intuitions, Pro fails to prove that these beliefs are factual, and falls victim to the classic fallacy of assuming an 'ought' from an 'is'. One cannot validly derive a moral statement merely from descriptive statements.

This is the real crux of my argument, so let me deliver it as plainly but as completely as I can.

  1. Any moral statement either is, or has an equivalent, ought statement. For instance, to say that 'Theft is wrong' is equivalent to saying that 'One ought not commit theft.'
  2. No ought statement can be validly derived merely from descriptive statements ('is statements'). This is widely accepted to be true among philosophers.
When we put these two statements together, however, we arrive at a stunning conclusion. If it is possible to prove a moral statement, then we can prove an ought statement (1). However, to prove that ought statement, we must first have an ought statement in the premises (2). But, in order to prove that statement in our premises, it must be derived from a logical argument that also has an ought statement in the premises. And then, we would need to prove that ought statement as well. Either we end up in an infinite loop of circular logic, or an infinitely long chain of justifications that has no end point. Either way, it is an inherently invalid argument. However, to derive an ought statement merely from 'is statements' is also logically invalid. Therefore, we find that it is impossible to prove any ought statement, which means that it must be impossible to prove any moral statement at all. Moral objectivism is quite literally impossible unless we take at least one moral statement to be axiomatic. However, as already discussed, to do so would merely be begging the question, itself a logical fallacy. Therefore, morality cannot be objective.

Conclusion
My opponent's case is fundamentally backwards -- it relies on first assuming that objective morality exists, and works backwards from there. However, it fails to actually prove its existence or clearly describe its origins, and relies on classic logical fallacies, rendering the whole argument unsound. He has not been able to meet his burden of proof.

Thank you for reading! I now yield the floor.
Socrates_had_a_baby's avatar
Socrates_had_a_baby
Pro
#4
Forfeited
Round 3
Casey_Risk's avatar
Casey_Risk
Con
#5
Unfortunately, my opponent has been unable to respond in time. I shall await his arguments.
Socrates_had_a_baby's avatar
Socrates_had_a_baby
Pro
#6
reductio ad absurdum

Let’s run with my opponent’s analysis about the treatment of the Nazi party. Let’s grant for the moment that morals are entirely subjective. In this hypothetical world, according to the morals established in 20th-century Germany, it was right to dehumanize Jews, deport them to concentration camps, and mass exterminate them. In fact, People like Bonhoeffer, Corrie Ten Boom, and other decenters against the Nazi law were wrong for disobeying Nazi law! 

If subjective morality is true, then there is nothing that the rest of the world can say about their subjective island of anti-Semitic ethics. Upon winning the war, we should never have interrupted their concentration camps… we should never have held the Nuremberg trials and tried Nazis for torturing Jews… Instead, we should have allowed them to keep torturing Jews. How dare we interfere with their cultural view of the world!  We should have accepted their fun-anti-Semitic-cultural-quirk. Right? Because it’s not our place to judge the Nazis! 

The statement "The Nazis were evil" is not factual, it only leads to undesirable consequences. 

But how can it lead to undesirable consequences if the majority of leading Germans in the Nazi government believed it to be desirable? Undesirable for the Jews maybe at the time. Why is it even an undesirable consequence for me? I’m not Jewish; so if I affirm subjective ethics and I live in 21st-century America with the norms of my era, then how can I compare that to the norms of Nazi Germany? The moment you start asking the question, “undesirable for whom,” you begin to see that if one class of human beings goes unprotected, then the rest of the human race is in danger of losing those same rights. You might remember these words echoed by that of Martin Luther King Jr, “Injustice anywhere is a threat to justice everywhere.” In other words, the rest of the world recognized that the Jews deserved human autonomy and dignity just like any other race. But why would we care that all human beings are treated equally unless there are ethics that extend across the human race? 

This is percisely because there are certain ways we should treat all human beings regardless of gender, class, race, etc., and this implies that there are also universal rules about how we treat humans that captures this symmetry of fairness. 


The symmetries of biological wiring implys objective morality:

I think it is convenient that you bypassed one of the strongest arguments for objective morality that I presented in my last post. I will present it again in brief so it doesn’t get lost, but for the full treatment please see my first post: 

Human beings share similar biological and neurological structures, which produce consistent experiences of joy and suffering through the release of neurotransmitters like serotonin and cortisol. These experiences rely on the fulfillment of basic needs—food, water, shelter, and psychological well-being—that are largely universal across individuals. Therefore, morality must be objective, grounded in these shared human requirements. To claim morality is subjective is to ignore the natural laws that dictate human well-being. Objective moral principles are necessary to protect the rights and autonomy that enable human flourishing. 


A rebuttal to this argument against objective morality can address both the cultural variability of moral judgments and the interpretation of moral principles:
  1. Cultural Differences Don’t Negate Objective Morality: The fact that different cultures may have varying interpretations of what constitutes a moral wrong, such as rape, does not necessarily invalidate the existence of objective moral principles. Objective morality suggests that certain actions are intrinsically right or wrong, regardless of how societies interpret or enforce these standards. Cultural practices and legal definitions may deviate from moral truths, but these variations reflect differences in perception rather than a lack of moral universals. For example, societies that once tolerated slavery or marital rape do not undermine the claim that these practices were always objectively wrong; rather, they illustrate how moral understanding can evolve and better align with objective truths over time.
  2. Innate Moral Awareness: The innateness of human morality, which many cultures share despite differences in legal frameworks or practices, points to underlying moral constants. For instance, even in societies where marital rape was legally permitted, this doesn’t necessarily mean it was morally accepted by all individuals. Laws often reflect power structures or social norms that may not correspond to deeper, universal moral instincts. The widespread recognition of concepts like harm, fairness, and bodily autonomy across cultures suggests that objective moral values exist, even if the specific application of these principles varies.
  3. Cultural Evolution and Moral Progress: The evolution of legal and moral attitudes toward issues like marital rape can actually support objective morality by showing that societies move closer to recognizing moral truths over time. For example, the global shift toward criminalizing marital rape reflects a growing consensus that bodily autonomy is a fundamental moral principle that transcends cultural and temporal differences. This progression suggests that humanity, through reason and empathy, can better grasp objective moral truths as they develop a more consistent understanding of what it means to respect human dignity.
Ah yes, David Hume’s famous "is-ought problem," which asserts that you cannot derive an "ought" (a moral statement) from an "is" (a factual statement). This is a common argument against moral objectivism.
  1. The Naturalistic Fallacy Can Be Challenged: The is-ought problem is not universally accepted as fatal to moral reasoning. Some moral realists argue that certain facts about human nature, well-being, or social cooperation imply moral obligations. For example, Sam Harris and others have suggested that we can derive "oughts" from facts about human flourishing—just as we derive medical prescriptions from facts about human health. This returns us to my point about the symmetries in human brain chemistry that require symmetrical external environmental conditions for happiness to arise, and this requires symmetrical ethics. 

Round 4
Casey_Risk's avatar
Casey_Risk
Con
#7
Thank you, Pro, for your arguments.

The Meaning of Subjective Morality

My opponent writes:

Let’s run with my opponent’s analysis about the treatment of the Nazi party. Let’s grant for the moment that morals are entirely subjective. In this hypothetical world, according to the morals established in 20th-century Germany, it was right to dehumanize Jews, deport them to concentration camps, and mass exterminate them. In fact, People like Bonhoeffer, Corrie Ten Boom, and other decenters against the Nazi law were wrong for disobeying Nazi law! 
No. None of this is true. Not only is this false, it is obviously false to anyone who actually understands what it means for morality not to be objective. Moral good cannot exist without moral evil, nor can wrong exist without right. To say that morality is subjective and then say that following the law must be the inherently right thing to do, and breaking the law is wrong, is an immediate and clear self-contradiction.

Furthermore, I absolutely DO believe that the Nazis were morally evil for committing a genocide. I apologize if this was not obvious from the way I worded my arguments in my opening, but I also did not expect my opponent to make this mistake. My position, moral anti-realism, simply states that there are no moral facts. In other words, it simply means that moral statements such as "Theft is wrong" are not provably true in the same way that statements like "2 + 2 = 4" and "Berlin is the capital of Germany" are provably true. Perhaps moral objectivism may seem to be obviously correct in my opponents perspective, but in this debate, he is actually required to demonstrate its proof, rather than rely on what intuitively seems to be so.

My opponent also quotes me as saying,

The statement "The Nazis were evil" is not factual, it only leads to undesirable consequences. 
But that's not quite what I said. I pointed out that Pro was using an appeal to consequences to try and prove moral realism by saying that moral anti-realism is uncomfortable and defies our intuitions. However, there are plenty of true, yet highly surprising and unintuitive facts.

This is percisely because there are certain ways we should treat all human beings regardless of gender, class, race, etc., and this implies that there are also universal rules about how we treat humans that captures this symmetry of fairness. 
Yet another example of circular reasoning -- Pro is just starting with the assumption that morality is objective, and then using that as an argument.

The Argument From Biology

Human beings share similar biological and neurological structures, which produce consistent experiences of joy and suffering through the release of neurotransmitters like serotonin and cortisol. These experiences rely on the fulfillment of basic needs—food, water, shelter, and psychological well-being—that are largely universal across individuals. Therefore, morality must be objective, grounded in these shared human requirements. To claim morality is subjective is to ignore the natural laws that dictate human well-being. Objective moral principles are necessary to protect the rights and autonomy that enable human flourishing. 
The argument here is flawed. Yes, obviously humans have certain needs that must be met in order to survive and reproduce. I don't deny that. But, what about human existence is inherently good? I realize that may sound like a strange question, but I don't ask it for no reason. The point of philosophy is to explore ideas, to challenge everything that we believe dearly and examine whether it really is true.

Remember, in this debate, morality is defined as: "a system that prescribes what is right, wrong, good, and evil". If morality exists and is objective, from where does it come? We as humans base our moral standards on our own experiences and intuitions. We see everything through our own perspective, which is why our morality is focused on our own species, but this viewpoint is inherently subjective, rather than objective. My opponent is essentially starting with the assumption that "That which allows humans to survive and thrive is morally good" without having robustly proven this first. Again, even if it seems intuitively right, and could be taken as a given in an ordinary debate, in this particular kind of debate, it really does need to be proven.

A Cultural Contradiction
In response to my argument about cultural values varying across the world, my opponent makes a few different points. First, he says,

Objective morality suggests that certain actions are intrinsically right or wrong, regardless of how societies interpret or enforce these standards. Cultural practices and legal definitions may deviate from moral truths, but these variations reflect differences in perception rather than a lack of moral universals. For example, societies that once tolerated slavery or marital rape do not undermine the claim that these practices were always objectively wrong; rather, they illustrate how moral understanding can evolve and better align with objective truths over time.
He also goes on to say,

The evolution of legal and moral attitudes toward issues like marital rape can actually support objective morality by showing that societies move closer to recognizing moral truths over time. For example, the global shift toward criminalizing marital rape reflects a growing consensus that bodily autonomy is a fundamental moral principle that transcends cultural and temporal differences. This progression suggests that humanity, through reason and empathy, can better grasp objective moral truths as they develop a more consistent understanding of what it means to respect human dignity.
Consider these two points at once for a moment. For one thing, Pro says that just cultures and societies can uphold incorrect beliefs, but also that the change in society towards ending the legality of marital rape is an argument for moral objectivism. But I say, how does Pro know that society is moving in the right direction? Clearly, Pro and I would both agree Germany was moving in the wrong direction when it allowed the Nazis to rise to power and enact their laws that oppressed and murdered millions of Jews. I certainly believe that rape, including marital rape, is wrong, but on what basis does my opponent say it is wrong, given that he himself admits that mere belief in its immoral nature is not proof? 

Perhaps it is true that there is a widespread belief in basic principles like "harm, fairness, and bodily autonomy", but the fact that these principles are applied in such inconsistent, and sometimes wildly different, ways really undermines the argument that moral statements are universal. Furthermore, just because nearly everyone believes in such principles, does not make them factual, which brings me back to Hume's guillotine.

We Debate, Therefore We Ought to Debate
This really is the crux of my argument. I consider it to be my strongest and most important argument, enough to prove my case on its own. Even if voters don't agree with any of my other points, I ask them to strongly consider this line of reasoning.

In my opening, I made a pretty clear logical argument as to why moral statements cannot be factual, meaning that moral realism cannot be true. My opponent makes only a brief rebuttal, which leaves a lot to be desired.

Some moral realists argue that certain facts about human nature, well-being, or social cooperation imply moral obligations. For example, Sam Harris and others have suggested that we can derive "oughts" from facts about human flourishing—just as we derive medical prescriptions from facts about human health. This returns us to my point about the symmetries in human brain chemistry that require symmetrical external environmental conditions for happiness to arise, and this requires symmetrical ethics. 
This does nothing to substantially address the points I laid out in my section "Hume's Guillotine". A certain medical prescription may be the right course of action given that one's aim is to improve a person's health. But this sort of rebuttal requires that one accept the given that we must aid humanity in the first place. Given that one's aim is to help humanity flourish, certain things may be beneficial or harmful, but that means starting with the assumption that what helps humanity flourish is necessarily and inherently morally good -- and that, yet again, is begging the question.

Logically speaking, however, the truth that an 'ought' cannot be derived from an 'is' is self-evident. You cannot validly conclude that X exists if X is not defined and included within your premises. I can say that physical assault is bad for one's mental and physical well-being, and certainly I am right about that, but to conclude that it is morally wrong is to conclude something not contained within the premises at all. I can demonstrate:

  • P1: If assaulting someone causes physical harm, it is detrimental to their health. (P → Q) 
  • P2: Assaulting someone causes phyisical harm. (P)
  • C: One ought not commit assault (∴ R)
As this tree proof generator shows, this sort of argument is inherently invalid. My proof for moral anti-realism holds, and it is therefore impossible for morality to be objective.

Conclusion
While my opponent has tried to lay out the case for the existence of objective morality (curiously hardly mentioning God at all in the process), his arguments have been filled with logical fallacies. On the other hand, I have shown a clear argument for moral anti-realism that relies only on basic logical reasoning and is accessible to anyone. Pro has been unable to meet his burden of proof, and so I ask voters to vote for Con! Thank you for taking the time to read this debate.
Socrates_had_a_baby's avatar
Socrates_had_a_baby
Pro
#8
Thank you, Con, for your arguments.

The Nature of Moral Anti-Realism
Your argument rests on the claim that moral statements such as "theft is wrong" or "genocide is evil" cannot be true in the same sense as mathematical or scientific facts. However, this treats moral claims as if they are purely descriptive, reducing them to mere expressions of subjective opinion or emotional reactions. This misunderstanding conflates epistemology (how we come to know moral truths) with ontology (the nature of moral truths). Even if we disagree on the methods of discovering moral truths, this does not mean such truths do not exist. The mere fact that moral disagreements exist does not prove that morality is subjective; disagreements about the nature of reality do not imply that reality itself is subjective.
reductio ad absurdum: Subjective treatment of Nazi morality

You suggest that in a world where morality is subjective, we would have to accept that the Nazis were right according to their moral code. However, the conclusion that subjective morality implies moral nihilism is unwarranted. To claim that moral anti-realism does not deny the moral wrongness of Nazi actions but simply reframes moral statements as non-factual overlooks a crucial problem: the distinction between what feels wrong and what is wrong. 
If moral judgments were merely subjective, the moral condemnation of the Holocaust would hold no more objective weight than a personal distaste for a particular food. This relativism leads to moral paralysis, where there is no justifiable basis for saying, "Genocide is evil," as anything more than a personal preference. Yet, we recoil at this conclusion because we intuitively sense that some actions—like genocide—are universally wrong. This intuition points to the existence of objective moral values, which transcend subjective or cultural differences.
The burden of proof is actually on the subjective ethicist to make an account of why the Nazi party would be wrong to carry out their actions if they believed that the world should have any morality other than the one they espoused. 
Moral Realism and Circular Reasoning
You accuse my argument of circular reasoning when I assert that "there are universal rules about how we treat humans that capture this symmetry of fairness." However, this is not circular reasoning, but rather an attempt to ground moral objectivity in the nature of human interactions and fairness. Moral truths, much like mathematical axioms, are self-evident upon reflection. For example, the principle of fairness—that all human beings deserve equal moral consideration—is an intuitive moral fact that applies regardless of subjective beliefs. It is not assumed but rather recognized as objectively valid upon rational consideration.
The Argument From Biology
You claim that my argument from human biology and the shared nature of human experiences does not establish objective morality because it rests on the unproven assumption that human well-being is inherently good. However, this misinterprets the argument. The grounding of objective morality in human biology does not claim that well-being is arbitrarily good; it shows that moral facts emerge from the nature of human beings as rational agents capable of flourishing or suffering.
Just as we derive objective medical truths about health based on human biology, we can derive objective moral truths based on the conditions necessary for human flourishing. The fact that human beings universally seek to avoid suffering and pursue well-being suggests that there are objectively better or worse ways to structure society, treat others, and fulfill our moral duties. The existence of moral disagreements does not undermine this argument any more than scientific disagreements undermine the objectivity of scientific truths.
Cultural Variation and Objective Morality
In response to my points about cultural contradictions, you question how I can know that societies are "moving in the right direction" when moral beliefs evolve. The fact that societies once accepted practices such as slavery or marital rape does not prove that morality is subjective, only that human understanding of objective moral truths can be fallible and evolve over time. Moral progress does not require the invention of new moral truths, but rather the recognition and application of moral facts that were always objectively true.
For example, the abolition of slavery was not the creation of a new moral standard but the recognition of the intrinsic wrongness of treating human beings as property. Similarly, the criminalization of marital rape reflects the recognition of bodily autonomy as a moral principle that was always true but not always acknowledged. This evolution supports the claim that moral truths exist independently of cultural beliefs and that societies can move closer to understanding and applying these truths.
Hume's Guillotine and Deriving Ought from Is
Your appeal to Hume's Guillotine—the argument that one cannot derive an "ought" from an "is"—misses a key point about moral objectivity. While it is true that a purely descriptive fact cannot entail a moral obligation, this does not mean that moral facts do not exist. Moral realists argue that there are normative facts built into the very nature of human existence. Just as certain facts about physical health entail specific medical prescriptions, certain facts about human flourishing entail moral obligations.
For example, if we accept the objective fact that human beings require food, shelter, and social cooperation to thrive, we can derive moral obligations to ensure these conditions are met. The argument is not circular because it does not assume the truth of moral claims but derives them from the factual nature of human beings as rational, social creatures.
Moral Realism and Logical Consistency
You conclude by arguing that moral realism is filled with logical fallacies, but this critique misunderstands the nature of moral reasoning. While moral truths are not demonstrable in the same way as empirical or mathematical truths, they are nonetheless objective. Just as mathematical truths rely on certain self-evident axioms, moral truths rely on the self-evident recognition of human dignity, fairness, and well-being. The fact that moral claims are not empirically provable does not mean they are subjective; rather, they belong to a different category of truth—normative rather than descriptive.
Conclusion
Moral anti-realism leads to untenable conclusions, such as the inability to objectively condemn atrocities like genocide or slavery. By contrast, moral realism provides a robust framework for understanding why certain actions are universally right or wrong, based on the objective facts of human nature, fairness, and flourishing. Moral disagreements do not undermine the existence of objective morality; rather, they reflect the challenge of discovering and applying moral truths in a complex world.