Intro to Meta Ethics
Meta-ethics is the field in philosophy which attempts to answer the question of what goodness is.
This opens up a domain of philosophical investigation ‘above’ normative ethics (hence ‘meta-ethics’) in which competing meta-ethical theories argue for what they claim goodness actually is.
Normative ethics are ethical theories which attempt to devise a system which enables us to determine which actions are good and which are bad. Natural Law, Situation ethics, Virtue ethics, Utilitarianism and Kanian ethics are all normative theories.
Normative ethical theories all have a Meta-ethical core. For example, some forms of utilitarianism claim that goodness = pleasure/happiness. That is a meta-ethical view about what goodness is and forms Utilitarianism’s meta-ethical core. Once that is established, Utilitarianism can go on to formulate the details of a system that enables us determine which actions are good and which bad. For example, in the case of Act Utilitarianism, that would include the hedonic calculus.
Normative theories typically require that goodness at least exists, though they argue over what it actually is. However, some meta-ethical theories (anti-realist theories) claim that goodness does not actually exist.
There are two main aspects to answering the question of what goodness is: metaphysical and linguistic.
Metaphysical: What is the nature of goodness? There are two opposing views on this:
Moral Realism: The view that moral properties (like goodness/badness) exist in reality.
Moral anti-realism: The view that moral properties (like goodness/badness) do not exist in reality.
Linguistic: What is the meaning of ethical language? There are two opposing views on this:
Cognitivism – ethical language expresses beliefs about reality which can therefore be true or false.
Non-cognitivism – ethical language expresses some non-cognition like an emotion, does not attempt to describe reality and therefore cannot be true or false.
The outcome of meta-ethical debate has the utmost importance for normative ethics. If anti-realism is true and there is no such thing as objective goodness/badness, then it seems difficult to construct a normative theory. If moral-realism is true and goodness does exist in reality, then what exactly goodness is will limit the normative theories which are valid to those based on that correct view of goodness.
Divine Command Theory
This is the view that God is the origin and regulator of morality. God’s act of commanding something as good or bad is what makes it good or bad. E.g. 10 commandments & Aquinas’ notion of the ‘divine law’ – God’s revelation to humans.
Abraham and Isaac – God commanded Abraham to kill his son Isaac to prove his faith and loyalty. Abraham was about to kill his son when God sent an angel to stop him, saying he had proved his faith and they sacrificed a ram instead. If God commands something, even if it’s killing your child – it is good.
God’s command makes something right or wrong in an objective sense. Objective means mind-independent. If something is objectively true then it is a matter of fact, not of opinion. It cannot be relativised. Since right/wrong is a matter of God’s command, becoming good or achieving moral goodness is simply a matter of following God’s commands. Christians believe that God exists and therefore the fundamental nature of reality includes divinity. Since morality is what God commands, morality therefore has a meta-physical foundation in reality.
If there were a command superior to God’s command then God would be inferior to that thing. However, God is all-powerful and cannot be inferior to or subject to anything else. If goodness were not a matter of God’s command, then God would be unable to change what is good/bad or to make something good/bad. In that case, there would be something God lacks the power to do – which would make him not omnipotent. Omnipotent power has to include power over morality.
The Euthyphro dilemma
In Philosophy, a Dilemma is when there are two ways something could be, each way leading to a problem. The two options are called horns.
The Euthyphro dilemma in its modern form asks: is what God commands good because it is good (1st horn), or is it good because God commands it? (2nd horn).
God’s Omnibenevolence is the idea that God is perfectly good. However, the Euthyphro dilemma shows that there are two ways we could understand God being perfectly good.
The first horn Is it that what God commands is intrinsically good independently of God. This suggests that God is perfectly good because he perfectly follows an intrinsically good moral standard that is separate from God. The problem this leads to an apparent conflict with omnipotence, since this external moral standard is beyond God’s power to control.
The second horn is that it is God’s act of commanding something that makes it good. This suggests that God is perfectly good because perfectly good is whatever God commands it to be. This leads to the arbitrariness problem, that God could change his mind about what is good.
Divine command theorists attempt to either defend the second horn from the arbitrariness problem or reject the Euthyphro dilemma as a false dilemma.
The first horn leads to a conflict with God’s omnipotence
If we take the other horn and suppose that when God commands something to be right or wrong, he is really just informing us about what is intrinsically good. This seems to require that goodness is a standard which is independent of God and has some objective status of its own. In that case, God would be just as judged by that standard as we are, and God would not have the power to change it, otherwise what’s good would then ultimately reduce to his command. The idea that God cannot do something or is himself held to a standard higher than himself seems to conflict with his omnipotence.
Swinburne defends taking the second horn. He argues that some moral truths are necessary. In that case, they must be true, so it would be logically impossible for God to change it. Most theologians agree that omnipotence involves the power to do any logically possible thing, not logically impossible things. An intrinsic moral standard external to God which involves necessary moral truths cannot possibly be changed. It is logically impossible to make necessary truths false. In that case, that God cannot control or change morality is not actually undermining of God’s omnipotence.
The second horn (Divine command theory) leads to the arbitrariness problem
Those who accept the second horn are called divine command theorists. They face the arbitrariness problem. This is the problem that if what is good is only good because God commanded it to be so, then it seems that God could change his mind tomorrow and command that murder is good, which would mean that it thereby became good on the divine command theory view. Furthermore, it seems that God’s choice of murder to be what he commanded as wrong must have been random and arbitrary. On divine command theory, there was nothing wrong about murder until God commanded it wrong, but that means there was nothing that could have prompted God’s choice for it to be wrong. Once it is admitted that the only thing which confers rightness or wrongness is God’s command, then it seems that absent his command, nothing has any rightness or wrongness and his choice of what to command must therefore be completely random.
This also seems to bring God’s reasonableness into question. If God is acting arbitrarily then he cannot be acting based on reasons.
The response that the Euthyphro is a false dilemma. Medieval theologians (Augustine, Aquinas and Anselm) attempted to solve the Euthyphro dilemma by suggesting there is a third option, making it a false dilemma.
A false dilemma is one which poses two options when really there are others. Arguably there is a third option than the two proposed by the Euthyphro dilemma. This third option is that what God commands is good because it accords with God’s omnibenevolent nature.
K. Rogers explains this move: “God neither conforms to nor invents the moral order. Rather His very nature is the standard for value.”
The goodness of God’s commands does not depend on God’s arbitrary choice, nor on some intrinsic standard of goodness external to God, but on God’s perfectly loving nature which is intrinsic to God. The claim that God is omnibenevolent in that God is the standard and source of moral goodness is therefore defended against the Euthyphro dilemma.
This solves the arbitrariness problem because God’s choices of what to command are not arbitrary but a consequence of his perfect omnibenevolent nature. Essentially, God won’t and can’t change his mind tomorrow about what is good because his commands are a result of his perfect unchanging omnibenevolent nature.
This also solves the other horn of the Euthyphro dilemma; that God commands what is good because it is good. For Adams, what makes God’s commands good is their accordance with God’s omnibenevolent nature. This avoids the threat to omnipotence made by an external standard to which God must conform. The standard is God himself.
God does change his mind. There seems to be evidence in the bible of God changing his mind about the moral code we need to live by. Jesus, in the sermon on the mount, changed some of the old testament laws – e.g. ‘eye for an eye’ into ‘turn the other cheek’.
Christians tend to respond to this by claiming that this was not God changing his mind, it was simply God changing the covenant he had with humans from the restrictive one he had only with the Jewish tribe to the expanded covenant enabled by Jesus’ sacrifice which became open to all people. It was a change in covenant – not in God’s mind.
The issue of the grounding of God’s goodness. Attempts to solve the Euthyphro dilemma by appealing to God’s intrinsic loving nature are vulnerable to the issue of accounting for why God’s nature is good. The Euthyphro dilemma is trying to get to the bottom of why/what it is that makes God’s commands good. If the answer is God’s nature, then the question simply becomes why is God’s nature good or what is it that makes God’s nature good? This move by philosophers like Aquinas and Adams arguably merely kicks the can down the road.
The Pluralism objection to divine command theory
There are multiple religions and many more have existed in the past and there are potentially an infinite number that we could invent. Even if we accepted divine command theory, how could we possibly know which God is real, and so which divine commands are the right ones? As Hume said about miracles, the fact that different religions all have miracle stories in them mean that their claims cancel each other out. The same could be said of different divine commands in different religions.
The pluralism objection can be developed by pointing to the possibility of an infinite number of interpretations of the Bible. It looks like you could potentially justify anything since the Bible is infinitely interpretable – or at least interpretable to a worrying degree. So the pluralism of divine commands issue applies even within Christianity – not just between Christianity and other religions.
Response to the Pluralism objection can involve attempting to prove that a particular religion like Christianity is true, such as N. T. Wright’s arguments for the historicity resurrection for example.
The success of such attempts are debatable, however. Even if they succeed, they still have the issue of inter-denominational dispute over divine commands.
The other approach to dealing with the pluralism objection is simply to accept pluralism – the view that all religions are just different cultural manifestations of the divine, therefore all are true. This means they are not compatible. This view is held by William James and Hick. James thinks that mystical religious experience occurring in all religions shows that they are all true. Hick argues that the different religions of the world are like blind men each touching a different part of an elephant. They each report they are feeling something different, yet that is because they are just too blind to see how they are really part of the same thing. Hick claims that the main command from divinity in all religions is that we should be righteous and loving. So, that’s the command we should follow.
It’s hard to see how all religions could be true given their incompatible truth claims, however.
The issue of immoral commands
Divine command theory has the issue that the Bible seems full of commands which are immoral. For example:
“I do not permit a woman to teach or to have authority over a man; she must be quiet. For Adam was formed first, then Eve. And Adam was not the one who was deceived, it was the woman … But women will be saved through childbearing”. 1 Timothy 2:12
“If a man lies with a man as he does with a woman, both have committed an abomination. They shall surely be put to death, their blood is upon them”. Leviticus 20:13.
The people of Samaria must bear their guilt, because they have rebelled against their God. They will fall by the sword; their little ones will be dashed to the ground, their pregnant women ripped open.” Hosea 13:16
Slaves, obey your earthly masters with respect and fear, and with sincerity of heart, just as you would obey Christ. Ephesians 6:5.
Anyone who beats their male or female slave with a rod must be punished if the slave dies as a direct result, but they are not to be punished if the slave recovers after a day or two, since the slave is their property. Exodus 21:20-21
Richard Dawkins sums this up: “The God of the Old Testament is arguably the most unpleasant character in all fiction … [a] bloodthirsty ethnic cleanser … misogynistic, homophobic, racist, infanticidal, genocidal”
Liberal Christians solve this issue through a subjective theory of inspiration – accepting that the Bible is the product of the human mind, not the perfect word of God.
However, that means the Bible cannot be used as a list of divine commands and so cannot help the divine command theorist.
Ethical Naturalism
This is the view that goodness is something real in the natural world – typically a natural property. The natural world is the physical world. A natural property is a trait or feature that a natural thing has. For example, temperature would be a natural property.
Bentham’s Utilitarian naturalism
Bentham’s Utilitarianism claims that goodness = pleasure. Pleasure is a natural property (at least if you don’t believe in a non-natural soul) of natural creatures. Meta-ethically, Utilitarianism is therefore a form of naturalism, moral realism and cognitivism.
“Nature has placed us under the governance of two sovereign masters, pain and pleasure. It is for them alone to point out what we ought to do, as well as to determine what we shall do … a man may pretend to abjure their empire: but in reality he will remain subject to it all the while”.
Bentham’s argument is that it is our human nature to seek pleasure and avoid pain, so that’s all there is for morality to be about. We just are the kind of thing which cannot help but find pleasure good and pain bad. Bentham claims we could try to pretend otherwise but cannot escape this nature. As this is a fact of our nature, it is therefore a fact that goodness = pleasure.
The linguistic claims of naturalism are straightforwardly that ethical language is cognitive as it functions no differently to expression of any other type of belief about reality. To describe the color of the table, I say ‘the table is brown’. This is a sentence expressing a belief about reality. The ethical language ‘stealing from that bank is good’ is no different for the naturalist. It is a sentence and a proposition about reality which will be either true or false depending on the sense in which that particular action of stealing involves whatever natural property the naturalist claims to be good.
Hume’s is-ought gap
Hume’s is-ought gap (also called Hume’s law) criticises naturalism. Hume said philosophers talk about the way things are and then jump with no apparent justification to a claim about the way things ought to be. Put another way, an evaluative conclusion cannot follow from factual premises. An evaluative conclusion or evaluative premise is one which contains a value judgement.
One way of appreciating Hume’s argument is seeing that, for any moral proposition, you cannot give a factual justification for its truth. Take the example of “it is wrong to kill people” and try to figure out what the factual justification is for it. Why is it factually wrong to kill people?
You could try to point out facts about killing people, such as that it hurts or harms people or violates their preferences. It is indeed a fact killing people can involve such things. However, why is it a fact that it’s wrong to harm people? Why is it a fact that it’s wrong to violate people’s preferences?
Whatever answer someone presents as a fact (is-statement) from which they have inferred their value judgement (ought-statements), it seems you can always question what their reason is for that inference.
Any move from a factual is-statement such as “killing people causes suffering” to: “therefore, killing people is wrong” simply assumes that causing suffering is wrong. It looks like we cannot infer values from facts.
The problem is, how we can possibly reach evaluative conclusions from purely factual premises? It looks like we simply have to baselessly assume that a particular fact entails a particular value.
P1. Killing people causes suffering.
C1. Killing people is wrong.
The inference from P1 to C1 is only valid if we assume the following hidden evaluative premise:
P2. Causing suffering is wrong.
Any attempt to reason from facts to values will simply presuppose a hidden evaluative premise which cannot itself be derived from facts. So, we cannot get an ought (evaluative premise or conclusion) from an is (factual premise). Here’s another example:
P1. Allowing stealing will cause society to fall apart.
C1. Stealing is wrong.
This assumes the hidden premise:
P2. Causing society to fall apart is wrong.
Regarding Bentham & Mill, they point out that our nature finds pleasure good. Yet, Hume would point out that this only shows that our nature finds pleasure good, not that pleasure is good and that we therefore ought to maximise pleasure.
Hume concludes that you could be aware of all the facts about a situation, yet if you then pass a moral judgement, that cannot have come from ‘the understanding’ nor be ‘the work of judgement’ but instead comes from ‘the heart’ and is ‘not a speculative proposition’ but is an ‘active feeling or sentiment’. This looks like an argument against realism but also against cognitivism and for non-cognitivism, specifically emotivism.
Moore’s naturalistic fallacy
A fallacy is a logical error resulting from an assumption or a mistake in reasoning. There are different fallacies covering the different types of logical errors. Moore was influenced Hume’s is-ought gap argument and developed it into the form of a fallacy called the naturalistic fallacy. Applied to naturalism, it takes this form:
It is a fallacy to assume that something being natural means that it is good.
Naturalists seem to make that assumption. For example, Bentham argues that because it is human nature to for pleasure to be our ultimate desire, then pleasure is good. Yet, this commits the naturalistic fallacy. One can’t simply assume that something being natural means that it is good. The fact that it is natural for us to find pleasure good only shows that it’s natural for us to find pleasure good. It doesn’t mean pleasure is good.
Many philosophers have noted that the naturalistic fallacy is poorly named, since Moore also intended his naturalistic fallacy to attack other forms of non-naturalism. This includes many forms of religious Meta-ethics. For example, divine command theory claims that goodness = being commanded by God. Attempting to reduce goodness to God or Gods commands forms a non-naturalist theory since God and God’s commands are not natural things or properties. What makes God’s commands good? It’s difficult for a divine command theorist to answer that except through merely assuming that it is.
Moore’s real target is the attempt to reduce or define goodness in terms of anything else – even in terms of something non-natural. Whichever way goodness is proposed to be defined through reduction to something else, whether natural things like pleasure or non-natural things like the command of a God, it seems impossible to actually have a reason for doing so. All reductive accounts of goodness therefore rest on baseless assumption and so commit the naturalistic fallacy.
Response to Hume and Moore: arguments for Naturalism are inductive
Hume’s is-ought gap and Moore’s naturalistic fallacy can both be responded to by taking arguments for Naturalism as inductive rather than deductive.
Patricia Churchland argued for interpreting Hume as only targeting deductive reasoning from is to ought, such that that factual statements cannot entail moral statements. However, Hume doesn’t seem to say it’s impossible to reason from is to ought, just that philosophers have failed to do so thus far. Churchland proposes that Hume’s argument leaves it open for inductive reasoning to do that job. This approach can respond to Moore’s naturalistic fallacy too.
We could take Bentham and Mill’s arguments for utilitarian naturalism as inductive. Their claim is not that our nature finding pleasure good proves that pleasure is good, but that our nature finding pleasure good is evidence for pleasure being good. Natural premises do not entail evaluative conclusions, but they could support evaluative conclusions.
Hume and Moore’s issue is, how do we get from is (fact) to ought (value).
How do we get from:
P1. Pleasure is what we naturally desire. (is/fact)
To:
C1. Pleasure is good and so we ought to maximise pleasure (ought/value
The difficulty is that P1 is simply a different statement to C1. There doesn’t seem to be any reason to think that P1 proves C1. All we have is baseless assumption that something being natural could prove that it is good. So, this argument cannot work as a deductive proof. There is no reason to think that P1 being true means that C1 must be true. However, if we take Bentham & Mill’s arguments as inductive, then P1 is only evidence which supports C1.
The fact that all beings which can experience pleasure adopt it as their final end arguably is evidence that pleasure is good. The idea behind this proposal seems to be that it is unlikely to be a coincidence that all the diverse forms of action and behaviour ultimately reduce to the same goal of gaining happiness and avoiding suffering. It looks like the fact of psychological hedonism gives us reason to think that goodness = happiness.
Mill especially seems to accept that he is making an inductive argument when he admits that his proof of Utilitarianism is the ‘only proof’ possible, suggesting he accepts that it is not absolute deductive proof but only inductive evidence.
This approach could be used to respond to Moore’s naturalistic fallacy too, since it gives us an inductive reason to think that something being natural means that it is good in that in the case of pleasure, it being our sole and ultimate desire is evidence that it is good.
The claim that goodness = pleasure is not based on mere baseless assumption, then. It is based on evidence.
However, consider that we have strong evidence that human nature finding pleasure good is the result of evolution, in order to guide animals to evolutionary goals. So, we are not justified in regarding our nature finding pleasure good as evidence for pleasure actually being good since we have stronger evidence for it being the result of something else (evolution).
The open question argument
Moore argued that if naturalism were true, the result would be illogical. Take any naturalist claim about what goodness is, such as that goodness = pleasure.
IF: goodness = pleasure
THEN: (goodness = pleasure) = (pleasure = pleasure)
BUT: goodness = pleasure is informative, telling us about the world
YET: pleasure = pleasure is not informative (tautology), telling us nothing.
An informative statement cannot be equal in meaning to an uninformative tautological statement. So, goodness cannot = pleasure, or any other natural property. Therefore, naturalism is false.
A question is closed if it shows ignorance of the meanings of the terms involved to ask. A question is open if it does not display ignorance of those meanings to ask it. Since ‘Goodness = X natural property’ for a naturalist would be synthetic, one could be acquainted with the subject (goodness) but not the predicate (X natural property) and therefore would not necessarily be displaying ignorance of the terms involved to ask the question. Therefore, it will always be an open question whether goodness really is X natural property as we can always meaningfully and intelligibly ask the question ‘is goodness really X natural property?’
Mackie’s response to the open question argument: arguably Moore can at most prove that our linguistic concepts of goodness and pleasure are distinct concepts that cannot be identical. That doesn’t tell us anything about the actual metaphysical status of goodness in reality. Mackie made this kind of argument, claiming that in Moore’s time philosophers were too optimistic in thinking that linguistic analysis could tell us metaphysical truths.
“There are questions of factual rather than conceptual analysis: the problem of what goodness is cannot be settled conclusively or exhaustively by finding out what the word ‘good’ means, or what it is conventionally used to say or to do. Recent philosophy, biased as it has been towards various kinds of linguistic inquiry, has tended to doubt this.” – Mackie.
Moore’s Intuitionism
The open question argument showed that goodness cannot be identical to any natural property. We cannot say that goodness is equivalent to any natural thing. This means goodness cannot be defined. We can define water as being equal to H2O but cannot say what goodness equals. The naturalistic fallacy shows that goodness cannot be identical to anything at all, natural or non-natural.
Moore concluded that we can’t define goodness. We can’t say what goodness is because it is only itself – it is sui generis (unique). It is like the color yellow – you can’t describe or define yellow, you just experience it and can only point to yellow things. Moore argues the same is true for goodness. Therefore, goodness can’t be a naturalistic thing as naturalistic things can all be defined. So, we experience goodness, which Moore clams is due to a faculty of intuition.
Moore holds that when we observe or reflect on a moral situation, such as someone stealing, our intuition gives us the proposition ‘stealing is wrong’, depending on the consequences. This isn’t reducing morality to some subjective feeling however. Just as all humans have no choice but to perceive the color yellow when looking at a yellow thing, Moore thinks humans have no choice but to apprehend the truth or falsity of a moral proposition when observing or reflecting on the relevant moral situation. He thinks this occurs because we apprehend ‘non-natural properties’. Intuitionism is cognitivist as Moore thinks that ethical language expresses a belief about the non-natural reality, which is based on an intuition.
Moore is criticised for having an indulgent metaphysics of non-natural properties existing in a supersensible realm being somehow apprehended by a mysterious faculty of intuition. How could he possibly prove any of this?
Moore responds by making an analogy between his non-natural notion of ‘goodness’ and numbers, saying that neither ‘exist’ but do have ‘being’ in some way. The idea here is that numbers do not seem to be natural objects like trees or atoms. However, numbers do seem to have something to do with reality. Therefore, there must be a non-natural aspect or level to reality where numbers are and Moore says that’s where goodness is also. Moore says there is no supersensible reality. By ‘intuitive’ he only meant not inferred from other kinds of knowledge like logical or natural truths.
Moral disagreement. Not everyone has the same intuition about what is ethically good or bad. How can Moore explain moral disagreement if everyone has intuitive access to objectively true moral propositions?
Moore firstly argued that people often fail to be as clear as possible in their ethical propositions, which he thinks explains much of the moral disagreement.
Moore secondly argued that intuitions can be made at different levels of abstraction and furthermore Moore was a consequentialist, which means that there could be different intuitions about the same action in different situations. So the process of figuring out ethical truth required fitting your intuited moral propositions together into a coherent whole. If we could come together and discuss the situations our different intuitions apply to, he thinks we would agree.
Pritchard, an intuitionist, responds that moral disagreement occurs because some are less morally developed than others.
But consider The Pope, the Dali lama, and Peter singer. All are very morally developed people, yet all differ radically in their conception of ethics.
Mackie has the view that people’s intuitions about ethics do express cognitive truth claims, but that their ethical views are only true or false relative to an individual or culture, so true ‘for them’. Mackie argues that relativism is a better explanation of moral disagreement between different cultures than Intuitionism. People have moral intuitions, but they come from their culture or individual mind, they are not perceptions of a non-natural reality. Freud’s views on the conscience would also support this, since he thought our moral views were conditioned into our super-ego by our society.
There are a set of core moral principles similar in all societies however, such as prohibitions on stealing and murder. This could suggest there is some absolutist moral truth that humans are somehow apprehending.
Arguably societies have similar views on murder and stealing because a society which allowed such actions would fall apart and cease to exist. So societies have that core similarity because of practical necessity, not because of absolutist objective moral truths.
Emotivism
Ayer agreed with G.E Moore’s naturalistic fallacy argument, that ‘goodness’ could not be identical with any natural property. However, Ayer disregarded Moore’s ‘non-natural’ properties solution as unverifiable. Ayer thinks we are therefore left with the position that there are neither natural nor non-natural moral properties in reality, so anti-realism is true. Ayer’s anti-realism relies on the success of Moore’s arguments against naturalism therefore, however, as his own theory only specifically targets intuitionism.
Ayer accepted the fact-value distinction that Hume’s is-ought gap implied. Ayer also thought the connection between moral judgement and motivation and the connection between motivation and feeling, made it most plausible that emotions were the best candidate for explaining the psychological function of ethical language and its unverifiability. Unlike subjectivism which claims we are describing or reporting our feelings, Ayer thinks we are expressing them when using ethical language.
Boo/hurrah theory. Ayer concluded ethical language was meaningless according to his verificationist theory of meaning, since it can’t be empirically verified nor is it analytically true. Ayer proposed that rather than attempting to describe reality, ethical language really expresses emotion. Saying ‘X is good’ is really akin to hitting ur toe on a chair and saying ‘oww’. The meaning of ‘oww’ is that it expresses – it connects to – the part of your mind that feels pain. That feeling of pain is not a cognitive belief that could be true or false. It’s the same with ethical language says Ayer – it connects to and expresses non-cognitive emotions, not cognitive beliefs. So ‘X is wrong’ is really ‘boo to X’, or ‘X is good’ is really ‘hurrah to X’.
Ayer’s claim is that there is nothing more to ethics than expressing emotion. It follows that there is no objective truth nor falsity in ethics. Different people are not good or bad, they just have different emotional associations. Hitler had a particular emotional association towards Jews. There’s nothing more that can be said, no way to say Hitler was ‘really wrong’, just that one might have a different emotional reaction than him.
Some bring up this sort of point as a criticism against emotivism since if this was believed by everyone then the world might descend into anarchy and chaos if there are no objective ethical principles. This criticism in a way misses the point of meta-ethics however. Meta-ethics is just trying to determine what rightness and wrongness are. We may not like the result of a particular meta-ethical theory, it may indeed lead to the destruction of the world. But that doesn’t mean it’s incorrect. The science behind nuclear bombs may well end up destroying the world, but that doesn’t mean it’s incorrect. If ethics really is mere expression of emotion, then we can’t disprove that merely by pointing out what would be the consequence of everyone believing that as an argument against its truth.