Argument from absolutism

1. if moral claims are objectively true, then moral rules are absolute
2. no moral rules are absolute
3. therefore, moral claims are not objectively true

Argument against objective truths

1. there are no objective truths
2. therefore, there are no objective moral truths

Argument from equal rights

1. if everyone has an equal right to an opinion, then all opinions are equally plausible
2. everyone has an equal right to his or her moral opinions
3. therefore, all moral opinions are equally plausible
4. if all moral opinions are equally plausible, then ethical objectivism is false
5. therefore, ethical objectivism is false

Argument from dogmatism

1. if there are objective moral standards, then this makes dogmatism acceptable
2. dogmatism is unacceptable
3. therefore, there are no objective moral standards

Argument from tolerance

1. tolerance is valuable only if the moral values of different people are equally plausible
2. if ethical objectivism is true, then the moral views of different people are not equally plausible
3. therefore, if ethical objectivism is true, then tolerance is not valuable

Argument from cultural variation

1. if ethical objectivism is true, then all moral standards apply universally- to everyone, in every society
2. some moral standards do not apply universally, but only in certain cultural or social contexts and not in others
3. therefore, ethical objectivism is false

Argument from disagreement

1. if well-informed, open-minded, rational people persistently disagree about some claim, then that claim cannot be objectively true
2. well-informed, open-minded, rational people persistently disagree about all moral claims
3. therefore, no moral claim can be objectively true

Argument from Atheism

1. morality can be objective only if God exists
2. God does not exist
3. therefore, morality cannot be objective

Argument from categorical reasons

1. if there are objective moral duties, then there are categorical reasons to obey them
2. there are no categorical reasons
3. therefore, there are no objective moral duties

Motivational argument

1. moral judgments are able, all by themselves, to motivate those who make them
2. beliefs are never able, all by themselves, to motivate those who hold them
3. therefore, moral judgements are not beliefs
4. if moral judgments are not beliefs, then they can’t be true
5. therefore, moral judgments can’t be true

Argument from the Scientific Test of Reality

1. if science cannot verify the existence of X, then the best evidence tells us that X does not exist
2. science cannot verify the existence of objective moral values
3. therefore, the best evidence tells us that objective moral values do not exist