Moral skepticism is the view that moral judgments are not objectively true or false, but rather are subjective or meaningless.

Moral nihilism is the view that there is no such thing as objective morality, and that all moral values are subjective and relative.

David Hume is most closely associated with moral skepticism, particularly through his famous argument that moral judgments cannot be derived from reason alone.

Friedrich Nietzsche is most closely associated with moral nihilism, particularly through his famous declaration that 'God is dead' and his subsequent critique of traditional morality.

The main objection to moral skepticism is that it is self-refuting. If moral skepticism is true, then the claim that moral skepticism is true is also meaningless. This leads to a logical contradiction.

The main objection to moral nihilism is that it undermines the possibility of moral progress. If there is no such thing as objective morality, then there is no way to say that one moral code is better than another. This makes it difficult to see how moral progress can be possible.

The argument from common sense is a common argument against moral skepticism. It argues that the fact that most people believe in objective morality is evidence that objective morality exists.

The argument from moral progress is a common argument against moral nihilism. It argues that the fact that moral progress has been made over time is evidence that objective morality exists.

Moral skepticism is the view that there is no such thing as objective morality, while moral relativism is the view that moral values are subjective and relative. Moral skepticism is a more radical view than moral relativism, as it denies the existence of objective morality altogether.

Moral nihilism is the view that there is no such thing as objective morality, while amoralism is the view that there is no such thing as morality at all. Moral nihilism is a more moderate view than amoralism, as it allows for the possibility of subjective morality.

David Hume is an example of a moral skeptic. He argued that moral judgments cannot be derived from reason alone, and that they are therefore subjective and relative.

Friedrich Nietzsche is an example of a moral nihilist. He argued that there is no such thing as objective morality, and that all moral values are subjective and relative.

The argument from common sense is an example of an argument against moral skepticism. It argues that the fact that most people believe in objective morality is evidence that objective morality exists.

The argument from moral progress is an example of an argument against moral nihilism. It argues that the fact that moral progress has been made over time is evidence that objective morality exists.