How did skepticism question whether moral values have an objective basis?

Skepticism questions the objective basis of moral values by challenging the existence of universal, culture-neutral standards and the possibility of accessing moral facts. Philosophers have historically approached this through several key arguments:12

• Subjectivity and Sentiment: Drawing on the work of David Hume, many skeptics argue that moral beliefs are rooted in human emotion or "sentiment" rather than reason. This perspective, often associated with emotivism, suggests that moral statements serve to express personal feelings or influence others rather than to record objective facts.13
• Cultural Relativism: Skeptics observe that moral codes vary significantly across societies. They argue that because morality is a social product, there is no culture-neutral standard to determine which society’s view is correct, rendering moral judgments relative to specific social arrangements.1
• Metaphysical and Epistemological Challenges: Critics of moral realism point out that it is difficult to explain how humans could access a realm of "moral facts" that are distinct from natural facts. Furthermore, some theorists, such as J.L. Mackie, have argued that moral properties are inherently "queer" compared to natural ones, leading them to deny their existence entirely.3
• Perspectivism: Influenced by Friedrich Nietzsche, some thinkers argue that there are no objective moral facts, only different perspectives or interpretations of phenomena that give rise to various moral codes.1