Is all morality subjective?

If you were asked whether it is wrong to torture an innocent child, your immediate reaction would likely be one of absolute, non-negotiable horror. Yet, if morality is merely a byproduct of human evolution or cultural conditioning, that horror is no more objective than a dislike of broccoli. This is the central tension of moral philosophy: we live our lives as if moral facts are as real as gravity, yet we struggle to find them in the physical world. To answer whether all morality is subjective, we must distinguish between *where our moral beliefs come from* and *whether those beliefs refer to objective truths*. ## The Case for Moral Realism Many philosophers argue that morality is objective, a view known as [Moral Realism](https://plato.stanford.edu/entries/moral-realism/). Realists argue that certain moral claims are true regardless of what any individual or culture believes. Just as the earth was round before humans discovered it, certain actions are wrong regardless of our opinions. The prominent philosopher G.E. Moore argued in his landmark work, *Principia Ethica*, that "good" is a simple, indefinable property that we perceive through moral intuition. Realists point out that when we debate moral issues, such as human rights or justice, we are not merely expressing personal tastes. We are behaving as if there is a correct answer to be found. If morality were entirely subjective, a statement like "slavery is wrong" would merely mean "I dislike slavery," making genuine moral disagreement impossible. ## The Case for Moral Anti-Realism Conversely, defenders of [Moral Anti-Realism](https://plato.stanford.edu/entries/moral-anti-realism/) argue that morality is fundamentally subjective. A major proponent of this view was the Scottish Enlightenment philosopher David Hume, who famously argued in *A Treatise of Human Nature* that we cannot derive an "ought" from an "is." > "Take any action allowed to be vicious: Wilful murder, for instance. Examine it in all lights, and see if you can find that matter of fact, or real existence, which you call vice... The vice entirely escapes you, as long as you consider the object. You never can find it, till you turn your reflection into your own breast, and find a sentiment of disapprobation, which arises in you, towards this action." In the twentieth century, J.L. Mackie championed "Error Theory" in his book *Ethics: Inventing Right and Wrong*. Mackie argued that while our moral language *claims* to be objective, all such claims are actually false because objective moral values simply do not exist in the universe. Ultimately, while our *perceptions* of morality are undoubtedly shaped by subjective factors like culture and biology, the question of whether a fundamental moral reality exists remains one of the most vital debates in philosophy. ## Follow-up questions 1. If evolutionary biology can fully explain why we feel certain actions are wrong, does that completely undermine the argument for objective moral truths? 2. How can moral realists explain the vast and persistent disagreement about moral issues across different cultures and historical eras? 3. If we accept that morality is entirely subjective, on what grounds can we legitimately judge or interfere with the practices of other cultures?

If every moral code is merely a local custom, on what grounds can we condemn the atrocities of another society? If we accept that morality is entirely subjective, any attempt to interfere with another culture’s practices looks less like a defense of justice and more like cultural imperialism. Yet, humanity has repeatedly refused to remain silent in the face of foreign cruelty. To resolve this tension, contemporary thinkers have moved beyond traditional moral realism to find legitimate grounds for cross-cultural critique. ## The Coherence Test: Internal Critique One of the most powerful tools for judging another culture without relying on objective moral facts is **internal critique**. This approach does not evaluate a society by an external, universal standard. Instead, it asks whether a culture’s practices are consistent with its own stated values. The philosopher [Martha Nussbaum](https://en.wikipedia.org/wiki/Martha_Nussbaum), known for her development of the [capabilities approach](https://plato.stanford.edu/entries/capability-approach/), argues that we can critique cultures by looking at the internal contradictions of their practices. For example, if a society explicitly values the flourishing and agency of all its citizens, but simultaneously denies education to women, an outsider can point out this logical inconsistency. We are not imposing our subjective values on them; we are holding them accountable to *their* subjective values. ## The Overlapping Consensus of Human Biology Another avenue for critique comes from grounding our subjective moralities in shared biology rather than metaphysical facts. While moral truths may not exist in the cosmos, human beings share a highly conserved evolutionary blueprint. In *The Moral Landscape*, neuroscientist and philosopher Sam Harris argues that the moment we define "good" in relation to the well-being of conscious creatures, morality becomes a matter of objective analysis, even if the starting definition is subjective. > "If we define 'goodness' as that which supports human flourishing, then questions about right and wrong have objectively true and false answers." Because all humans share basic neurological requirements to avoid extreme suffering, we can critique cultures that systematically inflict trauma—such as through institutionalized torture or starvation—not because they violated a cosmic law, but because they are demonstrably failing to optimize human well-being. ## Pragmatism and the "Aesthetic" Clash of Wills What happens when cultures hold internally coherent values that genuinely clash with our own, and no biological consensus can bridge the gap? The American pragmatist philosopher [Richard Rorty](https://plato.stanford.edu/entries/rorty/) offered a radically candid answer. Rorty argued that we must abandon the search for objective foundations and accept that our commitment to human rights is a historically contingent, subjective preference—what he called a "sentimental education." Under this view, when we interfere to stop a practice like slavery or honor killings in another culture, we are not acting as agents of universal truth. Instead, we are acting as partisans for a preferred way of life. Intervention is not justified by a philosophical proof, but by a political and aesthetic struggle to expand solidarity. We fight for our subjective values because we believe they lead to a more free, less cruel world, fully aware that our justification is historically situated.