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?

Why is it that we can comfortably treat our culinary choices as matters of personal taste, yet we react with outrage if someone suggests that human chattel slavery is merely a "cultural preference"? This paradox reveals that we do not apply moral subjectivity uniformly. Instead, our minds operate on a sliding scale of moral objectivity, a phenomenon known in cognitive science and psychology as **moralization**. We dynamically shift our ethical framing depending on the topic, treating some issues as absolute, universal laws and others as flexible, subjective conventions. ## The Spectrum of Moralization: From Meat to Slavery To understand this selective subjectivity, we can look at how public consciousness shifts over time. In his influential research on [Moralization](https://en.wikipedia.org/wiki/Moralization), psychologist Paul Rozin explored how neutral preferences transform into strict moral values. Consider the contemporary debate over eating meat. For many, vegetarianism is a subjective preference, akin to liking spicy food. For others, it has undergone moralization and is viewed as a strict ethical duty. However, even the most ardent vegans rarely view meat-eating with the same category of absolute, historical condemnation that we reserve for transatlantic slavery. This distinction rests on what philosopher Joshua Greene calls the "tribal" versus "universal" settings of our moral brains. In his book *Moral Tribes*, Greene argues that our brains possess both automatic, emotion-driven settings and manual, cognitive settings: > "The moral brain is like a dual-mode camera with automatic settings... and a manual mode... Moral intuition is an automatic cognitive device, a shortcut for solving the complex cognitive problems of social life." When evaluating historical atrocities like slavery, our "automatic" settings trigger an uncompromising, objective response because the survival and cooperation of our species rely on absolute prohibitions against in-group harm. For evolving issues like animal welfare or environmentalism, we often remain in "manual mode," allowing us to tolerate subjective disagreement because the social contract is still actively negotiating these boundaries. ## The "Asymmetry Thesis" in Action This selective application of subjectivity creates what philosophers call the **Asymmetry Thesis**. We behave as moral realists when the stakes involve immediate, physical harm to humans, but we lean toward subjectivism when the stakes involve purity, tradition, or emerging ethical frontiers. 1. **The Core Harm Principle:** Actions that violate basic bodily autonomy (e.g., slavery, murder) are pushed to the extreme "objective" end of our cognitive spectrum. We instinctively reject subjectivism here because treating slavery as "subjective" threatens the very foundation of social coordination. 2. **The Frontier of Moral Expansion:** Issues like dietary choices, intellectual property, or even assisted dying exist in a zone of active debate. Because society has not reached a consensus, we tolerate moral subjectivism as a cognitive buffer, allowing us to disagree without immediately tribalizing or dehumanizing our neighbors. Ultimately, our response to moral subjectivity is not a coherent philosophical stance, but a psychological survival mechanism. We are subjective where we can afford to be, and objective where we must be.