Navigating the Constants and Variables in Moral Philosophy

Morality is often assumed to be a fixed set of rules – a clear map of right and wrong handed down through the ages. But spend a moment with moral philosophy and you quickly realize something more complex is at work. Some moral principles appear to be deeply stable, found across virtually every human culture and every era of history. Others shift dramatically depending on time, place, religion, and social change. Understanding what stays constant and what changes in morality – and why – is one of the most important questions in ethical thought.

What do we mean by “constants” in morality? 🔗

Moral constants are principles that hold across cultures, historical periods, and contexts. They are not invented by any single tradition; they seem to arise wherever human beings live together in communities. Empirical studies across societies have consistently shown that virtually every human community has moral rules dealing with family duties, personal welfare, truth-telling, and promise-keeping. These are not coincidences – they point to something structurally necessary in human social life.

A landmark study by Oxford University researchers analyzing ethnographic records from 60 societies found seven cooperative behaviors that were considered morally good across all of them: helping kin, helping one’s group, reciprocating, being brave, respecting superiors, dividing resources fairly, and respecting property. Crucially, there were no counter-examples – no society where any of these behaviors was considered morally bad. These principles appeared consistently across continents, suggesting they are not culturally contingent but rooted in the demands of human cooperation itself.

From a developmental perspective, cross-cultural research in psychology has found that children as young as three months old show a preference for prosocial behaviors – favoring those who help others over those who harm or obstruct them. By around age ten, children in most cultures independently arrive at the conviction that harming others, physically or by violating their rights, is wrong. This is not taught in the same way across cultures; it appears to emerge from something foundational in human moral cognition.

The role of natural law and human dignity 🔗

Philosophers have long tried to explain why certain moral principles are constant. One of the oldest answers is natural law – the idea that some moral truths are grounded in the structure of reality or human nature itself, discoverable through reason. Scholars working on universal ethics have argued that this foundation can be understood in both religious and secular terms, and that human dignity – as a principle independent of any worldview – may serve as the single most reliable anchor for universal moral norms.

Immanuel Kant gave this idea its most systematic philosophical form. For Kant, morality is grounded not in tradition, consequences, or emotion, but in reason itself. His famous categorical imperative – act only according to that maxim you could will to become a universal law – is precisely an attempt to identify a constant, rational foundation for ethics. Kant argued that because all rational agents share the same practical reason, the moral law binds everyone equally, regardless of culture or circumstance. Morality, for him, was not a product of history but a requirement of rationality.

What changes? The variables in moral life 🔗

While certain principles may be constant, morality is not applied in a vacuum. The way universal principles are interpreted, prioritized, and expressed varies enormously across time and culture. These variations – the moral variables – are just as philosophically significant as the constants.

Culture and social norms as moral variables 🔗

What counts as acceptable behavior within a shared principle can differ widely. Consider the near-universal principle of caring for one’s parents. Some societies have held practices that seem shocking in other contexts – yet the underlying moral commitment (filial duty) remains consistent. The surface expression changes; the underlying principle does not. Similarly, practices like polygamy, particular dietary restrictions, or gender roles have been considered morally obligatory in some societies and condemned in others, reflecting how deeply cultural frameworks shape the application of shared values.

Research in cross-cultural moral psychology identifies at least three broad ethical orientations that cultures emphasize differently: an ethics of Autonomy (focused on individual rights and freedoms, common in Western societies), an ethics of Community (focused on group solidarity and roles), and an ethics of Divinity (focused on spiritual purity and sacred order). No single orientation captures the full moral landscape of humanity – different cultures weight them differently, producing genuinely distinct moral outlooks even when the foundational concerns are shared.

The evolution of human consciousness and moral knowledge 🔗

Human moral knowledge is not static. Our understanding of who counts as a moral subject – who deserves moral consideration – has expanded dramatically over time. The abolition of slavery, the extension of rights to women, the growing recognition of animal welfare and environmental responsibility: these are not simply changes in social fashion. They represent an expanding circle of moral concern driven by expanding human consciousness, greater knowledge, and refined ethical reasoning.

This is the sense in which morality can be said to progress. Not because the underlying principles change, but because our capacity to apply them consistently and comprehensively improves. Moral development theory, drawing on the work of Piaget and Kohlberg, suggests that moral reasoning advances through identifiable stages – from simple rule-following based on reward and punishment, to principled reasoning based on justice and universal rights. The same developmental arc that plays out in individuals may, in a broader sense, play out across human history.

New moral questions also arise that earlier eras could not have anticipated. Issues such as AI ethics, genetic engineering, climate responsibility, and digital privacy were not part of any traditional moral framework. As moral philosophers note, applying existing principles to genuinely novel situations requires ongoing moral reasoning – not a rejection of constants, but a careful and often difficult extension of them.

Moral relativism versus moral absolutism: a false choice? 🔗

The recognition that morality contains both constants and variables has historically produced two extreme responses. Moral absolutism holds that certain moral truths apply to all people at all times, regardless of context. Moral relativism holds that moral judgments are always relative to the culture or individual making them, and that no universal moral standard exists.

Both extremes face serious difficulties. Critics of moral relativism argue that it leads to the troubling conclusion that anything goes – that practices like slavery or apartheid cannot be condemned if they were sanctioned by the norms of their time. If moral truth is entirely relative, there is no basis for moral progress, reform, or cross-cultural criticism. Yet strict absolutism also struggles when universal principles conflict with each other, or when applying a fixed rule causes demonstrable harm in a particular context.

Most careful moral philosophers occupy a middle position. They recognize that fundamental moral principles – avoiding harm, treating persons with dignity, honoring basic duties of fairness – are not culturally relative. But they also acknowledge that the application of these principles requires sensitivity to context, circumstance, and the full range of relevant moral considerations. As the Markkula Center for Applied Ethics puts it, societies may differ in how they apply fundamental moral principles while still sharing the underlying principles themselves.

Can we achieve moral certitude? 🔗

The question of whether genuine moral certainty is possible sits at the heart of this debate. If morality contains both stable constants and evolving variables, how do we know when we have got it right?

Different ethical frameworks approach this differently. Deontological ethics, especially in Kant’s formulation, offers a form of moral certitude grounded in reason: an action is morally right if the maxim behind it could serve as a universal law. For Kant, moral certainty comes not from predicting consequences or consulting cultural norms, but from rational consistency – from asking whether a principle could hold for all rational beings without contradiction.

Consequentialist theories like utilitarianism offer a different anchor: certainty lies in the outcomes. An action is right if it maximizes well-being, wrong if it produces more harm than good. This approach is more flexible and responsive to context, but it faces its own difficulties – measuring and comparing welfare across persons and situations is genuinely hard, and it can, in principle, justify actions that violate widely shared moral intuitions.

Virtue ethics offers a third path, shifting attention from rules or outcomes to moral character. On this view, moral certainty is not a matter of applying the right formula but of developing practical wisdom – the capacity to perceive the morally relevant features of a situation and respond well. This is precisely the kind of wisdom that allows someone to apply constant moral principles to endlessly variable human circumstances.

What these frameworks share is the conviction that moral knowledge, while sometimes difficult to achieve, is genuine knowledge – not mere preference or cultural habit. Psychological and philosophical research suggests that morality centrally involves obligatory concerns with others’ welfare, rights, fairness, and justice. These are not arbitrary; they track something real about what it means for human beings to live together well.

Moral knowledge as a progressive enterprise 🔗

Perhaps the most productive way to understand the constants and variables in morality is to see moral knowledge as progressive – not in the sense that anything goes or that all change is improvement, but in the sense that our collective grasp of moral truth can deepen over time. Historical moral progress – the recognition that enslaved people are full moral persons, that women deserve equal rights, that future generations have moral claims on us – was not a departure from moral constants. It was a more consistent and rigorous application of them.

This means that moral uncertainty is not a reason for moral paralysis. The presence of genuinely hard moral questions, of cultural diversity in moral practice, and of evolving human consciousness does not mean that morality is merely subjective. It means that moral reasoning is an ongoing task – one that requires both fidelity to fundamental principles and the intellectual humility to recognize that our current understanding may be incomplete.

The constants in morality – harm avoidance, fairness, dignity, reciprocity – give us stable ground to stand on. The variables – the cultural, historical, and situational factors that shape how we apply those principles – ensure that moral reasoning remains alive, responsive, and genuinely engaged with the complexity of human life. Neither side of this equation can be discarded. Together, they reflect what morality actually is: a human practice with universal roots and an unfinished history.

What do you think? If moral knowledge can genuinely progress over time, what does that suggest about moral judgments we currently take for granted – might future generations look back on some of our accepted practices the way we look back on slavery or the denial of women’s rights? And if certain moral constants truly exist across all cultures, why do moral disagreements – even on fundamental questions – remain so persistent and difficult to resolve?

References

1. https://www.britannica.com/topic/morality
2. https://www.ox.ac.uk/news/2019-02-11-seven-moral-rules-found-all-around-world
3. https://open.maricopa.edu/culturepsychology/chapter/culture-and-morality/
4. https://link.springer.com/article/10.1007/s43545-022-00350-7
5. https://iep.utm.edu/kantview/
6. https://www.scu.edu/ethics/ethics-resources/ethical-decision-making/ethical-relativism/
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC8710723/
8. https://iep.utm.edu/moraldev/
9. https://plato.stanford.edu/entries/moral-theory/
10. https://iep.utm.edu/moral-re/
11. https://iep.utm.edu/kantmeta/
12. https://pmc.ncbi.nlm.nih.gov/articles/PMC10923505/