What Is Moral Progress? How Ethical Standards Evolve Over Time
In 1780, the year the Pennsylvania Gradual Abolition Act became the first emancipation legislation in the Western hemisphere, the vast majority of humans alive on Earth considered the ownership of other humans to be a normal, morally acceptable feature of social life. Slavery had existed in virtually every complex civilization for thousands of years--in ancient Greece, Rome, China, India, the Islamic world, sub-Saharan Africa, and the pre-Columbian Americas. Aristotle, one of the most brilliant minds in human history, argued in his Politics that some people were "natural slaves" whose subordination was both justified and beneficial to master and slave alike. This was not a fringe position. It represented mainstream moral thinking across cultures and millennia.
Within roughly 120 years--an eyeblink in the span of human civilization--chattel slavery was formally abolished in nearly every nation on Earth. The Brazilian Golden Law of 1888 ended the last major state-sanctioned system of chattel slavery in the Western world. Today, the moral consensus has reversed so completely that defending slavery as a legitimate institution would place someone outside the boundaries of acceptable discourse in virtually any society. The Universal Declaration of Human Rights (1948) states flatly that "no one shall be held in slavery or servitude" and that "slavery and the slave trade shall be prohibited in all their forms."
Was this change moral progress? The question seems almost absurd--of course moving from widespread acceptance of slavery to its near-universal condemnation represents improvement. But the concept of moral progress raises philosophical difficulties that are far more challenging than the slavery case might suggest. What standard are we using to judge that the change was progressive rather than merely different? If the standard comes from within our own moral framework, how do we know our framework is better rather than just later? If the standard is supposed to be objective, where does it come from, and how do we access it? And if our moral thinking has been wrong about so many things for so long, what reason do we have to think we have gotten things right now?
These questions matter because the concept of moral progress does important work. It underwrites reform movements, justifies legal and institutional change, and provides grounds for hope that human societies can improve. If moral progress is real, the abolition of slavery was not just a cultural shift but a genuine achievement--humanity getting closer to moral truth. If moral progress is illusory, then our current moral convictions, however confident, are no more likely to be correct than those of slaveholding societies, and future generations are as likely to judge us as moral barbarians as we judge our ancestors.
Defining Moral Progress: What Would It Even Mean?
Before asking whether moral progress has occurred, we need to clarify what the concept means. Several distinct definitions have been proposed, and they carry different philosophical commitments.
Progress as Expanding the Circle of Moral Concern
The historian W.E.H. Lecky first articulated this idea in 1869, and the philosopher Peter Singer developed it extensively. On this view, moral progress consists of the gradual expansion of the circle of beings whose interests are given moral consideration. Across human history, the circle has expanded from immediate family and kin group, to tribe, to nation, to all humans (at least in principle), and perhaps to sentient animals and ecosystems.
Ancient Greek democracy, which excluded women, slaves, and foreigners, recognized the moral standing of a small circle. The Enlightenment expanded the circle to include all men (but not yet women, non-Europeans, or the enslaved). The 19th century expanded it further through abolition and the beginnings of women's suffrage. The 20th century expanded it to include people of all races, genders, and sexual orientations--at least in aspiration if not yet fully in practice. Singer has argued that the next expansion should include all sentient animals, whose suffering, he contends, deserves moral consideration equal to comparable human suffering.
This model of progress is intuitively powerful. It captures much of what most people mean when they claim that moral improvement has occurred. But it faces the challenge of explaining why an expanding circle represents progress rather than mere change. One possible answer: because all sentient beings really do have morally relevant interests, and recognizing those interests represents a better understanding of moral reality. But this answer presupposes moral realism--the view that moral truths exist independently of human beliefs about them--which is itself philosophically contested.
Progress as Reduction of Suffering
A more empirical approach defines moral progress as the reduction of avoidable suffering and increase in wellbeing across human populations. Steven Pinker, in The Better Angels of Our Nature (2011) and Enlightenment Now (2018), documented substantial declines in violence, cruelty, and suffering over historical time. Per-capita rates of death in warfare, murder, torture, and other forms of violence have declined dramatically over centuries and millennia, even accounting for the catastrophic violence of the 20th century.
On this measure, moral progress is real and substantial:
| Indicator | Historical Baseline | Current Status | Direction |
|---|---|---|---|
| Slavery | Legal in nearly all civilizations for millennia | Formally abolished worldwide; illegal everywhere | Major improvement |
| Homicide rates | 30-100 per 100,000 in medieval Europe | 1-5 per 100,000 in modern Western nations | Dramatic decline |
| Judicial torture | Standard legal practice through 18th century | Prohibited by international law; practiced covertly if at all | Major improvement |
| Women's legal status | Property of fathers/husbands in most cultures | Formal legal equality in most nations | Major improvement |
| Child labor | Universal norm through industrial era | Prohibited in most nations; declining globally | Significant improvement |
| Death in warfare | 15-25% of males in pre-state societies | Less than 1% in modern era (despite world wars) | Dramatic decline |
| Religious persecution | Execution for heresy, forced conversion standard | Freedom of conscience legally protected in most nations | Major improvement |
| Cruel punishment | Public torture, mutilation, burning alive | Imprisonment as dominant punishment; capital punishment declining | Major improvement |
The suffering-reduction model has the advantage of being empirically measurable and philosophically modest--it does not require agreement on a complete moral theory, only on the minimal claim that suffering is bad and its reduction is good. But critics note that defining progress entirely in terms of suffering reduction collapses moral progress into a single dimension and ignores other morally important considerations like justice, dignity, autonomy, and meaning.
Progress as Improved Moral Knowledge
A more ambitious definition treats moral progress as analogous to scientific progress--the gradual accumulation of moral knowledge, the correction of moral errors, and the refinement of moral understanding. Just as science has progressed from geocentrism to heliocentrism, from humoral theory to germ theory, from Newtonian mechanics to general relativity, moral thinking has progressed from accepting slavery to recognizing universal human dignity, from denying women's rationality to recognizing gender equality, from treating homosexuality as a moral disorder to recognizing it as a normal variation of human sexuality.
This model is the most philosophically demanding because it presupposes that there are moral facts to be known--that moral claims can be true or false in a way that is independent of human opinion. Moral realists embrace this implication. Moral anti-realists--those who deny that objective moral facts exist--must reject this definition of progress or reinterpret it in less metaphysically loaded terms.
Evidence That Moral Progress Has Occurred
The case for genuine moral progress rests on several converging lines of evidence.
The Abolition of Slavery
The abolition of slavery is perhaps the clearest candidate for unambiguous moral progress. For millennia, the enslavement of human beings was practiced, defended, and morally accepted across virtually all complex civilizations. Within roughly a century, a global movement dismantled the institution, delegitimized it morally, and established its prohibition as a cornerstone of international law.
The abolition movement was driven not by economic changes alone (though economic factors contributed) but by moral arguments--claims about human equality, natural rights, the inherent dignity of every person, and the wrongness of treating humans as property. Quaker religious convictions, Enlightenment philosophical reasoning, and the testimony of enslaved people themselves combined to shift moral understanding in ways that purely economic or political explanations cannot fully account for.
The Expansion of Rights
The progressive expansion of legal and political rights to previously excluded groups represents another strong candidate for moral progress. The extension of suffrage to non-property-owning men, then to women, then to racial minorities; the legal prohibition of discrimination based on race, sex, religion, disability, and sexual orientation; the recognition of indigenous peoples' rights; the establishment of children's rights--each expansion involved recognizing the moral standing of people whose claims had previously been dismissed or ignored.
These expansions were not automatic or inevitable. Each required sustained moral argument, political struggle, and often considerable sacrifice by those demanding recognition. The fact that these expansions occurred through moral persuasion--through changing minds about who deserves moral consideration--supports the claim that they represent genuine moral learning rather than mere cultural drift.
The Decline of Accepted Cruelty
Historical practices that were once considered normal, entertaining, or even virtuous are now widely regarded as barbaric: public executions as popular entertainment, bear-baiting and dog-fighting as sport, the torture of suspected witches, the routine corporal punishment of children, the branding of criminals, the display of human "curiosities" in circuses and exhibitions. The fact that these practices were abandoned not because they became impractical but because moral sensibilities changed suggests genuine improvement in moral perception.
Arguments Against Moral Progress
The case for moral progress is far from settled. Serious arguments challenge the concept from several directions.
The Measurement Problem
Moral progress requires a standard against which change can be evaluated as improvement. But where does this standard come from? If it comes from our current moral framework, we are using our own convictions to validate our own convictions--a circular argument. Every era in history believed its moral framework represented advancement over what came before. Slaveholders believed they were more civilized than the "savages" they enslaved. Victorian moralists believed they were more refined than their predecessors. What reason do we have to think our own confidence is better justified than theirs?
The philosopher Alasdair MacIntyre has argued that contemporary moral discourse is in a state of profound disorder--that we possess fragments of older moral traditions without the coherent frameworks that once gave them meaning. If MacIntyre is right, what appears to be moral progress might actually be moral fragmentation masquerading as improvement.
The New Atrocities Problem
Claims of moral progress must contend with the fact that new forms of moral horror have accompanied the disappearance of old ones. The 20th century, which saw unprecedented expansion of rights and freedoms, also produced the Holocaust, the Gulag, the Cambodian genocide, Mao's famine, the Rwandan genocide, and the atomic bombings of Hiroshima and Nagasaki. Industrial technology created the capacity for mass killing on a scale that pre-modern societies could not have imagined.
Critics argue that moral progress may be domain-specific rather than general. We may have improved in some areas (treatment of racial minorities, legal protections for women) while stagnating or regressing in others (environmental destruction, weapons of mass destruction, economic inequality). If progress in some domains is purchased at the cost of regression in others, the net assessment becomes far less clear.
The Contingency Problem
Much of what we identify as moral progress may be the contingent result of economic, technological, and political changes rather than genuine moral learning. Slavery was abolished partly because industrial economies made it economically unnecessary and partly because democratic political systems created space for reform movements. If slavery had remained economically essential, would moral arguments alone have been sufficient to end it?
This argument does not deny that moral change occurred but questions whether it represents genuine moral progress--improvement in moral understanding--or merely the byproduct of non-moral changes that happened to produce outcomes we now approve of. If moral convictions are primarily shaped by material conditions, then what we call moral progress may be economic and technological progress with a moral veneer.
The Presentism Problem
Evaluating the past by present moral standards--what historians call presentism--raises its own difficulties. Judging Thomas Jefferson for enslaving people applies a moral standard that, while correct by our lights, was not widely available in his cultural context. Some philosophers argue that moral agents can only be fairly evaluated by the standards available to them in their time and place.
This does not mean past moral practices were acceptable. But it complicates the narrative of progress by asking whether the people of the past were genuinely worse moral agents or simply people of ordinary moral capacity operating within frameworks that were, through no individual's fault, deeply flawed. If the latter, then what changed was not individual moral quality but the moral environment--the available arguments, the accessible perspectives, the range of moral options people could realistically consider.
Who Drives Moral Progress?
If moral progress is real, understanding its mechanisms matters for promoting further progress. Several factors appear to drive moral change.
Moral Entrepreneurs and Social Movements
Moral progress rarely emerges from gradual, distributed shifts in public opinion. More often, it is driven by moral entrepreneurs--individuals and organized movements that champion moral positions initially rejected by the majority. Abolitionists, suffragettes, civil rights activists, disability rights advocates, and LGBTQ rights organizations all challenged prevailing moral consensus and eventually shifted it.
These movements succeed through a combination of moral argument, emotional persuasion, strategic political action, and personal sacrifice. Martin Luther King Jr.'s "Letter from Birmingham Jail" deployed philosophical argument, biblical authority, and moral passion to challenge both legal segregation and white moderates' preference for "order" over justice. The effectiveness of this combination--not pure argument alone, not pure emotion alone--suggests that moral progress involves the whole human being, not just the reasoning faculty.
Expanding Empathy Through Contact
Psychological research strongly suggests that personal contact across group boundaries is one of the most powerful mechanisms for moral change. Gordon Allport's "contact hypothesis" (1954), now supported by decades of research, holds that prejudice decreases when members of different groups interact under conditions of equal status, common goals, and institutional support.
The rapid shift in attitudes toward homosexuality in many Western countries correlates strongly with increased visibility of gay and lesbian individuals in everyday life. As more people came to know openly gay friends, family members, coworkers, and neighbors, the abstract moral question ("Is homosexuality wrong?") became a concrete human question ("Is my son wrong for who he is?"). The concretization of moral questions through personal experience appears to drive intuitive moral change that abstract arguments alone often cannot achieve.
Institutional and Legal Change
Sometimes moral progress is driven not from the ground up but from the top down, through institutional and legal changes that reshape moral norms. The desegregation of the U.S. military in 1948, the Civil Rights Act of 1964, and court decisions like Brown v. Board of Education did not merely reflect changing moral attitudes; they shaped those attitudes by establishing new behavioral norms and creating conditions for cross-group contact.
Law and institutions can function as moral teachers, creating expectations that gradually become internalized. When seatbelt laws were first enacted, many people resented them. Within a generation, wearing seatbelts became a moral norm--failing to buckle up was seen not just as illegal but as irresponsible. Similar processes appear to operate with civil rights legislation, environmental regulation, and workplace safety standards.
Technology and Information
Technological change creates new moral information and new moral possibilities. The printing press enabled the widespread distribution of abolitionist literature and slave narratives. Photography documented the horrors of war, child labor, and famine in ways that written accounts could not match. Television brought the violence of civil rights confrontations into American living rooms, shifting public opinion. The internet has enabled global moral communities, rapid dissemination of information about injustice, and coordination of moral activism.
Technology also creates new moral challenges--surveillance, weapons technology, environmental destruction, artificial intelligence--that demand new moral thinking. Whether the net effect of technological change on moral progress is positive depends on whether moral development keeps pace with technological capability, a question that becomes more urgent as technology accelerates.
What Future Moral Progress Might Look Like
If past moral progress provides any guide, future generations are likely to judge some of our current practices as morally indefensible. Identifying candidates for future moral revision is speculative but instructive--it exercises the same moral imagination that abolitionists, suffragettes, and civil rights activists exercised when they challenged their own era's moral certainties.
Animal Welfare
The philosopher Peter Singer has argued since the 1970s that the treatment of animals in factory farming represents a moral catastrophe comparable in scale (though different in kind) to historical atrocities against humans. Billions of sentient creatures are confined in conditions of extreme suffering for the production of food that could be obtained through other means. If future moral progress follows the pattern of expanding the circle of moral concern, the treatment of animals is a strong candidate for the next major revision.
Global Economic Justice
The distribution of resources between wealthy and poor nations creates a situation where accident of birth largely determines whether a person lives in comfort or in desperate poverty. If the moral arbitrariness of birth circumstances is taken seriously--as Rawls argued it should be--then the current global economic order may be viewed by future generations as we view historical caste systems: as a morally indefensible arrangement in which life prospects are determined by morally irrelevant factors.
Environmental Ethics and Future Generations
Current environmental practices--fossil fuel consumption, biodiversity destruction, resource depletion--impose enormous costs on future generations who have no voice in present decisions. If moral progress involves expanding the circle of moral concern, extending that circle forward in time to include people who do not yet exist represents a significant and potentially transformative moral expansion.
Criminal Justice and Punishment
The mass incarceration systems of the United States and other countries, the persistence of the death penalty, and the conditions of confinement in many prisons may be viewed by future generations with the same discomfort we feel examining historical practices of judicial torture and public execution. The question is not whether punishment is sometimes justified but whether current practices are proportionate, humane, and effective--and accumulating evidence suggests they often are not.
The Paradox of Moral Confidence
Perhaps the most important lesson from the history of moral change is epistemic humility about our own moral convictions. Every generation has been confident in its moral framework. Every generation has been wrong about some things, often things that seemed most obviously correct at the time. This pattern should make us cautious about our own certainties.
But humility should not collapse into paralysis. The fact that future generations may judge us harshly does not mean we should stop making moral judgments or pursuing moral improvement. Abolitionists did not wait for philosophical certainty before opposing slavery. Civil rights activists did not wait for a complete theory of justice before demanding equal treatment. Moral progress has always been driven by people who acted on their best moral understanding while remaining open to further revision.
The philosopher Kwame Anthony Appiah has argued that moral revolutions typically follow a pattern: practices that were long accepted come under moral scrutiny, arguments against them become available and gradually persuasive, a tipping point is reached where the practice is suddenly viewed as indefensible, and within a generation the new moral standard becomes so firmly established that it is difficult to understand how the old practice was ever accepted. Appiah calls this pattern the "honor revolution"--the point where engaging in the practice (or defending it) becomes a source of shame rather than pride.
Understanding this pattern does not tell us which of our current practices will undergo moral revolution next. But it tells us that revolution is likely, that it will seem obvious in retrospect, and that the best preparation is not certainty about specific future changes but a general stance of moral seriousness combined with intellectual humility--a commitment to doing what seems right now while acknowledging that our understanding of what is right will continue to evolve.
Moral progress is neither guaranteed nor impossible. It is an achievement--hard-won, always incomplete, sometimes reversed, dependent on moral courage and institutional support and favorable circumstances. Recognizing it as an achievement rather than an inevitability is itself a form of moral maturity: it means taking responsibility for the moral world we create rather than assuming that history will deliver improvement on its own.
References and Further Reading
Singer, P. (2011). The Expanding Circle: Ethics, Evolution, and Moral Progress. Princeton University Press. https://en.wikipedia.org/wiki/The_Expanding_Circle
Pinker, S. (2011). The Better Angels of Our Nature: Why Violence Has Declined. Viking. https://en.wikipedia.org/wiki/The_Better_Angels_of_Our_Nature
Appiah, K.A. (2010). The Honor Code: How Moral Revolutions Happen. W.W. Norton. https://en.wikipedia.org/wiki/The_Honor_Code
Nussbaum, M. (2000). Women and Human Development: The Capabilities Approach. Cambridge University Press. https://en.wikipedia.org/wiki/Capabilities_approach
Jamieson, D. (2002). "Is There Progress in Morality?" Utilitas, 14(3), 318-338. https://plato.stanford.edu/entries/progress/
Moody-Adams, M. (1999). "The Idea of Moral Progress." Metaphilosophy, 30(3), 168-185. https://www.jstor.org/stable/24439424