Michael Shermer: THE MORAL ARC

Subtitled: How Science and Reason Lead Humanity toward Truth, Justice, and Freedom

(Henry Holt, January 2015, 541pp, including 55pp of notes, 30pp of bibliography, and 15pp of acknowledgments and index)

This is Michael Shermer’s magnus opus, perhaps, culminating a running theme in his earlier books from WHY PEOPLE BELIEVE WEIRD THINGS in 1997 (reviewed here), HOW WE BELIEVE in 2000 (here), THE SCIENCE OF GOOD & EVIL (which I haven’t read yet), and THE BELIEVING BRAIN in 2011 (ditto). Not to mention WHY DARWIN MATTERS in 2006 (here) and other books about the territory between science and irrationality. Shermer was founder and editor of Skeptic magazine, and his perspective is interesting because for a while in high school he was a born-again-Christian until, as he put it in the Darwin book, “The scales fell from my eyes! It turned out that the creationist literature I was reading presented a Darwinian cardboard cutout that a child could knock down.” Also, he was a cross-country bicyclist for a while.

The book is spiritual kin to Steven Pinker’s THE BETTER ANGELS OF OUR NATURE (partial summary) and I even sat down to read this Shermer book soon after it came out, until seeing in the opening pages Shermer himself crediting Pinker’s book. Eventually I did read Pinker’s book, and its sequel, and so eventually just last month, despite not having read a couple of Shermer’s earlier books in that thread above, plowed through this one, his longest.


  • The basic thesis is that morality has improved over time, especially in recent centuries and decades, and the cause of this is the application of reason and science. Better understanding of the real world helps us avoid factual errors that generate behaviors that our ancestors and their religions took for granted but which we increasingly regard as immoral.
  • Shermer defines moral progress as “the improvement in the survival and flourishing of sentient beings.”
  • The conventional wisdom that science can have nothing to say about religion, and that morality is impossible without guidance from holy books, is wrong, on both counts.
  • Key ideas include the “principle of interchangeable perspectives” and the virtue of continuous (rather than black and white) thinking.
  • Science and reason are the drivers of moral progress by revealing the world as it actually is, thereby correcting the mistaken ideas of people with magical views of the world. The ancients didn’t understand causality, or coincidence. [[ And many people still don’t. ]] This understanding of the world began with the scientific revolution (Copernicus to Newton) and the Age of Reason and the Enlightenment (Newton to the French Revolution).
  • Religion (and least, western religion) is not a source of morality or moral progress. When moral progress has been made, the churches have resisted it and are the last to accept it. Religions are tribal and xenophobic by nature. The Bible is one of the most immoral books of all time, full of tribal warlords fighting over land and women, and a jealous and vengeful God who prohibits killing except when he says it’s OK. Religious nations, and states (within the US) have higher rates of social dysfunctions than less religious ones.
  • Shermer offers his own Decalogue, and critiques the traditional set of ten commandments.
  • The book continues with case studies of how morality has improved regarding slaves, women, gays, and animals.
  • And finally considers issues of moral regress and evil; free will and moral culpability; competing notions of moral justice; and the future of moral progress.

Now for a rather longer summary.


Prologue: Bending the Moral Arc

  • Shermer invokes Martin Luther King: “The arc of the moral universe is long, but it bends toward justice.”
  • Page 3.4: “…the arc of the moral universe bends not merely toward justice, but also toward truth and freedom, and that these positive outcomes have largely been the product of societies moving toward more secular forms of governance and politics, law and jurisprudence, moral reasoning and ethical analysis. Over time it has become less acceptable to argue that my beliefs, morals, and ways of life are better than yours simply because they are mine, or because they are traditional, or because my religion is better than your religion, or because my God is the One True God and yours is not, or because my nation can pound the crap out of your nation. It is no longer acceptable to simply assert your moral beliefs; you have to provide reasons for them, and those reasons had better be grounded in rational arguments and empirical evidence or else they will likely be ignored of rejected.
  • Author notes the prevalence of bad news—as many others have noted, driven by evolutionarily derived attention spans—might seem to counter this thesis; Pinker noted the same thing.
  • Science and reason have been under attack: by right-wing ideologues, religious-right conservatives, even left-wing postmodernists, antivaxxers, anti-GMO activists, etc.
  • Page 6.6: “Evidence-based reasoning is the hallmark of science today. It embodies the principles of object data, theoretical explanation, experimental methodology, peer review, public transparency and open criticism, and trial and error as the most reliable means of determining who is right—not only about the natural world, but about the social and moral worlds as well. In this sense many apparently immoral beliefs are actually factual errors based on incorrect causal theories. Today we hold that it is immoral to burn women as witches, but the reason our European ancestors in the Middle Ages strapped women on a pyre and torched them was because believe that witches caused crop failure, weather anomalies, diseases, and various other maladies and misfortunes. Now that we have a scientific understanding of agriculture, climate, disease, and other causal vectors – including the role of chance – the witch theory of causality has fallen into disuse; what was a seemingly moral matter was actually a factual mistake.
  • [[ Comment: this is a running theme of the book, and might well apply to current issues of abortion and climate change, if so many people weren’t beholden to “stories” (beliefs) in the face of evidence and reason. ]]
  • Thus “One path (among many) to a more moral world is to get people to quite believing in absurdities. Science and reason are the best methods for doing that.”

Part I: The Moral Arc Explained

Chapter 1, Toward a Science of Morality

  • Moral progress is the improvement in the survival and flourishing of sentient beings. [[ Similar to Sam Harris’ definition. ]] Individual sacrifice for the good of a group is thus immoral. Author gives thorough definitions of what he means by science (p15) and reason (p16), and stipulates that the latter is subject to various cognitive biases.
  • A key Shermer idea is his “principle of interchangeable perspectives” – think about a situation from the other’s point of view. The moral sphere has the self at the center, expanding to the entire species and beyond to other species in the outer rings (p20).
  • Another key Shermer idea: the virtue of continuous thinking. Along continua between good and evil, altruistic and selfish. As opposed to the black and white thinking of so many people.
  • We can understand how the world came to be without explaining why we should want it. We take what science has discovered about the world to apply it to the way we would like the world to be.
  • He considers the evolutionary logic of emotions, which are like a thermostat, to maintain homeostasis. Examples of aggressive emotion, moral emotions, moral dilemmas.
  • Thus there must be rules, and they must be enforced, to encourage the right thing and discourage the wrong thing. Solve the free rider problem by eliminating anonymity.

Chapter 2, The Morality of War, Terror, and Deterrence

  • Discussion of pirate morality; the evolutionary logic of deterrence; the problem with nuclear weapons.
  • There are seven myths about terrorists that need to be debunked: that they are pure evil; that they are organized; are diabolical geniuses; poor and uneducated; that terrorism is a deadly problem; that they will use a nuclear or dirty bomb; and finally that terrorism works. (E.g. in one study only 2 of 42 terrorist organizations achieved anything.)
  • The long debate about whether humans are essentially peaceful, or essentially violent. The myth is that people in primitive societies lived ‘in harmony with nature’; in fact, prehistoric people were far more likely to die violently. (The broad theme of Pinker’s book.) The debate has turned ideological; but people who think life was better in simpler times are deluding themselves.

Ch 3, Why Science and Reason are the Drivers of Moral Progress

  • Because when people held magical views of the world, they justified actions we should find barbaric. They didn’t understand causality, or coincidence. The difference between us and them is science.
  • People who believe in witches or demons, who don’t accept natural causes, aren’t evil, they’re misinformed.
  • The solution to past immorality and barbaric actions was science, beginning with Newton: everything has natural causes.
  • Many examples, following the scientific revolution (Copernicus to Newton) and the age of reason and the Enlightenment (Newton to the French Revolution). The book of authority vs the book of nature. Leviathan states; trade and commerce and democracy.
  • Politics is mostly about finding the balance between individual liberty and social order. Preserve, or change? Attitudes are partly inherited, emerging from temperaments, e.g. feelings of disgust. Moral values cluster. The problem of how to reach a livable middle ground must be solved by reason. Both sides are necessary. And we can make the scientific case that liberal democracy, market economics, and international transparency are necessary for reaching any of the various peaks of Harris’s moral landscape.
  • Summary p147b, p148, worth quoting.

Ch 4, Why Religion Is Not the Source of Moral Progress

  • Jesus had many admirable things to say, but religion has also promoted numerous crusades, inquisitions, witch hunts, conquistadors, and wars of religion, just in the western world. No matter what their individual causes, all share religion. When moral progress *is* made, e.g. abolition of slavery, women’s rights, gay rights, religion is very slow to endorse it.
  • The rules set down by religions didn’t apply to sentient beings outside their own tribe. “Love thy neighbor” only applied to immediate kith and kind.
  • Religions are tribal and xenophobic by nature: in-group vs. out-group, the ideas of heathens and unbelievers.
  • The Bible is one of the most immoral books in all literature. A bunch of Middle Eastern tribal warlords constantly fighting over land and woman. A jealous and vengeful God. Ironically those practices made sense in an evolutionary context: powerful men have more women, more sex, more children. But that was a different time. The few positive moral commands in the Bible are overwhelmed by the tales of murder, torture, slavery, and lists of actions punishable by death.
  • Nor does the NT supersede the OT; Jesus endorses the OT laws, added new crimes, and renounced his family (just as today’s cultists do).
  • Isn’t religion good for societal health and happiness? Studies conflict, e.g. one shows the US among the most religious of nations but also very dysfunctional; homicides, incarcerations, suicides, teen pregnancies, abortion, divorces, are all high in religious nations (and religious states within the US). OTOH some studies suggest that some people are good, or engage in healthy behaviors, for the sake of delayed gratification, or the feeling that God is watching over them.
  • Shermer then ‘deconstructs’ the Decalogue, beginning p176, looking at each of the Ten Commandments and considering it against the moral progress of three millennia. The first four say nothing about morality, and appeal to polytheism, a god like the Greek gods, full of adolescent passions, and violate various US constitutional amendments. The fifth, oxymoronic; the sixth is a genuine moral principle, but the evidence of the Bible is that killing is fine if God says so. All cultures have rules like the seventh, eighth, and ninth. The tenth is the world’s first thought crime, and to follow it would undermine western capitalism.
  • Shermer then offers a “provisional rational decalogue,” which I long ago listed on my Principles page (about three screens down).

I think chapters 3 and 4 are the heart of the book. I’ll not summarize all the later chapters in as much detail.

Part II: The Moral Arc Applied” includes chapters about how the moral arc has played out with regards to slavery, women’s rights, gay rights, and animal rights. Practices like slavery, the subjugation of women and gays, the casual torture of animals, were accepted for thousands of years, and of course endorsed in the Bible. The recurring theme here is that only in the past few hundreds of years, or even decades, has the awareness the dignity of all people, the application of the “principle of interchangeable perspectives,” and the discovery that many animals are as sentient to some degree as humans and can equally feel pain and suffer, have attitudes about slaves, women, gays, and animals become more enlightened.

Part III: The Moral Arc Amended” has four more chapters on themes that identify problems and challenges of the expanding moral arc.

Ch9, Moral Regress and Pathways to Evil

  • How do we mitigate moral regress? Examples of such regress from the Nazis to psychological experiments in which subjects are taught to be cruel to other subjects and willingly comply.
  • The Nazis believed their actions were justified, on grounds of living space, or racial purity. Broadly speaking, these are examples of moral judgments based on factual errors. Blaming Jews was the equivalent of blaming of witches hundreds of years before. The solution is a better understanding of reality: that there are no witches; that the Jews were not supernatural causes of every calamity that came along.
  • We can apply the public health model to the problem of evil: treat it as an infection. We understand that the incremental steps toward evil are deindividuation, dehumanization, compliance, identification, conformity, tribalism and loyalty, and pluralistic ignorance. Many such causes and effects have been studied since World War II, and mitigated.
  • [[ My comment: again, avoid mob mentality. Don’t let the crowd, in group events or online, tell you what to think! ]]

Ch10, Moral Freedom and Responsibility

  • Here the topic is free will and moral culpability. Moral culpability presumes we are free to choose; but increasingly brain studies show our actions are deterministic. Shermer considers four ways around this paradox, enabling us to retain free will and moral responsibility.
  • These involve the modular mind; vetoing one impulse for another; free choice as part of a causal net; moral degrees of freedom.
  • From a science point of view we have studied causes of crime, and have a moral duty to change those conditions, e.g. target gangs, teach males self-control techniques, encourage couples counseling.

Ch11, Moral Justice: Retribution and Restoration

  • The origins of revenge are part of how emotions evolved to guide behavior in part for survival—whether to strike out, pull back, reject — and in part to enable larger and larger groups to survive. Humans have an innate sense of fairness. We intuit moral feelings; without them a social community would never have overcome anarchy and violence. [[ Here again is the idea cited by many writers about how our moral sense has evolved, enabling humans to become social animals. You don’t need a list of rules in a book to be moral. ]]
  • Authors goes through many examples of how societies punish those who don’t play nice, all the way from gossip to capital punishment.
  • A key distinction is retributive justice vs. restorative justice. The former is intended to deter crime. The latter involves a perpetrator who apologizes for a crime and works to make things right. Restorative justice is an exercise in the principle of interchangeable perspectives; using it can, for example, prevent a street accident from elevating into a feud between two families.
  • We see a trend in this direction with the reduction around the world of the death penalty, following the abolition of legalized torture.
  • Examples of restorative justice include Queen Elizabeth’s pardon of and apology to Alan Turing, the Treaty of Versailles, reconciliations between nations – they must be public, and are admittedly imperfect.
  • Paying reparations is more difficult, e.g. attempts in the US to compensate Native and African Americans for past injustices. Once started, such apologies and reparations might never end. At least we can make things better in the future.

Ch12, Protopia: The Future of Moral Progress

  • Civilization advances as small tribes unite into larger and larger communities. Reason and science have enabled us to do this more than any other force.
  • How far can this be extended? We know utopias invariable fail. They can’t exist because they assume, wrongly, that perfection in individuals or society is possible.
  • Instead we should aspire to a process of gradual improvement: incremental improvements, not giant leaps. [[ This echoes the practices in the engineering community of “continuous process improvement,” as I’ve described in my memoir pages. ]]
  • The number of independent political units continually shrinks, but a global Leviathan is not reasonable; people are concerned only about what affects them locally, and huge governments are given to bureaucracy.
  • The trend may be toward more smaller states, where mayors are the most important leaders. Think globally, act locally; and think historically, act rationally.
  • Post-scarcity economics may be more realistic than previously thought, the idea that we don’t have a problem of limited resources. More systems are automated; the amount of information available through the internet dwarfs that of past generations.
  • Income inequality is not as bit a problem as many think, because the entire pie is getting bigger; everyone is getting richer, even the poor. Still, it leads to some bad consequences; solutions involve taxing the wealthy and redistributing money to the poor, or restructuring capitalism so that all stakeholders are involved, not just owners.
  • Thinking big, author imagines a scale of types of civilization, numbered 1.0, 1.1, etc to 2.0: hominins in Africa; bands of hunter gatherers; tribes; chiefdoms; city-states and feudal kingdoms; nation-states; empires; electoral democracies and republics; democratic capitalism; globalism and a planetary civilization (p432-433). We’re not quite at 2.0.
  • Where does morality fit in? Eventually we might see many worlds with separate civilizations on each. Different civilizations would have different ‘amounts’ of information, and made different moral progress. We can expect some aliens will have progressed beyond ourselves. First contact might be dangerous.
  • We are made from stars, and morality can be seen as something that carbon atoms can embody given billions of years.


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