Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

As I mentioned in chapter 2 (following an observation by John Tooby), the Law of Entropy sentences us to another permanent threat. Many things must all go right for a body (and thus a mind) to function, but it takes just one thing going wrong for it to shut down permanently—a leak of blood, a constriction of air, a disabling of its microscopic clockwork. An act of aggression by one agent can end the existence of another. We are all catastrophically vulnerable to violence—but at the same time we can enjoy a fantastic benefit if we agree to refrain from violence. The Pacifist’s Dilemma—how social agents can forgo the temptation to exploit each other in exchange for the security of not being exploited—hangs over humanity like the Sword of Damocles, making peace and security a permanent quest for humanistic ethics.¹⁰ The historical decline of violence shows that it is a solvable problem.

The vulnerability of any embodied agent to violence explains why the callous, egoistic, megalomaniacal sociopath cannot remain disengaged from the arena of moral discourse (and its demand for impartiality and nonviolence) forever. If he refuses to play the game of morality, then in the eyes of everyone else he has become a mindless menace, like a germ, a wildfire, or a rampaging wolverine—something to be neutralized by brute force, no questions asked. (As Hobbes put it, “No covenants with beasts.”) Now, as long as he thinks he is eternally invulnerable, he might take that chance, but the Law of Entropy rules that out. He may tyrannize everyone for a while, but eventually the massed strength of his targets could prevail. The impossibility of eternal invulnerability creates an incentive even for callous sociopaths to re-enter the roundtable of morality. As the psychologist Peter DeScioli points out, when you face an adversary alone, your best weapon may be an ax, but when you face an adversary in front of a throng of bystanders, your best weapon may be an argument.¹¹ And he who engages in argument may be defeated by a better one. Ultimately the moral universe includes everyone who can think.

Evolution helps explain another foundation of secular morality: our capacity for sympathy (or, as the Enlightenment writers variously referred to it, benevolence, pity, imagination, or commiseration). Even if a rational agent deduces that it’s in everyone’s long-term interests to be moral, it’s hard to imagine him sticking his neck out to make a sacrifice for another’s benefit unless something gives him a nudge. The nudge needn’t come from an angel on one shoulder; evolutionary psychology explains how it comes from the emotions that make us social animals.¹² Sympathy among kin emerges from the overlap in genetic makeup that interconnects us in the great web of life. Sympathy among everyone else emerges from the impartiality of nature: each of us may find ourselves in straits where a small mercy from another grants a big boost in our own welfare, so we’re better off if we bestow good turns on one another (with no one taking but never giving) than if it’s every person for himself or herself. Evolution thus selects for the moral sentiments: sympathy, trust, gratitude, guilt, shame, forgiveness, and righteous anger. With sympathy installed in our psychological makeup, it can be expanded by reason and experience to encompass all sentient beings.¹³

A different philosophical objection to humanism is that it’s “just utilitarianism”—that a morality based on maximizing human flourishing is the same as a morality that seeks the greatest happiness for the greatest number.¹⁴ (Philosophers often refer to happiness as “utility.”) Anyone who has taken Introduction to Moral Philosophy can rattle off the problems.¹⁵ Should we indulge a Utility Monster who gets more pleasure out of eating people than his victims get out of living? Should we euthanize a few draftees and harvest their organs to save the lives of many more? If townspeople enraged by an unsolved murder threaten a deadly riot, should the sheriff assuage them by framing the town drunk and stringing him up? If a drug could put us into a permanent slumber with sweet dreams, should we take it? Should we set up a chain of warehouses that inexpensively support billions of happy rabbits? These thought experiments make the case for a deontological ethics, composed of rights, duties, and principles that deem certain acts moral or immoral by their very nature. In some versions of deontological morality, the principles come from God.