Are Hippopotamus Ethics Enough?
When we see another being suffer, something happens in us. It is not abstract, not cognitive nor philosophical, it is a visceral feeling which occurs. We feel a discomfort that is not their pain but is definitely related to it. This phenomenon, feeling pain for pain, may be the deepest emotional root of ethics. Before rules, before reason, before social contracts or priests and gods, there has been this simple capacity: the inability to remain emotionally unmoved by another’s suffering once it is perceived and understood.
Perhaps we can even see this mechanism at work in nature. I love watching those videos where hippos intervene when crocodiles attack other animals, often animals the hippo has no reason to care about. A baby gazelle is caught, starts bleating helplessly and shaaaazzaaaaam, a massive hippo charges in, jaws wide open, which sends the crocodile running for cover. This looks as if the hippo “sees” suffering, is affected by it, switches into ethical mode and saves the innocent gazelle.
Of course, the hippo is not a moral philosopher. It is not reasoning about justice or the sanctity of life. It does not think “Every animal life is of equal value, I have a duty to save the gazelle baby!” To be responsible, let me point out that we cannot see into a hippo’s heart, so ethologists have other possible explanations for the hippo behavior, e.g. territorial aggression, misfiring parental instincts, sensitivity to distress signals.
We cannot know for sure, but, personally, I like thinking that we share a moral sentiment with hippos and “hippo ethics” becomes a useable metaphor for a basic emotional response from which a more elaborate ethical system might be derived. The hippo’s response is not ethics as reflection, it is ethics as a type of reflex. An embodied sensitivity to suffering that evolved long before moral language ever existed. This is the raw material of ethics. In humans, it becomes something far more expansive and fragile at the same time.
Pain for Pain as the Basis of Ethics
Plato, through the character Glaucon, famously asks us to imagine the Ring of Gyges: a ring that confers invisibility. If someone could get this ring, they could do anything they wanted to and act unjustly without negative consequence, without punishment or reputational loss. So why wouldn’t they? Wouldn’t justice collapse the moment accountability disappeared?
My answer to Glaucon would not be Kantian and not theological. It is closer to John Locke and, more broadly, to moral sentimentalism. Even if I could not be seen, even if I could not be punished, something would still be there to restrain me: the pain I would feel at causing pain.
When we see someone suffer, we also suffer, not in the same way, not to the same degree, but enough for it to have an effect. This “sympathy,” as Locke and later thinkers like Hume and Adam Smith described it, is not a belief but an emotional response or maybe even emotional resonance. It is deeply embedded in us, likely because it was evolutionarily useful. Groups that contained members sensitive to one another’s pain were more cohesive, more cooperative and more likely to survive.
What I find fascinating is that it seems to cross species too – think of how hard firemen will work to get a little kitten out of a tree. There are instances of chimpanzees or bonobos consoling humans or dogs. Some sanctuary chimpanzees have hugged or groomed humans who are visibly upset. It is more common within species, however. In Uganda, chimpanzees have applied leaves to wounds, helping injured group members, including non‑kin individuals.
Dolphins sometimes help injured members of other species (humans included) to the surface to breathe. A dolphin named Moko, in New Zealand, worked hard to guide a stranded pygmy sperm whale and her calf out of shallow water where they were trapped. Dolphins have also protected swimmers from shark attacks by circling them or attacking predators.

We can’t see into an ant’s heart either, but I found this interesting: in some species like Formica sanguinea and Formica fusca, worker ants have pro-actively rescued trapped individuals (including those of other species of ant) from traps like the kind set by the antlion larvae, risking their own lives. This is called “rescue behavior.”
Ethics does not seem to begin with rules, for us it begins with an emotional response engendered by fellow feeling. Some animals' responses to others' pain hint at deep evolutionary roots for emotional contagion and empathy, which humans might have later elaborated.
My Subway Car Thought Experiment
Imagine this scenario. Let’s say that I am a large man, huge muscles, physically imposing. I am tired and as I step onto a crowded subway car, I see all the seats are full. I notice there’s one shorter, skinny guy sitting down. I could easily grab him and toss him out of his seat and take his place. Why don’t I?
One answer is purely instrumental: I might get arrested or several other short, skinny passengers might band together and teach me a lesson on subway etiquette. This is the answer Glaucon expects, the fear of consequences. (Interestingly, though, it could be argued that the passengers saw someone in pain, felt pain, and gave him justice.) But anyway, Glaucon, like Hobbes, would say that the big man would fear the law or punitive reprisals and leave the smaller guy alone.
But, even if I knew I could get away with it (let’s say all the skinny guys were scared of me), something else is there to stop me. I look at the guy and think, “He looks tired. Poor guy.” I imagine what it would feel like to be roughed up, humiliated, thrown on the dirty floor. The mere anticipation of that pain inside me might be enough to hold me back from doing something my brain suggests but my “heart” disapproves of.
This pain-for-pain principle, deeply embedded in us, prevents countless acts of cruelty every day. It stops us from hurting strangers, exploiting the weak or indulging in any selfish impulse we might otherwise rationalize. It is quiet, untheorized and astonishingly effective…a lot of the time.
The Weakness of Empathy
But here is the problem: this ethical superpower is weak, it has a type of built-in kryptonite.
It is easily overridden, easily distorted and highly selective. The same big man on the subway might suddenly lose all sympathy if the skinny guy is wearing a Boston Red Sox cap and he’s a Yankees fan. If empathy can be shut off by sports branding, it can certainly be shut off by race, ideology or a myriad of factors.
Tribal identity, however trivial, can be enough to wipe out empathy. Once the other person is recategorized as “one of them,” the pain-for-pain mechanism falters. The kryptonite to empathy is: “He’s one of them. It’s OK for him to suffer. In fact, let’s make him suffer. He is not worthy of my empathy.”
This type of demonization is one of the most dangerous features of human psychology since it can and has led to horrific acts of barbarity. The extermination of an indigenous population in North America, the use of people in chattel slavery, dropping two atomic bombs on cities filled with civilians just to see how well the bombs work in vivo etc.
There is another problem. A single crying child moves us more than a thousand anonymous people suffering many miles away from us. A baby gazelle bleating triggers a hippo; news of an immense massacre does not always trigger much emotion; and that brings us to the darker implications.
Demonization, Denial and Sociopathy
In a theater piece I recently saw, a banker who will be a part of an illegal financial scheme to siphon billions of euros from the German government is asked whether his conscience will negatively affect him if he learns that programs for the elderly or children are cut due to his malfeasance. He casually indicates this will not bother him in the slightest. What’s going on here?
He may have already demonized a large part of humanity, consciously or unconsciously redefining them as undeserving, lazy or just abstract human beings. Or he may be a sociopath, genuinely lacking the capacity to feel pain for pain. Or perhaps he lives in denial, emotionally insulating himself so thoroughly that human suffering never becomes vivid enough to register. Recall the saying misattributed to Stalin: One death is a tragedy, a million deaths is a statistic.
In any case, the result is the same: the ethical mechanism never activates. Ethics, when grounded solely in empathy, is fragile. It depends not just on the existence of pain-for-pain, but on whether we allow ourselves to feel it. And modern life offers endless tools for numbing, distancing and rationalizing away the suffering of others.
From Hippos to Humans
The hippo charging a crocodile is a compelling image because it is the embodiment, to us, of ethical action unmediated by anything. Wouldn’t it be nice if that was all we had to do. But the hippo does not generalize its concern. It does not build institutions. It does not worry about unseen gazelles suffering downstream because the hippos over there are corrupt and demand quid pro quo. The fragility of our hippo ethic might demand that we need greater externalized restraint.
Human beings can do all of the above that hippos cannot but only if we buttress our weak empathy with norms, laws and moral reflection — external safeguards. Pain-for-pain may be the emotional foundation of ethics, but it cannot be the whole structure. Left alone, it collapses under tribalism, greed, ideology and scale. And yet, without it, nothing else stands.
This also works in the reverse. Reason without empathy can become cruelty with justification. Rules without feeling become empty, tedious procedures. Even the most elegant moral theory fails if it never connects to the lived reality of suffering.
Are Hippo Ethics Enough?
So are hippo ethics enough? Clearly not. But neither are they dispensable. Feeling pain for pain is not a complete moral system. It is something older and more basic: the spark that makes morality possible at all. It is the reason Glaucon’s ring does not fully corrupt us. The reason most people do not seize power or cause harm whenever they can. The reason a crowded subway does not become a battlefield.
It is weak, biased and easily manipulated, but it is real. And perhaps the task of ethics is not to replace this fragile superpower, but to protect it, expand it and prevent us from talking ourselves out of feeling it.

Empathy alone cannot overcome demonization. Deliberate rules, protection of rights and cognitive safeguards can. The only reliable counterpunch is externalized restraint: rule-based ethics that protect even those we might see as enemies; institutional safeguards such as laws, courts and accountability; deliberate re-categorization of others as human or civilian rather than “enemy.” Unfortunately, humans will probably not stop demonizing because they realize it is wrong, they will stop because there are more “good” people than “bad” and we can create systems to prevent demonization from causing harm.
In that sense, the hippo is not a moral hero. The hippo is a reminder of where morality begins, and of how much work remains to make it effectively humane.
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