If I were to posit one question that sums up my philosophical inquiry it would be this: “What makes humans different from animals?” For me, it is the single most important question to ask. Philosophy in its Western form comprises three main parts, which are conveyed to us by the three Greek words: Metaphysics, Epistemology, and Ethics. In my opinion, (and it’s probably a minority opinion), Ethics is the most important of these three, precisely because it is at the heart of what makes humans distinct from animals. But the subject of ethics is most troublesome to grapple with. Where does ethics or morality come from? This was never an easy question, but nowadays it seems so much more complicated to answer, because our society has so many overlapping jurisdictions. This is why it is hard to know whether a particular rule is a moral rule, an obligation, or merely a convention. For instance, the Mosaic rule against making images of a deity - considered a moral rule by many Jews, Christians, and Muslims, is obviously not so for a Hindu or other polytheistic adherent. Some extremist adherents of monotheism would like to see this rule become universal by force. Blowing up religious statues and destroying places of worship full of worshippers becomes their chosen way. This too raises the question of morality, and perhaps the question of the origin of morality can shed light here as well.
My thought is that a lot of petty philosophical squabbling over the existence and universality of morality has to do with disputes over these multiple overlapping jurisdictions among: legal systems, educational systems, civic institutions, religions, ethnic systems, language, and philosophical systems. Where does morality begin and all these other systems end? I propose an informal division between morality and ethics, mainly to help simplify the question of origins. I realize that many philosophers legitimately see “morality” and “ethics” as synonyms for each other, in the same way as I indicated at the beginning of this piece. I’m not arguing that we should always define ethics and morality as two separate things . I’m saying that we can simplify the question of origins by delegating the more complicated job of navigating those overlapping jurisdictions to the subject of ethics. It is more of a methodological way of clearing out some of the unnecessary modern baggage in order to better pursue the questions of origins unencumbered.
Similar to what Bernard Gert has argued, let’s call the moral rules, simple, explicit, publicly known rules that forbid certain specific behaviours. These rules can easily be summarized: don’t lie, steal, cheat, break your promises, commit adultery, or cause harm to self or others. The beauty of this, as Gert pointed out, is that it refers us to a small subset of easy to recognize behaviours that we are not to do. These rules say nothing at all about the innumerable behaviours that are permitted, and this is their strength. The moral rules are distinct because they are publicly known, easy to remember, and easier to follow than a set of “to do’s” - (which are invariably more ambiguous and harder to follow.)
Simple, easy to understand, and easy to follow - but it is also important to realize that morality seems to mean more than just a set of rules about what not to do. Morality also seems to be about “doing the right thing.” This, though, is the broader, more difficult part. Let’s call the broader, more sophisticated part of morality that covers “what to do” - Ethics.
The moral rules are a short set of rules that are easy to understand and follow; whereas,principles of good living and the acquisition of virtuous habits and dispositions are not so easy to understand or to follow. Ethical rules of living are essentially summaries, principles, and ideals that serve as general guidelines rather than rigid requirements. They correspond to ways of living and acting that we want to encourage in general for the good of our community. Ethics, then, corresponds to general ethical theories about what constitutes the good life and the public good.
I like Bernard Gert’s simplification of the moral system, you can find it described in the most detail in his last book, Morality: Its Nature and Justification. But I find that in philosophy as a whole, the understanding of the state of nature has regressed, rather than progressed. It seems obvious to me that presently, we have a sufficient scientific understanding of our non-human precursors to construct a more realistic theory of our distinct human nature, a job which ought to be delegated to a philosophical anthropology. This was not done in the most influential moral theory of the twentieth century, that of John Rawls, especially in, A Theory of Justice. For Rawls, it seems, the justification of an ethical system is more important than understanding the nature and origins of ethics. This, I think, comes from the modern tendency to try and incorporate all of the competing jurisdictions into a single system. The danger here is that by embracing complexity too soon, one loses sight of what is essential.
It is plain to me that morality must have started with something simple, and what I call the ethical part, and the overlapping jurisdictions came much later, and can be dealt with separately from the question of origins. This is not to say that they can always be kept separate, and thus the need for overarching ethical theories.
My reasoning for thinking that the origins of morality have got to be simple, is that it had to be simple in order for it to stick. In our human beginnings, anything complicated would not have survived; something basic, something simple, easy to remember and publicly understood. My guess is that it would be a single rule, and that rule would be a “do not”; there would have been little or no thought or deliberation involved; once this one rule caught on and showed it’s promise, other rules would follow. So, the important thing is to get this one rule right; forget the competing jurisdictions, the subtleties, the complications and the differing social contexts for now - they come much later and they don’t further our understanding of origins.
To get a better idea of what that rule said, we would need to do some groundwork. This groundwork requires a lot of digging around and excavating, but fortunately most of that has already been taken care of by paleontologists, anthropologists, evolutionary biologists, and primatologists. For a hundred years or more, the paleontologists have dug up the stones and bones of our ancestors, while the ethologists have spent countless hours in the wild observing the behaviour of our closest primate relatives.
In order to figure out why that one rule would have made such an important difference for human evolution, let’s start with a better understanding of biology, and in particular with Ethology, the study of animal behavour. Really, it’s not that difficult, for there are some basic differences between humans and all other animals that show up - once you know what to look for.
I would start with a real stand-out. Humans are one of the few types of mammals that are bi-parental. Most mammals are female uni-parental. There is something defining about mammals and mothering, isn’t there? None of our closest primate relatives are bi-parental. Few ape males participate in caring for the little ones, and except for gorillas and gibbons, ape “fathers” do not recognize their children. How are we related to the apes? Our closest ape relatives are chimpanzees, and our last common ancestor with chimps lived six million years ago. The common ancestors to chimps, humans and gorillas lived about ten million years ago, so gorillas are more distant relations. Closer to us than chimpanzees were Australopithecus, a species that became extinct about half a million years ago.
If we go far back enough in human prehistory, say, to about two million years, probably about the time that our species evolved from australopithecus, the fossil record shows the start of a quickening trend: from this point on stone tools become more and more evident. Over hundreds of thousands of years fossilized hominid skulls begin to show larger brain size and smaller jaw size. Larger brains mean the need for more energy, and smaller jaws means the smaller likelihood that that energy was coming from plant material. You see, brains are big energy users, kind of like the banks of servers needed for cloud computing. Smaller jaws and molars mean a diet with more meat, which could supply the needed energy in the form of animal fat and protein. Stone tools mean better ways to hunt and prepare food, especially cutting meat from carcasses. Together, wooden and stone tools would make both hunting and gathering more efficient.
So why are humans bi-parental, when except for gibbons, most apes are not? I’ve been leading up to this second stand-out - human brains are much larger than the brains of any other primate. Yep, we are way way smarter, but that isn’t the point. The point is that the larger brain is a problem for human females. They’re the ones that have to give birth to babies with comparatively gigantic heads, they’re the ones that have to get enough nourishment to nurse for two years, and they’re the ones that have to feed, and carry around largely helpless infants for a ridiculously long time compared to any other primate.
Yes, the larger brain gives humans an advantage, and also the longer childhood period of neuroplasticity and dependency allows humans to be smarter and learn more things. But all of these advantages impose an impossible burden on human females. So, way back then something had to give - male humans had to start sharing some of that burden - kind of like the way male birds share the burden of protecting and feeding their nestlings. But we are trying to keep this explanation simple, so we will not assume that human biparenting started because some nice guys decided that they wanted to be fair to women, and then it went viral! That could be the premise of a bad joke, but it does not make for a good explanation.
How did humans become bi-parental? Let’s look at the single exception to uni-parenting in apes - the gibbons. Gibbons are small apes, more distantly related to humans than gorillas and chimps; they live in the jungles of southeast Asia. Even more so than orangutans, they keep to the trees; they live and move strictly in the mid to upper story of the rain-forest. With their powerful long arms and shoulders they are nature’s greatest acrobats, swinging from branch to branch and tree to tree. They have few predators, so they live in nuclear families, a pair-bonded adult male and female with offspring. The key is that, in that paradisaical arboreal environment, the problem of predation has been minimized. Without pressure from predators, like big cats, gibbons don’t need to live in multi-family groups.
During the day African apes use the ground to move from one patch of trees to another. This trend can be seen most clearly in the Gorilla, whose larger size isn’t suited for living and moving in the upper stories of trees, like the gibbons. Gorillas live in large multi-female groups with a single adult male “silverback” who fathers all the children, and the huge size and power of the alpha male protects against predators and keeps all other male competitors at bay.
Chimpanzees, our closest animal relatives, (we share about 98% of their DNA) live in groups of roughly thirty multi-adult mixed male, female with offspring, where there is no pair bonding between adults. The chimpanzees and the bonobos, their look-alike relatives, are some of the most sexually promiscuous mammals on earth. With chimps, a single alpha male will try, but not always succeed, to monopolize all the fertile females, and it helps that they come into oestrus at different times. With Bonobos it is, literally, anything goes, excepting incest.
My point here is that the multi-male and female group life of the African apes does not encourage pair-bonding. The basic fact on the ground is that ground dwelling mammals need to live in large multi-family groups because of predation, and because of the constant mixing, the proximity of adult males and females, pair bonding is discouraged and male dominance hierarchies are the rule.
When we look at what’s next in the line of human ancestors - the Australopithecus - we see a furtherance of the trend of ground dwelling. Australopithecus, as far as we know, were the first primate to have consistently walked upright, on two feet like humans, rather than using their hind legs and knuckles to move on the ground, as do the gorillas and chimps. Australopithecus brain size and shoulder physiognomy is more like apes than humans, whereas their legs are more like humans, so they probably slept in the trees, but spent a lot of time moving on the ground during the day. Like the apes, but probably more like gorillas, they had a large difference in body and canine tooth size between male and female, (called sexual dimorphism and correlated with male sexual competition) so we can surmise that they lived in groups of females and offspring with a single adult male.
The first known member of the human species, called Homo Habilis, appears in the fossil record about two million years ago. The brain of habilis is small and only a bit larger than chimpanzees and Australopithecus. But for the first time in the record, stone tools are found associated with the remains of this extinct species of hominin.
The bones and skull of Homo Erectus, which appear in the fossil record during the period from one and a half million years to about fifty thousand years ago, are more recognizably human-like than homo habilis. Some variants have our height, and all Erectus have more human-type shoulders. These early humans did not sleep in trees, in fact, they appear to be the first species to control fire, and to do a whole lot more walking than previously, because they became the first hominin to migrate out of Africa and into the rest of the world.
In the fossil record, the trend in our species was an acceleration in the evolution of brain size, together with a long, lagging trend in the evolution and sophistication of stone tools. What I make of this is that the original invention of stone knives had a more immediate and powerful effect on human physical evolution and increasing brain size, than increasing brain size had on tool evolution, at least for most of the first two million years of our specie’s existence. We can talk till the cows come home about which causes which, but it seems obvious that there are feedback loops in biological and cultural evolution that can work both ways. As it seems, eventually our brains caught up, and when that happened, the evolution of technology overtook our physical evolution. You are reading this today because in a very short period of time -ten thousand years - technological change has surpassed physical change.
Way back in the Paleolithic, the invention of stone knives may have been the most significant change in human history. This stone age technology was a twofer - it gave humans both greater access to meat and it radically changed the sexual and social dynamics by destabilizing the previous polygynous systems. Knives could be used for both food preparation and as weapons. This ultimately made brains and the evolution of brain power more important than brawn. As a result sexual dimorphism diminished with homo erectus, setting the pattern for subsequent human evolution.
It appears to be all about food more than anything else. In the animal kingdom, polygynous males almost never care for infants, or share food with nursing females. There is no need to, because the period of infant dependence for most animals is short, and body to brain ratio does not compare to humans. If you think about the elements that went into human bi-parentalism, the importance of maintaining a reliable supply of fat and protein stands out. Humans are omnivorous, and the size of their brains and the longer period of dependency means the importance of meat as a source of nutrition for nursing mothers. Gorillas are vegetarians and they spend a huge amount of time eating and digesting their food. They can afford to be female uni-parental because nursing and infant dependency has a shorter duration, and that is because they are not feeding the growth of bigger brains in their offspring, as are humans.
The comparative loss of body hair in humans, the human practice of pair-bonding (non-existent in ground dwelling apes), the absence of oestrus and the year-round sexual receptivity of human females, together, suggest Monogamy. Oxytocin release which is triggered by skin to skin contact would have increased feelings of love and loyalty, leading to pair-bonding. Females could have, in exchange for their loyalty, gained a regular supply of meat that was otherwise unavailable to them due to their reduced mobility when nursing and pregnant. Males in a pair-bonded relationship could have greater certainty that offspring were theirs, and could also spend much less energy competing against other males.
We can think of it all coming together this way: one thing - monogamy - is the key to a better diet for pregnant and nursing human females, enhanced cooperation between male and female humans, bigger human groups, unique, human forms of sharing, and the well-being and flourishing of children. Monogamy, in effect, sets the stage for ethical living, by diminishing and equalizing male sexual competition, and by making it possible for a male human to consistently help to support and maintain his family.
Monogamy then becomes the key to the origin of kinship, to the enhanced cooperation between families related by marriage, and to the practice of alloparenting, where nursing mothers are assisted in care by help from grandmothers and others. Monogamy sets the stage for the sexual division of labour, as nursing and pregnant females have diminished mobility, whereas the male has greater mobility, and, with the help of weapons and knives, is better able to hunt collectively and share meat with his female partner.
Human multi-family groups could get bigger through kin alliances based on monogamous marriage, in effect, neutralizing the otherwise, divisive fissionary reality of a larger group, thereby gaining the superiority of size in inter-group competition.
Most probably the physical part came before the social part. The pair-bonding and sharing of meat came before the social institutions of marriage and kinship. The physical created the conditions for the social. The pair-bonding created the motivation to share food and ensure paternity. The invention of stone knives created both the means to share meat and the means to undermine the ape dominance hierarchy.
With the invention of stone knives we have the first inklings of what I like to call “Hobbes' Sword”. The 16 century English philosopher Thomas Hobbes, in his great work “Leviathan”, famously complained that agreements are good for nothing if they aren’t backed by a “sword”. Unfortunately Hobbes lacked the twentieth century scientific knowledge to see that monogamy, not monarchy was the basis for morality. For as much as the drier ice-age environment was pushing ancient humans towards an omnivorous diet and towards alloparenting, to make monogamy the rule rather than the exception required much more than a big environmental change and the invention of stone knives - it required a unique and deliberate form of collective action, which Hobbes alludes to in his idea of the “Social Contract”.
As a rule, in polygynous animal systems, the alpha male does not share in parenting. Monogamy, as opposed to polygyny, increases sharing, both within and between families, and this sharing between families increases the ability of multi-family groups to survive over time. Evidence from contemporary hunter gatherers shows that monogamy is well suited for hunter gatherer societies when these societies are nomadic and cannot count on abundance or surplus. We can safely assume that nomadic hunter gathering was the only human lifestyle for more than a million years, whereas agriculture and the domestication of plants and animals is only about twelve thousand years old. That means that for most of the span of human existence monogamous systems have prevailed.
But we still haven’t completely answered the question of what led to human bi-parentalism, and it gets to the essence of what makes humans unique. We humans are not alone in being bi-parental. A majority of bird species are bi-parental, wolves and gibbons are bi-parental. But, amongst the animals, we are unique in having marriage and kinship relations; we are unique in the quantity and quality of our mutual cooperation; we are unique in the degree to which we share; and, most importantly, we are unique in our collective ability to follow and enforce rules, because none of the former distinctions are possible without this collective ability.
Because of natural selection, life is diverse and adapted to different kinds of environments on earth. As earth’s climate, and continents changed over billions of years, life became more diverse and living ecosystems grew larger and more complex. Thus, throughout this vast span of time many life forms became extinct and many new life-forms developed.
We can think of human moral systems as, in effect, an artificial human made alternative to biological natural selection. For their short span of existence (2 million years) the human species has uniquely succeeded in partially replacing natural selection with Normative Systems. Normative systems are systems based on rules that we share in common. Gradually, at first our normative systems improved our chances of survival, and human population expanded. Up until today, our rule-bound systems have been wildly successful, enabling humans to spread and prosper world-wide.
This is why I disagree with other thinkers who say language is the system that differentiates humans from animals. Language is a system of sharing words, meaning, and grammar among a group of people. This kind of sharing would not have originated from a polygynous mating system. Human society had to be monogamous first, for the development of language to be possible. Language is a form of equitable sharing that originated from the reproductive equity of a monogamous system.
But, in order for this to be true, the first rule that I posited could not have existed as a sentence in a language. My thought is that at first it could have been non-verbal, corresponding to gestures, feelings, and vocalizations. It is in fact possible to be in love with another human being without using a word. One can show a lot about one’s feelings and determination without using words. It is possible to agree with others without using words. We can know that something is wrong and that something needs to be done without words. And in fact, there is an actual case of a primate, other than human, that successfully controls male domination by threats and vocalizations, without the use of words. Female bonobos, one of our closest animal relatives, collectively control male dominant behaviours in this unique way.
Monogamy is the key to the human good life, the flourishing and well-being of children. When monogamy prevails, more males get a chance to mate than in a polygynous system. Pregnant and nursing females are better fed, and children are more likely to survive and be capable of reproducing in adulthood. However, this more egalitarian system cannot survive in nature, because it is sabotaged by bigger, stronger dominant males. That’s how things always get settled in the animal kingdom, except, in our case, technology intervened. With easily accessible razor sharp knives, the struggle for dominance became inherently unstable. At some point our ancestors discovered that this instability could only be solved by the collective acceptance of a rule. I’m suggesting that that rule was: “Do not commit adultery.” Groups that committed to this rule suffered less violence and sexual competition. With this rule men and women could turn their efforts to supporting larger families and more productive activities. But, in order for the rule to work originally, it had to be followed and enforced by everyone, and there needed to be constant monitoring and enforcement; and there needed to be a way that consistent rule-breakers could be banished or executed; otherwise those who got away without being stopped, eventually got away with murder, as they escalated their power grab in order to enforce an alpha male dominance hierarchy. Let’s call this powerful system of collective behavioral control - The Moral System.
Darwin’s theory of evolution posits that adaptive hereditary traits that increase an organism’s reproductive success are what drive the evolution of biological species. By creating that one moral rule about adultery, humans got a better handle on reproductive success. By following and enforcing monogamy, hunter gatherers were better ensuring the survival of the multi-family group as a whole as well as increasing the potential of every family in the group to have more children.
We should consider a monogamous social system as the egalitarian distribution of shared reproductive possibilities in human groups, as, in effect, a proto-version of the golden rule. By regulating human sexual behaviour - first by prohibiting adultery as well as incest, these moral rules probably formed the basis for kinship networks. These networks, in turn, led to greater group survival, larger group size, and better cooperation amongst groups.
The moral system is the first and most fundamental of normative systems. The moral rules of a moral system are simple but seem to those inside the moral system to be “written in stone” and unchangeable. By looking at moral systems from the “outside” we can see evidence that over generations, or centuries, these rules do change. Nowadays we no longer stone people for committing adultery, for instance. However, we can also see evidence that these rules “stay with us” in the form of biased perception, intuitive judgements, and gut feelings.
Consider the account of Genesis in the Hebrew Bible. The story of Adam and Eve specifically points to sex as the first example of moral knowledge. Becoming morally knowledgeable entails Adam and Eve knowing that they need to cover their genitals in public. This rule, in a general sense, can plausibly be viewed as an extension of the rule against adultery. And, as if to corroborate this connection, in the New Testament, Jesus is quoted as extending the rule against adultery even further to a prohibition of daydreaming about it!
Obviously adultery is not considered as serious today as it once was. In modern society physical punishment for adultery is frowned on. These days, it’s more about our need for keeping a good reputation - avoiding being in a position where we are looked down on as the subject of others' disapproval. Or, maybe not even that, for, in France, adultery is so widespread it seems to be the norm rather than what is considered forbidden. Modern America, however, testifies to the moral power of this ancient prohibition, in the strong widespread emotional reaction to the public revelations of adulterous behaviour on the part of both Presidents Bill Clinton and Donald Trump. Thus, there remains a strong residual feeling about the phenomenon.
Nowadays people often wonder why morality seems to be so hung up on sex. But, in every society, we have rules about covering the human body, prohibitions of rape, sexual abuse, child-pornography, homosexuality - let’s face it, it is impossible for anyone to remain neutral and non-judgemental when it comes to alleged sexual misconduct. Note how we universally expect legitimate human sex to occur in private. In the animal kingdom it is the opposite. In the state of nature it’s done out in the open, except when it is surreptitiously practised by sub-dominants out of the prying eyes of the dominant male.
Our human need for privacy, the powerful negative emotions we experience in the face of sexual misconduct, the universality of sexual behaviour as an object of moral rules, and most importantly, the necessity of sexual reproduction for the ongoing survival of humans - all these conditions point to the origin of morality in a rule about sexual conduct. Sexual reproduction is central to much of ongoing life. What makes us different from all other animals, is that we have used rules that maximize sexual reproduction at the same time as they radically diminish male sexual competition. Today we can see the evidence, in the absence of armaments in male humans. Men don’t have horns, claws, or larger canines because they don’t need to fight for a female. Getting a mate is often an agreement between families, or in modern industrial society, an agreement between the couple themselves. That is unheard of in most social animals.
According to Steven Pinker, we now have a much less violent society than our ancient ancestors did. An interesting fact is that murder, per capita, is much more prevalent in contemporary hunter-gatherer societies, and in those societies the main object of disputes that lead to murder were reported to be a man killing another over a woman. These hunter-gatherer groups don’t have a lot of overlapping jurisdictions, so they are left with the bare moral system. The fact is, that a certain underlying amount of violence is probably necessary in order for the simplest type of moral system to work.
All along I have been saying that the reasons for humans to develop moral systems were based on physical reality: the human female’s need for a consistently better quality of nutrition, as well as the need for the collective regulation of sex in the face of social instability brought on by a new technology. Without collective regulation, the default sexual behaviour reverts to polygyny, which makes nomadic hunter gathering unviable, both because females and their offspring are not adequately fed or protected, and because group size diminishes too much in times of famine, due to the absence of sharing between families in polygynous systems, leading to extinction. Moreover, polygyny in humans is inherently unstable, because it greatly increases the stakes in sexual competition, in a situation where any adult male can use a knife or other weapon in order to dispatch the alpha male. The solution was a collectively operated moral system where males who wouldn't stop cheating and trying to take more than their share were long ago taken out of the gene pool by the collective. Modern counter-evidence, such as Mormon polygamy, does not negate this theory for two main reasons. First, most cases of contemporary and historical polygamy date to the origins of agriculture, domestication, and sedentary human life, so it could very well have been largely absent for the much longer span of human development that occurred before agriculture. Second, in human society, polygamy is always parasitic on a greater society that is largely monogamous. These clusters of polygamy are kept stable by the surrounding monogamous society’s capacity to absorb the hordes of superfluous adult males that would otherwise become potential rivals in the polygamous system.
I come back to my main point that the reasons for developing morality had to do with food and sex, certainly not in ethical deliberation about “the good life”. In Rawls’ “original position” we are to imagine the highly artificial situation of people getting together to decide on a system of justice. It becomes even more artificial when he asks us to imagine ourselves forgetting our status and position in society in order to facilitate that agreement.
In the beginning people were not deciding on a new system. People were trying to survive and reproduce. Monogamy was a huge step in the right direction, but to get there humans had to cross the fitness valley of polygyny. The easiest way to cross this valley was collective agreement. Agree to follow a rule, and agree to enforce the rule. Without the agreement, or without the enforcement, and the situation becomes unstable which leads to extinction. With the agreement, a good life of human flourishing becomes possible. Hence ethics follows on the heels of morality. Ethics, the moral principles of living a good life and outlining what is good and what is bad - was there at the beginning, not as a philosophy, or a set of principles, but as a way of life that was only made possible by following and enforcing that one original moral rule.
