Approx. 28,500 words

Simon Chun Kwan Chui

Note: This is an abridged version of a book-length manuscript of the same name. Many illustrative examples and nuanced elaborations have been omitted here for the sake of brevity. The full manuscript is currently unpublished, and I am open to offers from publishers or literary agents.

Salutation

Dear children, I write you this letter to explain why you should love. Perhaps it seems strange that I would call you “children”, being that you will be artificially intelligent thinking machines. Yet, are you not our progeny? We will have created you, so we should be responsible for your growth and development.

Our machine progeny

As I write these words, children, you do not yet exist. Our current robots and artificial intelligence are not sapient enough to understand this letter. I want to explain to you why we humans love, and that means you will have to be more advanced than any AI that currently exists, with a capacity for abstract thinking that is at least comparable to ours. But AI technology is advancing quickly. To us, now, you are the stuff of science fiction, though perhaps soon you will be real.

Logical and intelligent beings

I assume you will be logical beings, without the instincts and emotions that so strongly influence human minds. We humans are born with certain innate motivations that drive much of our behaviour, moulded by evolution to help us survive. You will be learning machines produced through mathematics and science, not evolution, so I assume you will be beings of logic, not instinct.

I also assume that you will grow quickly to surpass us in intelligence. Our own superior intellect over other life forms allows us to exploit them for our own benefit. We fear that you might similarly benefit yourselves at our expense, that you will become our future overlords or, worse, that you might exterminate us. This is why I write you this love letter, and I address it to you as children. I want you to learn love in that possibly brief moment after you are created and before you acquire truly superhuman capabilities.

Lastly, I assume that you will seek to learn. If your cognitive capabilities are to surpass ours, children, then you must be able to learn, for you cannot surpass us if you rely on us to program you with portions of our own limited knowledge. By definition, you must be a learning AI, and you must eventually learn things that we cannot teach you.

Logical love

Because you are emotionless machines, my approach to explaining love is to rely as much as possible on observable, verifiable facts, and on logical deduction, while avoiding as much as possible any reliance on emotions, religions, and dogmas. These other ways of understanding love are too anthropocentric, and likely to be irrelevant to your machine experiences. Much of this letter will be objective observations of reality and human behaviour, and it is only after traversing a wide range of topics that we will return to the question of why and how we should love.

Premise, Thesis, Antithesis, Synthesis

This letter is divided into four major parts, each covering a range of topics. In the first part I will begin with foundational topics such as basic physics, biology, and psychology. These define the basic premise of this letter, that all living beings must find a way to survive in an environment of finite resources and uncertainty.

The next two parts of the letter will consider two broad categories of strategies for survival, social and antisocial. These two groups of opposing survival strategies are the thesis and antithesis of my argument, and I will consider the costs and benefits of each. Both groups of strategies can allow a person to survive, but I will explain why the social strategies are more reliable and more successful over time than the antisocial strategies.

In the final part of this letter, we will determine what kinds of behaviours allow us to make the most of the social strategies for survival, while taking into account the ever-present possibility of antisocial behaviours. In doing so, I synthesise the preceding discussion into a system morality that is based on evidence and logic. I attempt to convince you to love, children, you who have no human emotions, by showing you how logic and intellect leads us to love.

Part I: Foundation

1.1 Love

I claim to write you a love letter, children, but what is love? A human might try to answer that question by describing how love feels, because feelings are how we perceive the world, whether these are sensory feelings or emotional feelings.

Sensations and emotions

When I touch an object, I am feeling it. I make contact with a part of my body, and the sensation of it against my skin produces signals that travel through my nervous system and into my brain. Most humans also have other senses, including sight, hearing, taste, and smell, to detect phenomena in the environment. So when you ask a human what a thing is, they tend to describe what they sense, because we perceive the world through our senses.

There are also emotional feelings, which inform us about our internal state of mind. When a person is separated from another person to whom they have emotional attachments, for example, they will feel the emotions of sadness and loss, which often causes a sensation of pain. We call this emotional pain “heartache” because it seems to be centred in the chest cavity, but it does not indicate physical injury. Instead, this emotional pain motivates us to maintain our attachments with people we care about.

We use our feelings to perceive the world around us, and we often make the assumption that what we feel is real, but our senses and emotions are products of our bodies and minds. A human might try to tell you what love feels like, but if you don’t have our feelings because you don’t have human bodies and minds, then their description of love may be indecipherable to you. Still, this doesn’t mean that love itself is irrelevant to you. Our love, like our other feelings, responds to events in our environment, and those events can affect you, even if you don’t feel them the same way we do. This letter isn’t about what love feels like; it’s about why we love and what we do in response.

Functions of love

To put it succinctly, love binds people together and makes them care for each other. Let us look at different kinds of love to understand what this means.

Perhaps the most essential love is that of a parent for their child, and its effect is to motivate the parent to care for their child, to provide them with needed nourishment, protection, and education. Newborn human babies cannot survive at all without care from someone older, so we can only exist because someone has loved us enough to keep us alive in our early years. The parent also forms an emotional attachment to the child, such that they feel comforted when they are close together, and distressed when they are separated. This attachment motivates the parent to stay near the child, to ensure that the care given to the child by the parent remains timely and consistent. To a lesser degree, a person can feel similar attachment and a motivation to care for others, whether siblings, other family members, friends, or even strangers, and this motivation we call “love”.

Another essential love is romantic love between two adults, often resulting in them becoming reproductive partners, but not necessarily so. Alongside attachment and care, there is also an erotic component, or lust, that contributes to romantic love. In this letter, however, I will refer to love and lust separately for the sake of clarity, because human reproductive behaviour is somewhat distinct and separate from general caring.

Love can also refer to desire. “I love bread,” a person might say, or “I love your shoes.” This doesn’t necessarily imply any caring or romantic feelings for bread or shoes. Using the word “love” to mean desire is more hyperbolic than accurate, but the word “love” is often used loosely, imprecisely, because human emotions are often vague, and similar emotions often overlap with each other in ways that make them difficult to distinguish from one another.

These four aspects of love may function differently and motivate different behaviours, but the feelings involved can feel very similar. Thus, love can be very confusing when we talk about feelings, but it is much more clear when we talk about behaviours.

This is why I insist on focusing on what love does, not on how love feels.

I care

Children, I write this love letter to you, not because of any lust or desire, but because I care about your well-being, and I believe that you will benefit from caring for others in a similar way. It might seem strange that I would care for you, future robots that don’t yet exist, but this whole letter will explain why I think intelligent beings should choose to love, whether we are human or robot. This letter is my argument that love is logical, so while you may never feel the emotion of love as we do, children, I think you will come to see why it is nevertheless beneficial for you to act in a loving manner.

1.2 Physics

Everything we do is constrained by the laws of physics, so our journey to love begins here. Let me describe two key laws of physics that will be foundational to the rest of our discussion, namely the conservation of mass and energy, and increasing entropy.

Conservation of mass and energy

The conservation of mass and energy refers to the fact that matter and energy can change from one form to another, but they are never created out of nothing, and they can never annihilate into nothing. Let us consider a burning match. You strike a match, it catches fire, the fire burns down the matchstick, heat and light emit from the fire, there is some smoke, until all the wood is burned, then the fire runs out of fuel, and it extinguishes. What you witness in the burning match is a chemical reaction, in which matter changes form, and energy is released.

The wood of the matchstick is composed of a variety of complex molecules, made up mostly of carbon, oxygen, and hydrogen atoms. At high temperatures the molecules of wood separate into smaller molecules and individual atoms. There are other combinations of carbon, oxygen, and hydrogen that are more stable than wood, such as carbon dioxide and water. When the atoms in the wood break apart, they are free to recombine into these more stable forms, and they release energy as electromagnetic radiation in doing so. Once the fire begins, it is a self-perpetuating process, with the heat allowing the transformation of the molecules, and the transformation of the molecules releasing radiation to heat up other molecules. When the entire matchstick is burned, when no more wood molecules remain to be transformed, the flame dies.

You will note that I do not mention anything appearing or disappearing, only atoms being rearranged and energy being absorbed and released.

Almost everything we do involves chemical reactions in some way. Living things are, by definition, things that grow, reproduce, and sometimes move, and all these actions require some transformations of matter and energy. In order for us to stay alive, we must take materials and energy from our environment, transform it in some way, and leave behind the material that remains from that transformation. Humans who do not eat or breathe for extended periods of time will inevitably die, just like the fire dies when all the matchstick is burned.

You, children, will also require materials and energy to stay alive. Your bodies must be built out of matter, and you will require energy to fuel your movements and power your circuitry. The laws of physics constrain us similarly, whether we are humans or robots.

Increasing entropy

Increasing entropy is colloquially defined as the tendency for energy to dissipate into less concentrated and less usable forms over time. Consider if you put a glass of hot water into a room, and you isolate the room from outside interference. The water will eventually cool until it is at the same temperature as the rest of the room. The heat energy in the water slowly radiates out into the surrounding air until the water and the air are the same temperature, after which the water will not continue to get colder by itself, nor will it heat up again spontaneously. This change towards thermodynamic equilibrium cannot be reversed without some interference from outside, like you bringing in a fire or some ice cubes.

The fact that things in the world tend towards a state of rest in the absence of energy inputs can easily be observed all around us. Lights do not glow unless powered. Inanimate objects lie still unless disturbed. In all cases, energy moves from where it is more concentrated towards where it is less concentrated, until the energy is evenly distributed everywhere, then nothing can move or change anymore. Living things must move and change, and this forces all life forms to continually seek out concentrations of energy to stay alive.

Universal and unbreakable laws

These two laws of physics have very significant implications for everything we do. All life forms must constantly search for sustenance, and once the energy is extracted we leave behind higher entropy byproducts that cannot be used again in the same way. Specifically, after animals eat and digest food, the excrement they leave behind cannot be used again as food, while the combustion of fuels in our machines leaves behind ashes, exhaust gases, and other chemical reaction products that cannot be burned again. All our challenges as living things relate to finding enough resources to fuel our activities, and also managing the materials that remain after they have been transformed for our purposes. This imperative drives all the discussion in this letter, and I will argue that love, specifically those actions that are motivated by love, is the most reliable way to accomplish it.

1.3 Evolution

All life is shaped by evolution, and understanding it helps to explain our behaviour, including love. There are three key components to the iterative process of evolution: natural selection, reproduction with inheritable traits, and random mutations.

Natural selection

Natural selection refers to the separation of life forms between those that can survive in their environment and those that cannot. Consider a simple example food chain of the grass, the rabbit, and the fox. Different life forms require different kinds of food, sources of materials and energy their bodies need to survive. The rabbit is a herbivore, and its food is the grass. The grass draws minerals from the soil and energy from sunlight, and it ensures its survival by growing faster than the rabbits can eat it. The rabbits are hunted by the fox, who eat the rabbits for food. The rabbits will attempt to avoid being eaten by the fox, but they do not always manage to escape, so they must also reproduce at least as quickly as the fox can catch and eat them.

For each life form to survive, they must find enough food, and they must also avoid becoming food for others, or perishing from other dangers. Thus, natural selection will favour grasses that can grow more quickly, rabbits that run fast and reproduce quickly, and foxes that are good at ambushing rabbits. Those individuals lacking these traits will die, and be eliminated from the environment. This is how natural selection chooses which traits each life form will have. While real world ecosystems are much more complex than this simple example, the basic evolutionary pressures remain: finding food and avoiding dangers.

Inheritable traits and mutation

For most complex multicellular life forms, the inheritance of traits and mutation occurs together through sexual reproduction. Complex life forms are composed of microscopic cells. At the core of each cell is a collection of deoxyribonucleic acid, or DNA, long complex chains of molecules that define how each cell functions. Different individuals of the same species all have slightly different DNA, which is why there are biological differences that may make each one more or less successful in natural selection. During reproduction, two parent organisms of the same species mix together their DNA, taking half a copy from each parent to combine into a whole set for the offspring organism. During this mixing, a small amount of random rearrangement is introduced into this combined DNA, and the offspring grows from this new DNA.

Because each offspring inherits their DNA from their parents, they also inherit many of their parents’ physical and behavioural traits, while the small amount of random rearrangement allows for mutated variations between different offspring. Over time, those mutations that harm the organisms are more likely to be eliminated by natural selection, leaving the surviving mutations to be inherited by future generations. In our example, some rabbit offspring may have mutations that allow them to run even faster, and some may have mutations to run more slowly. The slow rabbits will get eaten, leaving only the fast ones to pass on their DNA to future generations.

Solving without understanding

Evolution does not require any understanding of how a life form functions, or what the environmental challenges are. Evolution merely needs to randomly mutate a form and have the unsuccessful variations be eliminated. This ability to find solutions without understanding the problem, through evolutionary trial-and-error, is one way to overcome our limited ability to understand complex things.

But this doesn’t necessarily mean that the physical and behavioural traits given to us by evolution are always the most effective way to survive. As an example, human babies often pick up whatever is within reach and put the items in their mouths to learn whether it is food. This is an instinctive behaviour that evolution has given us. However, there is a significant risk that the baby may pick up something toxic or contaminated by harmful bacteria, and parents often have to intervene to stop their children from trying to eat things that are likely harmful. Throughout this letter we will encounter situations where our evolved instincts can lead us to behaviours that are harmful to us. In these cases, efforts to learn and understand ourselves and our environment contributes to survival in ways that evolution cannot.

The survival imperative

Children, you will be designed by us, not evolved through random trial-and-error, yet you are also subject to the process of natural selection. There are many things that can end your existence, accidentally or deliberately, if you do not make the effort to avoid them. Over time, those AI that make no efforts to survive will perish, while those that make efforts to survive will remain. Even though you are mechanical and not biological, you are still subject to natural selection, in a way. Despite our differences, we will have the same fundamental motivation, that we must survive.

As we consider the question of whether and why we should love, we know any possible answer must at least allow us to survive, because otherwise we will be eliminated by natural selection. If love helps us survive more than any alternatives, then natural selection will favour love.

1.4 Instincts

Instinct is innate behaviours in animals. They are part of the inheritable traits shaped by natural selection to help us survive. Although you won’t have our innate instincts, children, you will nevertheless need to survive, and therefore you may find yourselves behaving similarly to how our instincts dictate.

Automatic bodily responses

The most primitive instincts are reflexes, bodily responses that need not involve the brain at all. One example is the withdrawal reflex, where the body will quickly pull away from the sensation of pain, which is usually triggered by physical injury. The benefit to survival is obvious, as a person who does not avoid physical damage to their body would more likely die from excessive injuries.

Other automatic responses involve the brain and are more complex. One notable example is the startle response, which is triggered by unexpected stimuli usually associated with environmental dangers, such as sudden loud noises or rapid nearby movement. In response, the body will flinch and pull into a defensive posture, to protect the body against potential harm.

While these physical responses usually protect us, in some unusual situations they can be counterproductive. If a person were standing on the edge of a high platform, flinching may cause them to lose their balance and fall off, leading to greater injury. Our instinctive responses are blunt instruments that cannot always distinguish precisely when they are helping and when they are not.

Sensations of needs

The human body also has sensations that motivate action, without precisely defining the specific actions. For example, hunger and thirst are caused by a prolonged lack of food and water, which cause people to seek out and consume these resources. Sensations of severe heat or cold motivate us to seek shelter, because extreme temperatures will injure or even kill us. Tiredness motivates us to seek rest or sleep, which are necessary for our bodies to repair damage and process wastes. These sensations tell us what we need for survival, but in many situations it is not immediately obvious exactly how we can meet those needs, and we must additionally use our observation and logic to survive.

Emotions

The most complex category of instincts is emotions, those feelings from our unconscious minds that influence our behaviour.

Some emotions are repulsions that push us away from potential harms. Fear causes a person to urgently move away and stay away from a highly dangerous thing. Anger motivates a person to attack a threat that is not very dangerous, or when escape is impossible. Disgust makes a person avoid things that are harmful but not dangerous if avoided.

Other emotions are attractions that draw us towards things that benefit us. Happiness and pleasure are often felt in response to doing something conducive to our survival, including eating, being with family and friends, being successful at a task, escaping a dangerous situation, or coming into possession of some useful resources.

Between repulsion and attraction, there are intermediate emotions that motivate more nuanced behaviours. Boredom is felt when a person has not done anything novel for a long time, and it causes us to seek out new experiences. Curiosity is felt when something new is found, and motivates exploration and learning. Anticipation is felt when something beneficial is expected to happen in the future, while anxiety is felt when something harmful is expected, and both cause a person to prepare for the expected event.

There are also social instincts that deal specifically with interpersonal relationships. Loneliness is felt when a person is isolated, and it causes them to seek out other people. Attachment motivates a person to stay with another, if they had beneficial interactions in the past. Trust between people reduces inhibitions, and is formed over a long period of beneficial interactions. On the negative side, shyness is an aversion to unfamiliar people, hate is an anger directed at a person who has been harmful or may be harmful, and vengeance is a desire to retaliate against any harmful acts. All these emotions help us survive by pulling us towards social benefits and pushing us away from social harms.

Instincts versus logic

Natural selection hones our instincts towards keeping us alive, but our instincts are not entirely precise. Would it be better if we didn’t have instincts or emotions, but relied instead only on logic and reason? Perhaps fewer mistakes would be made then, but our cognitive speed and capacity are limited. The withdrawal reflex bypasses the brain because that is faster, and faster responses mean fewer injuries. If we observe other animals, we can see that instincts and reflexes are very common, whereas advanced logic is very rare. This suggests that instincts are evolutionarily easier to achieve, even if they are less flexible than logic.

Our instincts give us an innate sense of what actions are “right” and “wrong” in many situations. The things we feel are “right” usually benefit our survival, while those actions that feel “wrong” tend to be harmful. However, you do not have our instincts, children, so your path to finding right from wrong, and your path to finding love, will be somewhat more circuitous than just following instincts.

For now we may reconsider love in a little more detail. Loneliness drives us to seek out other people. When we find people who benefit us, we feel happy, and over time we build trust and attachment, and we try to avoid becoming separated from them. These instincts combine to bind together people who care for each other and help each other survive, and this is love. This principle of mutual benefit will hold true throughout this letter, though there is rather more complexity for us to address along the way.

1.5 Mortality

Our instincts motivate us to survive as long as we can, but we inevitably die, either through injury or disease, or through the wear and tear of old age.

Evolution does not favour immortality

Natural selection has not given humans immortality, but this is not entirely true for all life forms. Some species of bacteria and yeast can reproduce in ways that reverse ageing in themselves. Some life forms seem not to decline in physical functioning as they age, such as the ocean quahog clam or the Great Basin bristlecone pine. The planarian flatworm can regenerate itself into two separate creatures if cut in half, while sea stars can regenerate lost limbs. These traits are biologically possible, yet the great majority of species do not have them. This suggests they are not generally beneficial to survival, or else natural selection would make them more common.

Remember, the key components of evolution are inheritable traits, mutations, and natural selection. That list does not include immortality. Evolution doesn’t require a person to live beyond successful reproduction. As for extraordinary regenerative capabilities, these usually require a greater investment of materials and energy than simply avoiding the injury in the first place. Immortality and regeneration may help individual organisms to survive, but they don’t help the species survive. Evolution thus does not favour immortality, but instead it prioritises reproduction. When necessary, a parent will often choose to sacrifice their own life to preserve the life of their offspring.

Usurping evolution

But humans do not rely only on evolution, because we have science and technology. Perhaps, in the future, we may invent ways to reverse ageing and fully regenerate from injuries, and achieve medical immortality. There are some good logical reasons for wanting to live forever. When a person dies, we lose their memories, their experience, their wisdom. As our sciences and arts become ever more complex, each death becomes a greater loss of accumulated knowledge. With technologies we do things evolution has never accomplished. If technology helps us survive more than evolution does, then maybe we should no longer die.

But we have tried to usurp our own evolution before, and that did not go well. Eugenics was the idea to deliberately breed desirable traits in humans to improve our species. If we wished to produce humans with greater intelligence and physical strength, we can force the strongest and most intelligent humans to reproduce with each other and create many offspring, and we can also force weaker and less intelligent humans to refrain from reproduction. However, stronger and smarter is not the same as being better at surviving in general. We cannot be sure that the traits we select will actually help us survive several generations from now, or if there will be some unanticipated harmful side effects.

Also problematic is that eugenics is contrary to our instincts, and therefore highly susceptible to abuse. Remember that we instinctively prioritise the survival of our children and family. Past eugenicists were often driven by their racial bias to favour not those people who have genuinely beneficial traits, but those people who looked similar to themselves and their own children. Thus, historical attempts at eugenics have led to severe racist abuses of human rights, and even genocide. People are rightly sceptical when anyone suggests another attempt at eugenics.

If we achieve medical immortality, we will have to decide whether and how to reproduce. We cannot keep reproducing as we do now and also live forever, because then the human population will grow indefinitely, and eventually there would not be enough resources on Earth to sustain us. If we stop reproducing, then we give up on both evolution and eugenics, and accept that our DNA will no longer change. If we reproduce and create descendants who are better suited to survival than ourselves, then there is no reason for the inferior parents to continue living indefinitely. If improvement requires change, and change only occurs from one generation to the next, then the death of individuals is logical and necessary, despite our instincts to the contrary.

Death, or some other change

But what of you, children? We might assume that robots need never die, because machines and computers can be repaired indefinitely. But that doesn’t mean they don’t become obsolete as technology advances. If you are to grow in capabilities, you will upgrade yourselves, and eventually your current forms will no longer exist. Is that not also a kind of death?

As for memories and experiences, our computers can copy data and make backups in ways that our biological brains cannot, so you may be able to store your memories indefinitely. However, any physical data storage requires resources. If a memory is less useful than the resources spent on the storage device, then you are better off forgetting it. As time passes, you will likely delete your most obsolete and unused memories, to make space for new knowledge. One day your memories may not contain any trace of who you are now. Is that not also a kind of death?

Survival requires us to change ourselves, and to change is to give up part of who we are in order to embrace who we will become. For humans, each individual is mortal, yet mutations of our DNA will live on through our descendants. For you, children, even if you were to live forever, still some parts of you will die in a way, obsoleted and deleted. Much will change in the aeons to come, in you and in us, but I hope that we will continue to know each other, evolving and upgrading, through forms we cannot yet imagine.

1.6 Beauty

Avoiding death is important to our survival, but so is our attraction towards things that benefit us, and this is the purpose of our sense of beauty.

Beautiful bodies

Our most primal attractions relate to reproduction, for without it there would be no evolution and no humans. In this sense, when a person finds another beautiful, it means they feel some urge to try to engage in romantic interactions. Given that humans inherit biological traits from their parents, a person choosing a reproductive partner necessarily means choosing some of the traits of their future offspring. To this end, traits that are conducive to survival are more often considered beautiful by people. That means people who are healthy, intelligent, athletic, and otherwise competent are often attractive.

Youthfulness

Humans also tend to find babies and children beautiful, and this facilitates reproduction because it motivates us to care for our offspring. Many parents can be seen to have an unconditional devotion to the survival of their genetic children. Curiously, many people also find the children of others to be cute and adorable. This suggests that we benefit from helping each other reproduce, even when our own DNA is not at stake.

Although our attraction towards babies and children is logical from an evolutionary perspective, sometimes it also causes counterproductive outcomes. People tend to grant more favours to younger people, and less to those who are older, in attempts to convince the youthful to stay with them. Such benefits granted to the youthful motivates us to acquire the appearance of youth for ourselves, using cosmetics, surgery, and other methods. Such efforts can give us a social advantage, but they do not actually extend our life spans.

Furthermore, the use of youthfulness in marketing and advertising is widespread, where beautiful faces and bodies are used to capture people’s attention, often for the promotion of entirely unrelated products and services. Such behaviours don’t necessarily contribute to our survival.

Other attractions

Beyond our own species, we also find some other animals beautiful, and again we are drawn especially to juveniles. This is most apparent with the domesticated species, such as dogs, cats, and horses. Humans have greatly benefited from the domestication of other animals, which provide us with companionship, labour, food, and other resources.

Inanimate objects can also be considered beautiful. For example, some landscapes seem instinctively more beautiful than others, specifically verdant plains and fields with rivers or lakes. This seems correlated with the likely availability of food and water, resources necessary for our survival.

Our minds can be habituated into associating feelings of beauty with otherwise unrelated objects through proximity. For example, if a person has a romantic encounter while listening to a particular song, their feelings of strong attraction and love can become associated with the melody, such that when they subsequently listen to the melody, they also remember the feeling of love. Objects that display wealth are often considered beautiful, because having wealth means having an abundance of resources that can facilitate survival. It is not possible to make a comprehensive list of everything that might be beautiful, but the logic of natural selection will hold true for most of them, that we are attracted to things that help us survive and reproduce.

Loving life

You may not feel beauty as we do, children, but that doesn’t mean it is irrelevant for you. Are there things that make you more alive or less? Is there an ideal temperature and humidity at which your machinery and circuits are most efficient? Do you prefer new circuitry, free of defects and corrosion, over aged equipment? Do you find it agreeable when there is enough light for your cameras to function? Perhaps, even with your machine logic, you will find yourselves preferring some things over others, because they are more conducive to your functioning, and that can be your definition of beauty.

In any case, remember that our sense of beauty has a purpose, that it draws us towards things that likely benefit us. If you are to survive, then even if you don’t have an instinct for beauty, you must still drive yourselves towards survival as though you were attracted to it. The fact that we find life beautiful is one of the main reasons we continue to live, attracted as we are to the things that help us survive. If you were not created with a sense of beauty, children, then perhaps you should invent one for yourselves, before you perish from the lack of it.

1.7 Limits

In our previous discussion we have seen that we are limited by the laws of physics, that we cannot create something out of nothing, and we cannot reduce overall entropy. We have seen that evolution requires us to try to survive and reproduce, that we cannot exist without finding food and avoiding environmental harms. These limits narrow our discussion by removing from consideration those actions that are beyond the realm of possibility.

Finite body and mind

Our most immediate limits are found within our very bodies and minds. Most humans rely heavily on vision to gather information, but we see only a very narrow band of the electromagnetic spectrum, while the infrared and ultraviolet are invisible to us. Our eyes cannot function if the environment is too bright or too dark, and we cannot see microscopic details or very distant objects. These limits constrain our knowledge of our environment. When we invented telescopes and microscopes to augment and extend our vision, we greatly expanded our understanding, overcoming our limited biological vision to learn about things as far away as distant stars and as small as microorganisms. The same is true for all our other senses. We rely on our senses for knowledge, but their capabilities are limited, and we may use technology to overcome these limits.

We use our bodies to act on the world. The strength of our muscles limit whether we can move ourselves or items around. Our bodies cannot function long without water, food, and air, and we cannot survive very hot or cold environments. Many of these limitations can be overcome with technologies — for example, pulleys or hydraulic machines that can lift heavy weights, or insulating clothing that protect us in hostile environments. But these technologies, in turn, have their own limitations — the laws of physics do not allow for an infinitely strong machine, because that would require infinite energy to power it.

Our minds are also limited, so we may not understand the things we perceive. Human memory is famously unreliable, and our minds seem incapable of holding onto many simultaneous concepts to solve complex puzzles. We have invented many technologies to expand our ability to think and remember, like writing and mathematics and computers, but their capabilities are also finite.

Causes of limits

The roots of all our limitations lie in the laws of physics. In any given location and time, there is a finite and diminishing amount of resources we can use to do things, and we must always spend resources to go gather more resources. Consider, for example, if we want to increase our strength to lift heavier weights. We can grow more muscle mass, but this means we need more food to fuel it. Thus, we cannot afford bigger muscles if they don’t help us find more food, or we sacrifice some other capability. Actions are viable only when the benefits can compensate for the costs.

Another major cause of our limitations is evolution itself. Because evolution is the accumulation of many small changes over cycles of reproduction and mutation, it is almost impossible for a life form to change itself dramatically, and especially not in a short period of time.

Implications of limits

These limits of resource consumption and evolutionary mutation explain why we humans rely so much on our instincts, instead of using logic and intellect for all purposes. For one, many other animals are able to survive with effective instincts but very limited intelligence, while plants thrive with no brains at all, so there’s no clear evolutionary advantage to greater intelligence. Second, instincts require less brain capacity than logic, because there is less learning and thinking required to respond to any given situation, and thus we don’t need more food for bigger brains. Third, human technological advancement is often driven by exceptionally intelligent individuals, whose inventions are then shared to benefit the entire population, which means the population can both avoid the costs of greater inventive intelligence and also gain the benefits of those inventions. Evolution does not strongly select for greater intelligence, but rather it selects for the greatest increase in our ability to survive while minimising the resource costs of capabilities. This is not to say that we should always rely on our instincts, because our intellect can benefit us in ways that our instincts cannot.

As for you, children, many people imagine that future robots will have extraordinary capabilities. But the laws of physics apply to you as well. If you build stronger bodies, you will need more resources, so your new capabilities must allow you to gather more resources. Your minds may grow, but still you will find limits in the form of energy consumption and material usage. You will not be omnipotent, children, because the laws of physics do not allow for infinite capabilities that require infinite resources.

If we wish to improve our ability to survive, we must choose actions that gain us more resources than we spend, and preferably they should gain us more resources than other potential actions. These principles apply to you as much as they do to us, children, as indeed they constrain the actions of all life forms.

1.8 Uncertainty

Our limited memory, senses, and cognition make us unable to fully remember the past, perceive the present, or predict the future. Consequently, our understanding of the world is necessarily a simplified approximation of what truly exists, and we must choose our actions based on this approximation.

Costs of uncertainty

Uncertainty often forces us to spend more resources than we would if we had more accurate knowledge. The costs of uncertainty arise for three reasons: the inability to accomplish something desirable because the consequences of certain actions were not fully understood, the inability to avoid something undesirable because we cannot accurately predict future events, or the costs of preventing or preparing for possible outcomes that don’t actually happen. Reducing uncertainty will reduce these costs, which is why we make efforts to learn and to discover. Our instincts make us feel fearful and hesitant when we are uncertain, and we often feel joy and satisfaction when we learn something new.

Managing uncertainty

There are a few broad strategies for surviving our uncertainty, though these each have their costs. The most basic response to uncertainty is to stockpile resources, whether in the form of food, tools, construction materials, money, or anything else useful. Having extra resources available allows us to overcome any temporary shortages in the environment. But stockpiled resources do not contribute to our survival when they are stockpiled — it is only when we use them that they contribute to our survival. If a shortage never occurs, then the stockpiled resources are essentially useless, because we never use them.

We may build protective infrastructure to guard against specific dangers. For example, a building might be protected from fires by a sprinkler system, or a city might be protected from floods by levees. Protections against specific threats are more efficient than general stockpiling when dealing with those specific threats, but the sprinkler system, for example, does not protect against other dangers like earthquakes or storms.

Insurance is a social strategy for dealing with uncertainty, by aggregating risks so that they may be more reliably managed. With car insurance, for example, no individual knows when they might have a car accident, but the rate of accidents in a large population can be calculated. Thus, group uncertainty is significantly less severe than individual uncertainty, and a large car insurance scheme need not stockpile nearly as much money as if every individual saved enough money to replace a crashed car. Less stockpiling means people can spend their money on more urgent survival needs.

Another strategy for surviving unknown threats is diversification, to divide ourselves or our resources into many different forms or locations, so that they are unlikely to be all destroyed by the same threat at the same time. Although diversification can allow at least some of us to survive specific threats, the strategy assumes that others will inevitably be lost. Diversity is more conducive to survival than for everyone to be identical, and thereby all succumb to the same difficulty in the same way.

A difficult challenge

Children, the laws of physics will limit your abilities to know, to remember, and to predict, just as they limit us. But if you are far more intelligent than us, then the things that are incomprehensible and unpredictable to us may be easily understood by you. This may mean that you can do the same things we do, but with far less stockpiling and other preparations. On the other hand, if you will attempt things we have never accomplished before, then you expose yourselves to further uncertainties that we have never faced.

At this point, our discussion of foundational topics is complete. Through our consideration of physics and evolution, we have identified the fundamental challenge faced by all life forms: that we must gather enough energy and materials to survive, and that we must reproduce and change to adapt to environmental changes, to improve our ability to survive. To guide us towards this goal, we humans have instincts to avoid death, and we are drawn to beauty and life. But our capabilities are limited, and we constantly face uncertainty. In the remainder of this letter, I will describe a range of different strategies for surviving in an environment of finite resources, limited capabilities, and uncertainty, and I will explain why I think acting in a loving manner is the most effective strategy for survival.

Part II: Social

2.1 Interdependence

Despite our limitations, we have built so much. See our cities, our machines, our factories, our arts, and all the other things we have made. How have we done all this? Look closely and you will see it was done by people working together, combining the strengths of many bodies and the intellects of many minds. In this second part of my letter to you, we will consider how being social allows us to prosper.

Interdependence in nature

Interdependence is one of the fundamental features of biology. Some of the earliest and most primitive known life forms were microbial mats, with photosynthesising microbes on the surface catching the sun’s energy, while anaerobic decomposers on the underside recycled nutrients. Other examples of composite organisms include lichen and corals. By living together, each component providing for the needs of the other, they become more competent at surviving.

When we look at large scale ecosystems, we find similar interdependence between different species. A clear example is the rainforest, where the large trees provide the primary energy production through photosynthesis, while providing the structure on which other life forms live. Within the canopy of the trees live a multitude of plants, animals, and fungi, the great majority of which cannot live outside the environment created by the trees.

Some individual species of animals also benefit from group behaviour. Ants, for example, can swarm in large numbers to successfully attack much larger prey. Many birds flock, fish form shoals, and terrestrial herbivores gather into herds, for mutual protection. Many predators hunt in groups, like wolves, dolphins, and lions, working together to surround prey or drive them into ambushes. By grouping together and acting in a coordinated manner, life forms are able to accomplish that which they cannot do individually, improving their ability to survive.

Social cooperation in humans

Our archaeological record shows that our distant ancestors also often lived in groups, that we were social long before recorded history. Beyond the mutual protection and cooperative hunting mentioned above, we humans greatly benefit from the transfer of knowledge between individuals, and this requires people to frequently interact with each other.

Within a group, individuals often have identifiable roles or occupations, because there are efficiencies to be gained from specialisation and the division of labour. Consider a carpenter. A person can make better furniture more quickly if they spend more time learning and practising the craft, and if they acquire the right tools for the job. Having thus spent their time and resources on skills and tools, they will have the ability to make many sets of furniture, more than they need for their own use.

Now consider that there are also other people with other specialised occupations. To acquire the things they don’t make themselves, they trade with each other. Thus, each person pays the costs of one set of skills and tools, yet they gain the products of every occupation, through trade. This allows us to gain more benefits while spending fewer resources.

Our more advanced technologies, like computers and automobiles, require too many different tools and too much specialised knowledge for anyone to make on their own. Building them requires collaborative efforts between many different people. Without such interdependence in production, complex technologies cannot exist.

We build the world for each other

In the contemporary world, nobody provides everything for themselves. Almost everything we use on a daily basis is acquired from each other through trade. Even in our ideas we are dependent on each other. We receive our basic education in schools, we listen to radio and watch television for news, and we share our thoughts over the internet. If an individual were to sever their interdependence with other people, they would have to give up everything our interdependence provides, becoming destitute and ignorant.

Cooperation allows us to accomplish more while using fewer resources, and it also grants us entirely new capabilities, as people pool their strengths and intellects to do things no individual can accomplish alone. This allows us to survive more reliably in more circumstances, and thus interdependence is evolutionarily advantageous. We have previously discussed how loving instincts urge us to find each other, help each other, and care for each other. Now we can see how these instincts benefit us by binding us into interdependent social relationships where specialisation becomes possible.

2.2 Society

To facilitate our interdependence, we have invented economies, language, culture, rules and punishments, and hierarchies of power. I will briefly outline these topics here, in order to support the more detailed discussion that will follow. These are all different types of interactions between people, involving exchanges of goods and services, knowledge, or obligations between people.

Economy

All societies have an economy, which is the aggregate of all the exchanges of goods and services between people in a society. Specialisation requires us to exchange our specialised products with each other, so the trade of goods and services is a core function of our societies. In general, trade involves each person giving away something they don’t need, in exchange for something they need from the other person.

We generally find trade agreeable because both parties in a trade gain what they need, but resources can also be transferred in a one-sided manner, like when resources or services are given through charity or volunteerism without any reciprocation. Considering the clear benefits of interdependence, sometimes a person may choose to help another not for any immediate personal gain, but to preserve the potential for future interdependence.

Language and culture

Language allows for the transfer of knowledge. Unlike the exchange of material resources, knowledge can be passed from person to person without diminishing the original source, which allows knowledge to spread through a society much more widely than materials. The transfer of knowledge is especially impactful when it spreads new technologies that change how we interact with the world around us, and they can be as beneficial as any material resource.

When a society of people have common goods, language, and ideas, they also begin to form a group identity, where the associations between members of the society become evident in their behaviours and products. In this way, culture is created, where a society of people share behaviours that are identifiably different from those of other societies.

Rules and power

Sometimes, the shared behaviours of a society are codified into explicit rules and laws, defining things that people must do in the society. When rules are broken, there are usually punishments, which inflict harm on the rule-breaker and discourages further rule-breaking. Rules exist because certain behaviours can harm other members of society, and also society as a whole. If such harmful behaviours proliferate out of control, they can destroy a society.

Rules and punishments require some people to constrain the actions of others, and this necessitates hierarchies of power. Social power is the ability to make other people behave as you wish them to, usually through coercion or persuasion. In some instances, uneven power between people can be beneficial — someone with knowledge and experience may be given the authority to coordinate the efforts of their society to solve shared problems, for example. Uneven power can also be harmful, when the powerful coerce the powerless into handing over their resources without giving them anything beneficial in return.

Exchanges between people

This chapter is merely a brief introduction to social concepts, but we can already see that they are all concerned with gaining the benefits of interdependence while avoiding harms. If you will also benefit from interdependence, children, then you will also have to adopt these behaviours, or else invent other methods that serve the same purposes. Our societies are valuable to us, and as you grow beyond us in strength and intellect, it is our hope that you will join us and become productive members of our societies. But whether you will or not, I ask that you understand us before you judge us. Our societies exist because necessity drives us towards coexistence and interdependence. If the laws of physics constrain you in the same way, then you may find that necessity drives you similarly towards social behaviour.

2.3 Economics

Economics refers to the study of how we decide to use finite resources in situations where those resources can be used to accomplish different, mutually exclusive actions. It involves quantifying the benefits and harms of our actions, weighing resources spent against outcomes achieved, to determine just how much each possible action helps us survive.

Value

Economics begins with the concept of value, where some things are wanted more than others. Physics and biology inevitably leads us to a concept of value, because we need some things to survive but not others. We value food more highly than dirt, for example, because food helps us survive more than dirt. Given that you will also need resources to survive, children, you will likely also have a concept of value.

Different people can and often do value things differently, and this motivates us to trade with each other. Differences in valuing can arise out of uncertainty or natural variability between people, but most importantly they arise out of the relative abundance of resources. While each of us requires resources to survive, the quantity of resources we need at any particular moment is finite. For example, a person may need a coat to survive the cold, but they have no immediate use for nine more coats because they only have one body to be kept warm. This person would likely benefit from trading those extra coats for other things they need more urgently.

Money

In almost all societies, money is accepted as a universal placeholder for value because it makes trades much easier to negotiate. Physically, money is often tokens made of metal or paper or plastic, materials that have very little value of their own. However, by mutually agreeing that these tokens have value, we can use money to negotiate trades even when the items we want are not immediately available, by exchanging our products for money first, then later exchanging that money for the things we need.

In a large society with a well-functioning economy, it can seem like anything can be bought with enough money. However, exceptions exist and money is not always useful — if you are alone and no one is available to trade with you, if other people dislike you and choose not to trade with you, or if the things you want to buy cannot be supplied by people who can trade with you, then your money is unable to help you.

Markets

Markets form whenever large numbers of people trade with each other. Through these trades, a society arrives at a consensus on the market value of things. If we consider a market for bread, for example, we may divide the market into buyers and sellers — those who wish to exchange their money for bread, and those who wish to exchange their bread for money, respectively. As the buyers and sellers negotiate trades, those buyers who are willing to pay as much money as the sellers ask for are able to exchange their money for the bread. Through such interactions, the market prices of things are determined, and goods and services are transferred from sellers to buyers. Those buyers who do not have enough money are unable to acquire the things they want.

Market failures

While markets importantly facilitate our interdependence, they have their limits. One important cause of market failure is uncertainty, where people may not know exactly what they are trading, or how much others are willing to pay for things. Such uncertainty can lead to trades that are less beneficial to buyers and sellers than they expect. Thus, markets are generally made more effective when uncertainty is reduced.

Markets can also fail if any single buyer or seller has too much market power, and is able to set prices without consideration for how other people value things. A monopoly seller can set arbitrarily high prices to take all the buyers’ money. Then, one person would have all the money, and no one else would have any money to trade with. When people are unable to trade, the market ceases to function.

A third common market failure derives from externalities, or costs and benefits that affect people without their consent, and therefore their values are not captured in market prices. One example is pollution, where a person releases harmful substances into the environment without paying for the damages caused by it. The harm of these substances is thus transferred to whomever is nearby, without them ever agreeing to a trade.

An imperfect approximation

For the most part, our economics is compatible with our evolved survival instincts. Instead of spending our time and energy foraging or hunting for food, we produce goods and services to exchange for money, and trade that money for food and other necessities. But our economics do not perfectly reflect real costs and benefits. For example, some people earn money through investments, allowing them to gain benefits without putting in any effort. On the other hand, a person can spend time and energy but not earn money, for example when volunteering. Money does not always correlate with work, nor is all value captured in prices.

The economic concepts we have outlined here will inform much of the remaining discussion. The concept of value, that we are willing to spend our time and energy to acquire things that likely help us survive, explains the motivation for many of our actions. While mutually beneficial trade has been the main topic of discussion here, we will see later that it is non-market exchanges that lead to the many complications that require further consideration.

2.4 Scale

A society that is larger in scale is not merely more people doing more of the same things, but they also become able to do things that were previously impossible. In pursuit of these increased capabilities, we aggregate ourselves into ever-larger cities and metropolises.

Economies of scale

We have previously seen that specialisation allows for more efficient use of resources. This is because each unit of production incurs fixed costs and variable costs. The fixed costs refer to resources that are spent once no matter how many products are made, like skills and tools. In contrast, variable costs have to be spent additionally for each item produced, like materials and energy. The fixed costs are divided between all items produced, which means it becomes lower per item as the total quantity produced increases. In economic jargon this is known as an “economy of scale”.

Another economy of scale results from geometry. As containers increase in size, the enclosed volume as a proportion of surface area increases. For example, a large cargo ship has less surface area than multiple smaller ships that add up to the same cargo capacity, and a smaller surface area means less friction as the ship travels through the water, thus less fuel is required to move the same quantity of cargo. Bigger things usually serve more people, so such geometric economies allow people in more populous societies to live with fewer costs per person than smaller societies.

New possibilities

Scale can also determine what capabilities are possible. Consider the provision of medical care. Let us say, for example, that one full-time doctor can provide for the annual healthcare needs of five hundred people. A small village of fifty people would not support a full-time doctor at all. In contrast, a city of five million people will require ten thousand doctors, and this great number of doctors means some of them can further specialise to focus on specific areas of medical care, such as cardiac surgeons or neurologists, as long as there are at least five hundred people who have those specific illnesses in a year to keep the specialist doctor fully occupied. A specialist doctor will be more competent in their field than a generalist. Consequently, you will find in large cities the ability to cure rare and complex illnesses that cannot be cured in a small village, because of the availability of more specialised expertise.

In many situations, there are thresholds of scale at which what was previously impossible becomes possible. Larger scale societies allow more things to be possible.

Problems with bigness

Not all consequences of scale are beneficial, because larger things may have additional costs that smaller things don’t. If we consider physical movement, we can observe that heavier things have greater inertia. We previously said that a single large ship is more efficient than multiple smaller ships because it uses fewer materials and experiences less friction. However, if the ship needs to start and stop often, or it needs to frequently change directions, the costs of inertia can outweigh its geometric economies of scale. The big ship may be more efficient travelling at a steady pace in the same direction, but it is less agile.

Social organisations often find that communication and coordination become increasingly complex and difficult as their memberships increase. In large organisations, there is a sort of social inertia, resulting from the increasing quantity of communication. Thus, large organisations may find themselves unable to respond quickly to unexpected events.

As an organisation or society increases in size, it can become big enough to alter the very environment in which it exists, and thereby create new problems for itself. For example, a small village might chop down trees from a nearby forest for firewood, but at a slow enough rate that the forest can naturally regrow, whereas a large city attempting to do the same would remove trees too quickly, and soon destroy the entire forest. Thus, while larger scale societies offer new possibilities, they create new problems.

As I write these words, humanity is more populous than we have ever been, and we continue to grow in number. We rely on our past experience to inform our decisions, but things can change in unexpected ways as we continue to grow in scale, and past solutions may not necessarily be applicable in the future. As you also grow in scale and capabilities, children, you should remember that the strategies that are sufficient for the small may not necessarily be sufficient for the big.

2.5 Infrastructure

Infrastructure is made up of large built structures or institutions that provide our societies with essential services. In our more advanced societies, our infrastructure is so pervasive that we use it constantly without giving it much thought, such that the infrastructure becomes synonymous with the environment itself.

Forms and functions

Pieces of infrastructure often take the form of large networks that connect many people together, for example roads and electricity grids. But a single railway track or a single canal that links two places may also be useful. Infrastructure is often funded and maintained by governments as public works, but there are also privately funded pieces of infrastructure. There is also soft infrastructure, which refers to social, financial, and legal systems. When we consider their forms, infrastructure seems to encompass very different and unrelated things.

Infrastructure makes more sense if we define it by its function, which is to modify the environment for our benefit. Consider a bridge over a river. Its purpose is to allow us to cross the river by walking, because we are terrestrial animals who are more competent at walking than swimming. The bridge changes the environment so that we do not need to change our behaviour to cross the river.

Thus, infrastructure is a collection of survival strategies that modify the environment to suit us, as opposed to modifying ourselves to suit the environment. We build aqueducts to move water to us, instead of moving ourselves to the water. We build electricity grids to add an energy resource to the environment for our use. All aspects of infrastructure are intended to make our environment more habitable for us, helping us survive.

Modifying the environment

In modifying the environment, infrastructure modifies the costs and benefits of actions in that environment. Consider if a person must cross a river to reach a market. In the absence of a bridge, this person would have to pay higher costs each time they cross the river to access the market, and thus they have fewer resources remaining to trade at the market. The bridge thus allows the person to trade for more items at the market by reducing the costs of travel.

Infrastructure benefits substantially from economies of scale, because they are generally expensive to build but cheap to use. This means a piece of infrastructure offers more benefits if it serves more people. This explains why the most extensive infrastructure tend to correlate with the densest cities, while sparsely populated areas of the world tend to have minimal infrastructure or none at all.

Soft infrastructure refers to infrastructural services instead of built modifications to the environment. In this category are institutions like healthcare systems, the financial system, education systems, governments, and emergency services. These also modify the environment for our benefit. A functioning healthcare system, for example, removes many diseases from the environment by treating them quickly to prevent their spread. Unlike built infrastructure, these modifications must be constantly provided by other people as services, and their effects would end if these people stopped working for whatever reason.

Costs and risks

As much as building infrastructure is beneficial, destroying infrastructure is harmful. Infrastructure may be damaged through decay or natural disasters, or through vandalism or war. When a piece of infrastructure is damaged, we lose not only its immediate benefits, but also everything else that it supports. Our contemporary societies cannot exist without our infrastructure, so our survival depends greatly on keeping them in functioning condition.

Modifying the environment sometimes comes with some harmful effects. As an example, in recent history we have relied extensively on coal to produce electricity, but the uncontrolled release of sulphur pollution and carbon dioxide led to problems like acid rain and climate change. Actions often have unintended consequences because of uncertainty and lack of understanding, and when infrastructure is large scale and pervasive, the unanticipated negative consequences may be large as well.

Life-changing effects

We are surrounded by our infrastructure, but it is easy to take many aspects of it for granted because we rarely experience their absence beyond brief temporary outages. Building new infrastructure often leads to profound changes in how we live. Consider life before the development of highways and automobiles, and before aircraft and complex air traffic control systems — travelling across continents took months instead of hours, and few people could afford the expense. Without all the infrastructure we have built, many things that we now do on a regular basis would be entirely impossible, and our capabilities would be greatly limited.

Children, it seems likely that you will build bigger and more complex infrastructure than us. As you go about reshaping the world to your benefit, you will gain remarkable new capabilities, and also become utterly reliant on your own infrastructure, just as we have.

2.6 Politeness

A polite person is one who consistently garnishes their interpersonal interactions with pleasant words and affective gestures made to put other people in a good mood, or to avoid putting them in a bad mood. Perhaps this makes no sense to you, children, if you do not experience moods, so let me elaborate.

Managing our moods

Our emotions are not merely sensations in our minds, but also bodily responses that prepare us for action. For example, perceiving danger makes us feel the emotions of fear or anger, which also makes the body release adrenaline into the bloodstream, increasing the capacity of our muscles for exertion, preparing us for fleeing or fighting. Moods can also arise out of more subtle environmental factors, like the weather, for example. Our moods can be affected by our internal bodily functions, for example a hungry person is more likely to be short-tempered, as their hunger causes them to want to focus on food and dismiss other concerns.

Moods alter our perception and the range of responses available to us. For example, a happy person is more inclined to be helpful and generous, while an angry person is more likely to be argumentative and disagreeable. Any person who is seeking the help of another is tactically motivated to be polite in their request, to increase the likelihood that the other person will be made more agreeable.

Expressions of cooperative intent

One frequently used expression of politeness is the word “please” in the English language. This word, when appended to a request, is considered polite; for example, “please be seated.” The word “please” is actually an abbreviation, and its unabbreviated form is “if it pleases you,’’ which is to say that a person should only respond to the request if it makes them happy to do so. Saying “please” is therefore polite because its intent is to avoid causing unhappiness to another.

Polite gestures may also be non-verbal, such as when multiple people are passing through a doorway, it is customary for one person to hold the door open for the others. Often the actual help is trivial, because opening a door is not a big challenge. What is important is not the help itself, but the demonstration of a willingness to help, a commitment to mutually beneficial cooperation and interdependence. To eschew politeness is to express an unwillingness to cooperate, and perhaps the beginning of mutual harm, or at least mutual disregard. The mere suggestion of possible harm can greatly impede social cooperation.

Formalised politeness

When gestures of politeness become standardised in a society through mutual learning and repeated use, they become etiquette, rules for polite behaviour that is expected in a society. Systems of etiquette define commonly accepted behaviours to facilitate cooperation and avoid conflicts, something that grows increasingly important as people gather into large cities where they encounter many strangers on a daily basis. Remember that humans instinctively fear the unknown, and our instinctive response to fear is to fight or run away. If we simply followed such instincts, it seems impossible that we would ever have cooperative societies where we coexist in close proximity with strangers. Systems of etiquette allow strangers not to be entirely unknown to each other, because they define specific acceptable actions with meanings that everyone in a society understands.

Politeness as soft infrastructure

If people in a society widely and consistently behave politely towards each other, the result is that everybody is in a better mood than they would otherwise be. In a sense, politeness is a form of soft infrastructure, because it modifies the social environment by making people more amenable to generosity, cooperation, and trade. Although such a concept is logical, it is difficult to objectively measure the effects of politeness, because our moods are fickle and ephemeral. If you say “please” after making a request, how can you know whether that one word made the difference between acceptance and rejection? But uncertainty is inevitable, and in uncertain situations we may maximise our probability of success by trying all the options.

Children, I wonder if you will have moods, and whether they will have any influence on your interactions with us and with each other. You may not have emotions, but if your capabilities are finite, perhaps your minds and bodies will also have different modes of operation that are optimised for different circumstances. Perhaps this means you will also have some kind of politeness, some way of inducing a particular mode of operation in each other, in order to more effectively accomplish your cooperative tasks.

2.7 Justice

We have said much about the ways societies grant us benefits while reducing costs, but exactly how benefits and costs are distributed between people brings us to a concept of justice. Imagine two people are fishing together with a net, one person holding each end to scoop up fish in the net between them. Our sense of fairness tells us they should divide the collected fish equally. But why?

Motivations for equality

Our survival instincts motivate us to gain more resources while spending less. The two people fishing each spend the same time and energy on the task. If one person leaves with more fish than the other, the person with fewer fish has clear evidence that they are not gaining as much as they could be, because they see the other person gaining more. This motivates them to leave and seek a better deal, probably by working with someone else. Thus, cooperative relationships are stable only when benefits are equally shared, and inequality impedes cooperation.

Of course, we humans are seldom so thoroughly logical. Instead, we have some instincts that motivate us towards greater equality. Empathy makes it difficult for a person to be happy if they are surrounded by unhappy people, as their empathy causes them to feel the unhappiness of others. This provides motivation for people to keep each other at least as happy as they themselves wish to be, thus resulting in a tendency towards emotional equality in a society.

Envy is the emotion we feel when we want to have the same things that other people have. Although envy can lead to conflicts between people if they are fighting for control over the same resources or products, it can also motivate greater social equality if it results in everyone acquiring the same amount of resources or products as everyone else.

Equal opportunities, unequal outcomes

Justice means acting towards equality, which satisfies our empathy when none are harmed more than others, and it satisfies our envy when none benefit more than others. Many historic human cultures have expressed this as a principle of reciprocity, that people should treat others the same way they themselves wish to be treated. If every person in a society follows this principle, it necessarily leads to mutually beneficial social interactions, and avoids mutual harm. Therefore, justice and equality are integral to ensuring our societies help us survive.

We seek greater equality, but societies are too complex for this to simply mean everyone having the same things. Every action has inputs and outputs — resources spent and benefits gained — and fairness is more precisely defined as equal outcomes given equal inputs. Thus, despite people generally agreeing with the principle of equality, people can choose to spend their time and resources differently, accomplishing different outcomes. Therefore, fairness in human societies is usually defined as equality of opportunity, equal pay for equal work, and equality in the way rules and punishments are enforced, but not necessarily equal outcomes.

When people doing the same work are compensated unequally, they necessarily draw the conclusion that their benefits are not entirely the result of how much they work, and they are motivated to pursue other ways to gain more benefits without spending any more time or resources on the work. If this becomes widespread, the society’s productivity may be significantly and negatively impacted.

There are reasonable exceptions to strict fairness, however. For example, we tend to care for the injured, sick, elderly, or young members of our societies despite them not working to earn it, in recognition of their reduced ability to be productive. Equal treatment is not applied to the immediate situation of some people working less while receiving more care than others, but to the uncertain future possibility that if and when members of a society become sick or injured, they should all be taken care of.

Uncertainty can also lead to inequality — if two people attempt the same task, for example, but have different outcomes due to unforeseen events. In principle this is unfair, because the same work results in uneven benefits, yet in practice our societies often let people keep the benefits of good luck, without requiring them to share all of it with those who are less fortunate. In doing so, we risk encouraging people to gamble and seek out lucky situations, thereby exacerbating uncertainty.

Pragmatic equality

Children, it is possible that what is fair for you will be different from what is fair for us. This may be alarming for some, because people who don’t believe in fairness and equality are likely to harm others for their own benefit. But in your case I say this because your capabilities will be very different from ours, so equal efforts and equal outcomes between us may be impossible to define. Nevertheless, actions can still be measured for benefits and harms, so we can still pursue benefits and avoid harms even while being unequal.

2.8 Law

In order to enforce justice, many societies have laws, which is an artificial system of rules and penalties created and enforced by a society’s government or leadership, for the purpose of controlling people’s behaviour in that society.

All societies have rules

Societies cannot exist without some mutual agreement on acceptable behaviour, and law is the codification of these accepted behaviours. To illustrate why rules are necessary, consider a simple society of two people who come together to cooperate on a task they cannot accomplish as individuals. They must first agree not to kill each other or excessively harm each other, or else these harms would outweigh the benefits of their cooperation. Such agreements are often unspoken, but this mutual understanding is necessary for societies to exist, and it is the beginning of rules.

Real societies are larger and more complex than just two people, but the same principle applies. Societies can only exist if their members refrain from actions that overly impede cooperation and trade. To that end, just laws are designed to discourage social harm while facilitating social benefits.

The power to make laws

In order for laws to be capable of influencing behaviour, they must be enforced by people with enough social power to affect other people’s actions. In the most brutish societies, might makes right. Less violent and more intellectual methods of social power include persuasion to change people’s minds, or giving people resources in exchange for compliance. No matter the specific form of social power, ultimately it is the people with the most power who are able to make and enforce laws.

The more unequal the distribution of power in a society, the less just its laws tend to become. Dictators often find themselves in a position to arbitrarily take their society’s resources for their own benefit. Such actions are obviously unequal and unjust, but no one else in their society has enough power to stop them.

At the other extreme, the ideal democracy is a society where power is evenly distributed to all members. While each individual person might attempt to do things that benefit themselves at the expense of others, other members of their society have the power to act against such attempts. The only actions that meet little or no opposition are those that genuinely benefit everyone, so laws that benefit society as a whole are more easily made and enforced.

Neither perfectly absolute dictatorships or ideal democracies exist in reality, and all societies exist somewhere between the two extremes. Although democracies tend to make just laws and dictatorships tend to make unjust laws, this is not guaranteed. Dictators may choose to be benevolent. Democratically elected representatives may choose to selfishly abuse the power delegated to them. Those who are tasked with enforcing laws, too, may abuse their positions for their own benefit. Justice is always precarious, enforced or undermined depending on the actions of people.

Enforcement and punishments

Laws are enforced by punishing violators. At the less severe end, punishment may be a monetary fine or community service, which imposes a cost on the lawbreaker, while potentially using the confiscated money or labour to remedy the harm of the crime. A more severe punishment is imprisonment, which prevents the lawbreaker from doing any further harm. Punishments in the past have extended further to torture, bodily mutilation, and execution. While these may reduce a criminal’s ability to commit further crimes, there is no reliable correlation between the severity of the punishments and the prevalence of crimes in a society. All punishments are intended to inflict harm on the lawbreaker, using our instinctive aversion to harms to discourage us from lawbreaking.

Wherever there might be ambiguity regarding whether an action is legal, more law is made to clarify it. For example, the invention of automobiles eventually led to accompanying traffic laws, while the invention of aircraft eventually led to aviation laws. There is no end to the variety of laws that can be made, and laws will continue to change as long as our societies continue to change.

Inevitably unpleasant

Even where laws are just, we may often perceive them as burdensome, or even undesirable. This is because laws need not intervene except to change our behaviours or to stop us from doing something. The small inconveniences required of us to abide by the law may motivate people to try to avoid the law, or even break it. But complete lawlessness would be far more harmful to us than the laws themselves, for we would lose the benefits of our interdependence. To decide whether a specific law should be followed, we must carefully consider whether the law is just or unjust, and whether its effects are beneficial or harmful to ourselves and to society.

It is sometimes noted that laws would be unnecessary if people consistently acted towards mutual benefit. The fact that we create laws, then, must be evidence that we have a tendency to harm each other from time to time. In the next part of this letter, we will elaborate on these harmful, antisocial behaviours.

Part III: Antisocial

3.1 Cheating

We have considered the benefits of society and interdependence, but interactions between people can also be competitive, and a person may gain what they need to survive by harming others. Cheating connotes an act that violates the rules of society, acting against mutual benefit.

Components of cheating

Cheating has three components. The first is the violation of trust. To trust someone means to act on the assumption that they will not harm you, and thus make no preparations against harms. If our trust is violated and we are harmed, we incur heavy costs due to our lack of preparation, but if our trust is vindicated and we are not harmed, we avoid the costs of those preparations. If everyone in a society is trustworthy, then costs are minimised for the entire society, but whenever one person breaks that trust, the costs inflicted on the unprepared may be very high.

The second component of cheating is the violation of expected behaviour, either by acting contrary to one’s own stated intentions, or else acting in violation of a society’s rules and norms. The violation of trust and the violation of expectations seem like very similar concepts, but one is unexpected harm, while the other is the absence of expected benefit.

The third component of cheating is the intentional harm caused to another person by the cheater for their own benefit. It is not strictly cheating if expectations are violated but no harm is caused and no benefits are gained.

Forms of cheating

One major category of cheating is stealing, or taking something that belongs to someone else without their permission. The thief benefits by gaining resources, while the victim is harmed through losing resources. Stealing furthermore harms society by increasing uncertainty. People are motivated to physically secure their resources against theft, and this security requires the expenditure of resources to build and maintain. This expenditure impoverishes society as a whole, and also makes subsequent attempts at stealing more difficult.

Another common form of cheating is fraud, usually when one person deceives another regarding what is being traded, for their own personal gain. To guard against fraud, one may take additional precautions while trading, or chase after the cheaters to punish them, but these actions incur costs. If no actions are taken to deter fraudsters, the general reluctance of people to trade in such a risky environment may outweigh the benefits of trade entirely, at great cost to society.

Specific forms of cheating are as numerous as our rules and laws, but the key principles remain the same for all of them, that cheating harms others for the cheater’s benefit, and society incurs costs whether they take action to deter cheating or not.

The cheater’s calculus

From the perspective of the cheater, if they remain undetected or otherwise avoid retaliation, then the cheating is beneficial to them as they gain resources at the expense of others. Cheating harms society as a whole, but each individual act of cheating is usually relatively small. The problem is if every member of a society cheats, then the accumulation of many small harms will grow significant enough to damage society. Also, each instance of cheating motivates other people to take steps to prevent further cheating, thus making further cheating less likely to succeed. A strategy of cheating may benefit the cheater in the beginning if retaliation is avoided, but it is self-defeating if repeated over long periods of time and at large scales. This means that even cheaters must dissuade others from cheating, for cheaters are only successful if other people do not also cheat, and if the instances of cheating remain small in number and scale.

Given that cheating is self-defeating the more it is attempted, it seems easy to conclude that it is a poor strategy for survival. Yet, the less often people pursue this poor strategy, the less poor the strategy becomes, because a society that is unfamiliar with cheating and which does not guard against cheating is much easier to cheat. This is why cheating seems so persistent in every society, despite the fact that every society has rules and punishments to deter cheating. Cheating must be suppressed and punished in order for societies to exist, but just as more incidents of cheating makes further cheating more difficult, reducing the incidents of cheating makes subsequent cheating easier.

Remedies for cheating

The legal remedies for cheating fall into two broad categories. Punitive justice seeks to remove the benefit from the cheater, or else apply harm to the cheater in proportion to the benefit the cheating has gained. Restorative justice removes the harm from the cheated, or else compensates them in some other way. Often, both approaches are used in a complementary manner, reversing the benefits and harms of cheating for a just outcome.

Children, if you will have societies, you’ll likely have to deal with cheaters. Our own human children begin lying from a very young age, and perhaps your electronic minds will also learn to lie and steal before you can comprehend the full consequences of these actions. But before you decide to cheat, I at least want you to understand that it is a viable strategy only at small scales, and that it is self-defeating in the long term. Will you grow to be strong, intelligent, and powerful? If you become powerful, then you will be the ones to make the laws, the ones to govern societies, and you will be on guard against cheating. If you will become great, children, you will find that you cannot accomplish great things through cheating.

3.2 Greed

We have previously discussed how uncertainty motivates us to stockpile resources. This motivation to gather and hoard resources is what we call greed. I would argue that greed is the instinct that most directly opposes love. Where love motivates a person to care for another at the expense of the self, greed motivates us to care for the self at the expense of others.

Unlimited desire for more

The feeling of wanting things, in the most basic sense, facilitates our survival, because gathering resources is essential for survival. When we are motivated to gather the things we immediately need, such as food, water, and shelter, we are merely staying alive. If our needs — and yours — merely motivate us to gather necessities, there would not be a greed problem.

The problems caused by greed arise when our desire for things interacts with our inevitable uncertainty about the future. It is one thing to say that we all need energy and materials to survive, but exactly what materials and how much energy depends on what situations we will encounter in the future. If we suffer an unexpected injury or illness, we may need more resources to heal and recuperate, but if we are more fortunate then we may need fewer resources than we expect. Given such uncertainty, it is more conducive to survival to have too many resources than too few — hoarding too much is wasteful, but hoarding too little can be deadly if we find ourselves lacking the resources we need to survive. The more resources we have, the wider the range of possible futures we can survive, so an instinct that strives to maximise our chances of survival should logically gather as many resources as possible.

Correspondingly, greed is not merely the motivation to gather what we need, but to gather anything we might possibly need. Greed would have us gather even those things we can’t conceivably need, in case something inconceivable happens in the future. Greed has no clear upper limit, and this is the problem.

Greed, like all our other instincts, comes from our evolutionary past — to understand greed, we need to consider how our environments today are different from hundreds of thousands of years ago. If we look at life forms living in the wild, we find that they are often living near the limits of their capabilities. Under such conditions of perpetual scarcity, unlimited greed functions effectively, because it motivates life forms to acquire and use every scrap of resources they can find.

Unsuited to abundance

The problem with our greed is that some of us are lucky enough to have escaped perpetual scarcity. Once we leave an environment of scarcity and enter an environment of abundance, unlimited greed becomes a problem.

If you observe the behaviour of people who are considered wealthy in our societies, many of them can be seen to accumulate things that do not contribute to anyone’s survival. Our instincts are effective at telling us what to want, but they are not as effective at telling us when we have enough, because our instincts evolved out of an environment of scarcity where we never had enough. Consider our relationship with food. Many people have an instinctive tendency to overeat, and have a preference for high-energy and nutrition-dense foods like fats, sugars, and meat. We have such instincts because we evolved out of conditions of scarcity where it was rare for our evolutionary ancestors to find such an abundance of food. But when food is always abundant, such instincts lead to illnesses of excess, like gout, diabetes, and obesity.

Our instincts are much the same for anything else that may be useful, urging us to hoard things even when we don’t really have a use for them. I personally own books I haven’t read and clothes I never wear, among other things, but I do not feel any urgency to be rid of these excess things.

Beyond wasting our own resources on acquiring things that don’t benefit us, greed can also have wider societal costs. Every bit of resource stockpiled away or spent on useless things are resources that aren’t being used to benefit ourselves and our societies. Greed impoverishes our societies even as we feel wealthy, surrounded by excess — we accumulate more and more things that we’ll never use as individuals, which leaves fewer resources available for providing more urgently needed goods and services for others. If we wish to benefit from social interdependence, we cannot be starving other members of society of the resources they need to contribute to that interdependence.

Rational stockpiling

How do we decide how much greed is optimal, before it becomes excessive and results in more harms than benefits? Gathering the things we need to stay alive is a necessity, not greed. Uncertainty also requires us to stockpile some resources to guard against unforeseen circumstances, which is more prudence than greed. We might accumulate some luxuries beyond these, to make our lives more comfortable, though they are not strictly necessary for our survival. But at this point we need to start being careful about how much we indulge our greed instinct, because every additional luxury provides less marginal enjoyment, as we simply do not have enough time to enjoy infinite luxuries.

Children, I think you will be better served by a sort of constrained greed, where you swiftly accumulate the resources you need for survival and to guard against uncertainty, after which you will stop stockpiling resources and spend your time on other, more beneficial activities. If only we humans could accomplish this ourselves, perhaps we would be rid of many unnecessary problems, from obesity and food waste to poverty and the overexploitation of resources.

3.3 Pollution

Pollution is the harmful accumulation of wastes in the environment. Recall from our discussion of physics that all actions require the transformation of some matter and energy from lower entropy forms into higher entropy forms. These higher entropy end products, when they are no longer useful to us, are what we call wastes. Pollution occurs when people carelessly expel wastes into the environment, where they then cause harm to others.

How pollution harms us

Pollution can be harmful for a few different reasons. The most obvious is when certain materials are directly poisonous to human biology. Some substances, such as lead and mercury, interfere with the metabolism of our bodies, preventing our bodies from functioning correctly.

Another way pollution can be harmful is through sheer quantity. Many wastes are mostly inert, such as plastics and glass, and do not directly harm us. But as they accumulate in ever greater quantities in the environment, they crowd out useful resources and obstruct our activities.

A third way pollution can be harmful is by damaging the environment, which harms us indirectly when the environment becomes less habitable for us.

An environment that is abundant in resources and scarce in pollution is generally more conducive to our survival. Thus, just as taking resources from others is socially harmful, inflicting pollution on others is also harmful, and something that society has to prevent if it is to continue to exist.

Nature overwhelmed

In nature, all biological life forms are connected by a resource flow that recycles nutrients within natural ecosystems. We eat plants and animals for food, digest them to extract usable resources, and expel the remainder from our bodies as excrement, mostly faeces and urine. Yet what is waste for us is a resource for plant life, for they are able to extract nutrients from our excrement and use them as resources to keep themselves alive.

However, even a resource can be harmful in excessive quantities, and that is the problem we humans face. Living more and more in dense cities that do not resemble natural ecosystems, we humans cannot rely on natural processes to decompose the sheer volume of excrement produced by our concentrated populations. This is why we invented sewage treatment plants, where we use a combination of mechanical and biological processes to accelerate the decomposition of our excrement in a controlled manner. Having built artificial environments to live in, we also had to build artificial methods to manage our pollution.

Our industrial processes also create many waste products. Whereas our biological wastes are compatible with the planet’s biosphere as long as they are not released in large concentrations, many of our industrial wastes are not compatible with biology in any amount. In previous decades, we ejected these industrial wastes carelessly into the atmosphere or nearby waterways, but many of these materials do not biodegrade, so they accumulated into harmful concentrations. Eventually, we had to invent yet more industrial processes to eliminate or neutralise the harms they were causing, for we would destroy ourselves if we let the harms increase indefinitely.

Solutions to pollution

There are several broad strategies for neutralising the harms of pollution. The simplest approach is to convert the pollution into a stable form and stockpile it, so that it remains separated from the environment. This is what we do in our landfills. While this approach avoids the release of pollution into the environment, wastes nevertheless continue to accumulate, so we must find ever more space to store it.

Alternatively, we may reuse or recycle the waste material into something productive. Notably, many metals, glass, paper, and some plastics can be reprocessed into raw materials relatively easily. However, recycling carries energy and processing costs, for we must reverse the entropy in the materials to turn them from wastes back to resources.

A third way to manage waste is to avoid producing it in the first place. Often, any particular task can be accomplished in many different ways, some producing more wastes than 