5....This conservative stance still leaves plenty of room for all sorts of speculation about the nature of alien beings.

• Alien bodies might roughly resemble our own; they might stand upright on two legs, grasp with two hands, and have a head with two eyes. But the alien physique could be different. A four-footed being might manipulate objects with a mane of tentacles. Poisonous aliens would not need efficient locomotion, and therefore might evolve almost any physique. An intelligent being might even be naturally immobile, and master its environment by using signals to control various mobile forms of non-sentient life. Aquatic aliens might use their tentacles and intellects for growing underwater homes and developing aquaculture. Alien symbiotes or parasites and hosts evolving together could ultimately have bodies with naturally replaceable sections.
• Then again, aliens might spread their culture to Earth by seeding it with "translations" of themselves; genetically engineered beings physically and chemically indistinguishable from humans, but carrying within their genes a combination of predispositions and unlearned information that would drive them to seek each other out, and conspire to express alien values in a human cultural context. Humans may be too superficial to understand that, despite all that would be lost in such translations, what remained might still have value for their authors.
• Since information can be transmitted, the number of bodies per individual might vary from world to world.
• Since multiple personalities might not be pathological for every sentient species, the number of individuals per body might also vary.
• As portrayed in more than one science fiction story, the minds some intelligent beings might exist as information stored in a form that could be transmitted, when necessary, from one body to the next, assuming that all the bodies in question had the appropriate structures for transmission, reception, and storage of such information.
• Chemical dissimilarity between humans and extraterrestrials would probably make their respective proteins mutually inedible, and rule out predation and procreation between sentient species. The same factor might make their microbes harmless to us. Our bodies might provide no medium for the growth of their germs, and visa versa. Our soil, contaminated as it is by earthly organisms visible and microscopic, might be useless for the cultivation of their crops, and visa versa.

Science fiction writers have set down hundreds of speculations about aliens more imaginative than these. So now we will turn our attention to some speculations that this writer has not heard before about how aliens might talk and think.

Many of our attitudes and beliefs that take precedence over common sense could be peculiar to our species. Aliens might have no conception of them. We in turn might have no inkling of the attitudes and beliefs that would make aliens seem oblivious to the most pressing realities.

Since small groups of aliens could travel farther through space than whole colonies, we might meet aliens individually before encountering large contingents of them. If so, the pitfalls of the naive standpoint illustrated here could prevent us from correctly evaluating their intellect or common sense.

It should be noted that non-sentient creatures in their natural habitats deviate from the dictates of common sense far less often than humans do. Wild animals tend to feed themselves, avoid danger, and perpetuate their kind dependably, unless physically prevented from doing so.

Far from ruling out intelligence, a lack of adequate caution and self-care among mature, alert higher organisms could be indicative of this virtue. Chowder-headed behavior could be common to all sentient life. Then again, intelligent species could vary in the reliability with which they display common sense. To Humanity, consistently sensible aliens would be alien indeed.

All the latter sentences are nonsense--except for beings who use sound as a metaphor for time and timing in expressing the following ideas:

• The silent prayer coming up in [a specific short time period].
• The ancestor's death was a long time ago.
• He jumps and grasps at the same time.
• This waiting is taking a long time.
• The thunder came suddenly.
• The running did not begin until [a longer specific time period] ago.

Knowing the context of this little game, and provided with enough simple examples, any clever person could catch on to the sonic time metaphor illustrated here. But remember how nonsensical the examples seemed at first, and how nonsensical they would still seem outside this context. Then remember how pervasive and elaborate English spatial time metaphors are. Then remember that we humans use more than one major metaphor to talk about abstractions.

What if aliens had dozens of major metaphors to work with, all foreign Humanity? What if they relied more than humans on metaphors taken, not from Nature, but from cultural references? Any alien discourse above the level of "The stone is on my foot," would then confront the translator with a monumental wall of apparent nonsense, whose dimensions could take lifetimes to fathom.

Perhaps a human child raised among both humans and aliens could understand and explain alien metaphors. Then again, human children might be innately handicapped when it came to learning an alien language.

Some comparisons might come more naturally to aliens than to humans, and visa versa. In that case, metaphor might prevent even a child raised part-time among aliens from acquiring adequately sophisticated self-expression in the alien language.

But let's be stubborn, and assume that alien metaphor would resemble our own to the precise extent that alien experience would. Let's suppose that being able to see what we see, walk as we walk, and pick things up and manipulate them as we do, would prompt aliens to adopt figures of speech closely analogous to our own. Even granted this chauvinistic premise, alien metaphor could still be extremely difficult for humans to comprehend if aliens had experiences unknown to Humanity.

Non-human sensory powers could create vast experiential sources for alien metaphor inaccessible to human acquaintance. Consider aliens who could echolocate, see infrared light, taste and smell better than humans, deliberately transmit and receive pheromones, and perceive electrical fields or radio transmissions. A human child attempting acquire metaphors based on such experiences would be laboring under a sensory handicap.

14....Metaphor is not the only cultural factor that could hinder the erstwhile interpreter of alien communication. Aliens might define 'appropriate communication' in ways unheard of on Earth, and unfriendly to any humans trying to make sense of them. Even in familiar human cultures, the definition of acceptable forms of contact may have little apparent basis in reason. For instance ...

• The practice of meeting in restaurants and dining rooms in order to converse is patently unreasonable. Eating and talking interfere with one another. Both operations would be more efficient if performed at separate times. Yet, for countless American humans, eating and talking in the same sitting facilitate both reproductive and economic success. Hence the continued popularity of romantic dinners and business lunches.
• Parties are similarly puzzling from a logical point of view. What are they for? They are not needed for stimulation; appreciating art and avoiding exploitation are both more nourishing for the mind. Parties are not needed to affirm one's social affiliations; this can be accomplished by hugging, kissing, shaking hands, signing agreements, and a host of other activities more frequent and less expensive than traditional celebration. Parties are redundant with respect to the commemoration of events, which can be noted on most calendars. Parties are especially unnecessary for communication, as their participants tend to either poison their nervous systems with drugs, or put too much food in their mouths. The exact significance of parties is unclear; one searches in vain for a consistent theme uniting birthdays, wedding receptions, wakes, Christmas, Friday, and the distribution of brand-name plastic containers. Yet humans not only consider partying purposeful, but exalt it as one of the most desirable forms of social contact.
• Although differences in social status could be advertised simply and cheaply with different kinds of hats or tattoos, citizens of "advanced" nations prefer absurdly resource-intensive methods, such as varying the wastefulness involved in the construction of different makes of cars.
• While animals are either social or solitary, humans spend their days fleeing to and from both privacy and society. We have to go out, or we feel lonely. We have to come home, or we feel harassed. Every day, we clog our freeways to sustain this constant flight. Alternate approach and avoidance characterize communication with both co-workers and family. Why can't we make up our minds?
• Finally, no fact of expediency or Nature dictates that the prevalence of violence should increase with a society's economic complexity. Yet it consistently does in human nations everywhere, not only as a means of acquisition, but also for communication. Modern humans shoot, beat, and maim not only for robbery and war, but also to make political statements, give vent to psychiatric problems, express distaste for certain groups, protest working conditions, instruct children, and assert the desire to be taken seriously.

In the face of all of the unfathomable deeds performed in the name of communication by the cultures most familiar to us, we can make no definitive assertions about what aliens would consider appropriate in the transmission of sentiments and ideas. Would aliens greet us by buzzing our atmosphere with floating lights for a century or two? Would they announce their presence by dismembering local fauna? Would custom restrict them to non-verbal interaction with anyone outside their own species? Would they hide themselves collectively, as we hide our naked bodies individually? Far from being ridiculous, such questions are probably too conservative. Non-human ideas about appropriate interaction could prevent any human--child or adult--from acquiring even a single word of alien language.

15....Then, there is science. Since the natural sciences make the greatest number of references to truths about the universe that hold for all rational beings, and since science depends on mathematics whose application is equally valid for all technologically advanced cultures, it seems reasonable at first blush to assume that discourse on the natural sciences would be the next best thing to a universal language, providing humans and aliens with a completely common set of referents with which to teach one another their symbolic systems. However, several considerations cast doubt on this optimistic vision.

• First, advanced physical science is grounded in references to unpicturable entities, forces, and dimensions far removed from everyday perception. For instance, none of us can witness quarks, electrons, or neutrinos. This makes advanced physical science irrelevant to many of the topics that language is used to discuss. There is no way to use physics equations, even those that humans can understand, to say things like "Take us to your leader," "We're lost," or "We would like to annihilate your species." Natural science is too specialized to serve as an interstellar rosetta stone.
• Second, nothing guarantees that humans could decode alien scientific language even if their science resembled our own. Humanity has yet to contrive any symbolic system with a proven ability to express any and all abstract scientific and mathematical ideas to listeners and readers who are wholly ignorant of that system. Such a code might not exist. If it did exist, it might be easily understood only by beings significantly more intelligent than humans.
• Third, science might not provide a common set of referents for two species to discuss if alien scientific theories were more advanced than ours. It is doubtful that Galileo could have understood relativity or quantum mechanics armed only with the concepts of his time. The theoretical forces postulated by alien science might be just as unknown and incomprehensible to today's earthlings. Discourse about them would be less easy to decipher than other alien messages, perhaps for more than one reason, as we shall see.

Differences between alien and human neurology that could hinder communication between sentient species have already been mentioned or hinted at a number of times above. Let us now consider the possibility that representations of the natural world might vary across sentient species not only at the level of language, but also at the level of neurology.

The extraordinary advancement of science in this century has lulled many of us English speakers into believing that the human brain has no inherent limits--that only the burdens of history and finite time prevent us from attaining a correct and universal account of reality--that human intellect, considered apart from emotion or appetite, has no natural weaknesses that condition its perception of the world.

If the mind were visible and tangible, the absurdity of this bias would be apparent to everyone. Consider the human hand. Faced with the potential infinity of objects it can create, some fool might claim that nothing could limit its powers of manipulation. Yet the hand is frail, finite, and peculiarly configured. An engineer could easily design tools unsuited for it, even basic tools needed for the manufacture of all other devices. Such tools might confront the fingers with an impossible reach, a requirement for more or fewer fingers than we have, or a hopeless overestimation of human grip strength. With such tools literally beyond Humanity's grasp, alien hands might construct artifacts that do the same work that ours do. Who is to say that analogous considerations could not apply to alien brains?

Information about the relative infirmities and strengths of the human brain might suggest ways in which alien cognition could differ from our own. For example, consider the partial specialization of our two cerebral hemispheres.

One contains the best sites for language processing, while the other is better at processing spatial information. Sure enough, human language is infirm when it comes to describing sights. What painter, however skilled, could reproduce a detailed photograph from a written description alone? For humans, a picture is worth a thousand words.

The same might not be true for aliens, whose language and spatial reasoning centers could be more integrated than ours. A nervous system capable of integrating visual and verbal information, such that it could command a naturally acquired symbolic system that does the work of both language and digitized photography, could contain an intelligence comparable to our own. Yet our psycholinguists might strive in vain for years to understand the expression of such a strangely integrated way of thought. Humans researching such alien minds could be conceptually hobbled by their own partly split brains.

Representation of reality at the level of neurology might vary from human norms in other ways. For example, what if alien brains were much better suited than ours at applying the strange concepts of advanced science to their everyday experience? Quantum mechanics and general relativity, which lie beyond the grasp of this writer and most other humans, might be easy to picture for another species. If this were reflected in their everyday language, we might despair of understanding much of what they have to say, even if some of it could be translated into a human tongue.

Who knows how alien thinking might differ from Humanity's? Pairing concepts into opposites seems more natural to us than arranging them in threes. Attending to the present is easier for us when we forget the past. The geometric simplicity of our artificial objects is easier for most of us to understand than the fractal riot of natural forms. These are ideas about the way we think, not the constitution of reality. Perhaps aliens could deal just as effectively with reality as we do without sharing these habits of thought. If the alternative habits proved inconceivable to us, would they therefore be impossible for all species, or just ours?

There is no guarantee that the manner in which aliens experience and conceptualize their emotions would bear even a superficial resemblance to our own.

• An alien might characterize its own responses as reflecting the fluctuations of a single feeling--let's call it "juice"--the fullness of which is experienced only by becoming one with others, a satiating dose of which can be obtained from physical comfort, a sudden depletion of which provokes immediate and drastic action, and the absence of which prompts unresponsiveness or even premature death.
• For some aliens, the experience of emotion might be mediated through perceived physical sensations. Negative emotion might be perceived as an abdominal pain or a bad smell. Positive emotion might be perceived as sexual or gustatory sensation. Environmental and social context would enable such aliens to intellectually distinguish their emotions from sensations with physical causes.
• Similarly, emotional awareness in the alien mind might be mediated by hallucinations, originating genetically and common to a whole species. For such aliens, reliably distinguishing emotions from external experiences would be a conceptual skill acquired in the course of maturation. Subjectively, the alien might feel the pull of love as a horizontal version of the pull of gravity. Aliens might distinguish anger from fire only because anger has a different color, and leaves no actual charring behind it. The irritation of boredom might be experienced as literal dripping from the ceiling or sky, prompting the alien to fidget or leave.
• Alien emotions just as "intangible" as ours might still be exotic by human standards. Consider aliens whose emotions were all compatible with one another, and often combined. The fine line where joy and suffering converge in Humanity's heart might be a ten-lane superhighway in the mind of another sentient species. These beings might thrill with their every rage, savor the peace of their grief, and simultaneously mock and revere the lives sacrificed for their well-being.

  Some humans might label these aliens as pathological. Other humans might credit them with unusual closeness to reality, because beauty and savagery are mixed in Nature, as well as our aliens' minds. Still more humans might regard these aliens as absurdly distanced from reality--indistinguishable from TV spectators in their equal hunger for tragedy and love. But such interpretations could never do justice to the primitive and ultimately ineffable emotional experience of the alien young. Lots of emotions, none of them opposite, all of them compatible. Imagine a baby who, when hit, does not cry, but reaches for a pin to challenge the offending hand, driven by rage and playfulness working as one in its soul.

• Conversely, aliens might experience their emotions as rigidly separated; all mutually incompatible. While retaining a continuous memory, an alien might otherwise change its entire personality when switching from feeling to feeling. Each emotion would constitute a role. While humans think of their emotions as subjectively unanalyzable, like tastes and smells, our emotionally compartmentalized alien might analyze each of its emotions into long lists of things to do and believe that constitute the feeling. Although humans hardly think about the times during which they are not emotionally aroused, the beings described here might identify a specific periods of emotional rest, during which their activities are minimal.

  All this might seem odd to us earthlings, because our feelings are often mild or incidental, and may or may not be appropriate to the current situation. But aliens for whom each emotion was a different way of living would have no incidental feelings, any more than humans would make incidental changes of clothing during casual conversation. Our aliens would also have a large stake in the appropriateness of their emotions. If anger were like changing into a soldier, affection were like adopting a relative, happiness were like playing the convivial host, and regret were like becoming a monk, one's feelings would always have to be appropriate as a practical matter.

  It might not be possible for these beings to experience mixed emotions like bittersweet. For humans, such mixtures give occasion for a wistful pause. For aliens whose emotions are distinct roles, attempting to meet the demands of Love and Loss simultaneously might constitute a perverse duplicity or mental defect.

• We humans are accustomed to the fact that our emotions are not always appropriate to civilized situations. Anger evolved to combat dangerous animals must now be stifled to accommodate friends and co-workers. Laughter once directed at the mortal plights of others must now be tamed by ethics. Lust once satisfied informally must be controlled to preserve our social organization and genetic health. We know that this discipline is necessary. We come to identify with it as we mature. Yet no matter how responsible we are, our prehistoric emotions will not die. Each of us must take the time to relax our emotional control. Each of us feels so constantly at odds with the demands of civilization that we periodically flee into solitude or intimacy. Alone or in pairs, we must all escape the crowd, and let our feelings peek out from behind our civilized selves.
• But what about beings whose emotions were well suited to the demands of civilization? What would such people be like? Metabolically, they might compare to Humanity as tugboats compare to faster vessels; less speed, but more power for sustained effort. Their emotions might be correspondingly better suited for a daily grind than for life in the wild. They would not be passionate by human standards, but their feelings would last much longer than ours, being better suited for the protracted timetable of intelligent group effort.

  Their panic would be slow and shuffling, but their enduring conscientiousness in the face of insidious threats would put Humanity to shame. Their rage and wrath would be too tepid to threaten one marauding predator, but the machinations of their smoldering rancor might eventually extinguish an entire species. In their joy, they would resemble blissful elderly couples, still healthy and married after many years. In their enthusiasm, they would resemble the acolytes of an ancient cult, tireless and preciously exact in the performance of a weeks-long ritual. In their spite, they might all be chess masters, thinking ten to twenty dirty deeds ahead.

• The supposition that aliens would have emotions seems ever more reasonable as one contemplates Humanity. People who repress their emotions usually suffer for it. People who lose some emotional capacities to brain injury generally become unmotivated and useless to themselves. Although we are accustomed to thinking of emotion and intellect as opposites, some excitement is needed for study, travel, and other activities that broaden the mind. Most of our accomplishments occur in search of some emotional payoff or other. One could even argue that greed, pride, love, hate, and fear qualify as historical forces.
• Yet aliens might do without emotions, if, unlike Humanity, they were naturally driven to obey and realize their values. Such could be the case for aliens who conform to Nietzsche's description of the ultra-individualistic, ultra-aristocratic Overman. It is a rare person whose values become causes worth any sacrifice, but in the mind of our Nietzschean alien, feelings might be identical to choosing one's own causes--to nobly die for, to callously slaughter for, to pursue with the last ounce of one's vitality. At the opposite extreme, a sentient creature born to a planetary hive, devoid of individuality, might also lack emotions in the human sense, obeying only collective imperatives.

Values might serve as feelings for many other types of beings. While no theoretical consideration prevents machines from having emotions, an artificial person powered by fission would not need adrenaline, and its programming would probably reflect more useful dictates than those of passion.

Any society fitting this description, no matter what its ideology, would have to institute a system of rules that specify what individuals must do in a way that psychologically reconciles private desires to the demands of public need. Let's call such systems ethical. Such a system might begin as a list of things one must do or refrain from doing, and later be supplemented by a set of principles.

2....Ethical rules and principles are delineated by emotions as well as public needs. For any sentient species possessed of them, emotions would determine the range of behaviors one might expect from individuals, and make the successful institution of any given ethical rule or principle more or less probable.

A prohibition against harming infants is consonant with the emotions of beings who reproduce slowly and psychologically bond with their helpless young. A rule dictating the use of infants for nourishment in times of famine is less likely to be instituted by the same species. However, another species that reproduced quickly and bore independent young might embrace this alternative to starvation.

It seems clear that some ethical principles are instituted in nearly every human society, partly because some public needs are accurately perceived by and common to almost all cultures, and partly because some human emotional responses spring from biology, and so have a universal influence on ethical thought. For example, incest taboos prevent inbreeding and preserve kinship structures in most cultures, and the prohibition against murder is consonant with the universal, geologically ancient fear of mortal injury.

3....The claim that ethics are institutions demands at least a rough explanation of what kind of institutions they are. Ethical systems make demands on our personal conduct and theoretically apply to all members of society, like the law. But the power to interpret ethical principles and make moral judgments is dispersed throughout society, like economic spending power. Even in cultures that give an elite person or group the final say on ethical matters, moral authority is still dispersed among nosy friends and relatives, people who raise children, and anyone facing a moral dilemma.

The power to invent ethical principles may or may not be dispersed. At one extreme, a single person could go up to a mountain and come back with a complete system of ethics and law allegedly written by a deity who threatens to destroy all those who disobey. At the other extreme, the development of ethics might entail many interpretations of the teachings of numerous sages over time.

All this dispersal poses little threat to the ethical rules that society requires to survive. Uniformity in emotion and accurate perception of public needs are sufficient to maintain a fair amount of moral consensus in any given society. Only isolated and short-lived groups such as cults would institute complete relaxations of crucial rules like the prohibition against murder. Furthermore, information and persuasion that promote moral consensus can spring from various sources, such as elders, churches, political groups, sages, scripture, philosophy, and folk wisdom.

4....Since ethical systems are so beneficial and pervasive, the fact that people often disobey them needs to be explained.

• Obviously, the private desires that make ethical systems necessary can sometimes be stronger than the desire to do good.
• More generally, a society's promotion of ethics might be defective. The absence of credible moral authorities, widespread public emulation of a socially parasitic power elite, or a general perception that society will disintegrate no matter what anyone does, could prompt ever larger numbers of citizens to be ever less committed to obeying ethical rules, to the point where the perception of public needs becomes irrelevant to personal conduct, and the avoidance of punishment and quid pro quo become the only principles obeyed. Hence the term 'ethical decline.' Far from being intuitive or spiritual, this concept is every bit as intelligible as the idea of economic decline. As for societies where the principle of quid pro quo has replaced moral duty, our prisons show that they must be ruled under the gun at great expense.
• Some people will disobey defective ethical rules. For instance, ethical rules that benefit a minority at the expense of the majority inspire disobedience if the demands of the minority are too onerous, or if the populace becomes too well-informed. More on this below.

5....Also requiring explanation is variation of ethical rules across societies. If ethics fulfill social needs common to all societies, why do humans have so many disagreements about what is right and wrong? Also, why do ethics change? Sometimes, defective ethics are the reason. An ethical rule or principle can be called defective if it fails to contribute to social integrity, or has a destructive effect on part or all of the society in which it is instituted. Defective ethics may arise from the fallibility of rational beings or from the exploitation of people. Other sources of variation in ethical systems are necessary and unavoidable, including the need to assert cultural identity, and the differing circumstances in which societies find themselves.

6....The fallibility of rational beings could insure the existence of the following kinds of ethical defects:

• Some ethical rules and principles would reflect inadequate understanding of the objects of public need. For example, some societies might demand fasting every few days to bring rain, or adherence to supernatural belief to enhance public order.
• Some ethical rules and principles would exist to satisfy wholly imaginary needs. For example, a society could attempt to attract benevolent spirits by making necktie-wearing a moral imperative. Alternatively, witch hunts could be instituted.
• Some societies might simply fail to formulate all of the ethical rules and principles they need. Empty rhetoric notwithstanding, America has little in the way of environmental ethics, despite our pressing need for them. We consider it practical to control pollution, but we do not consider it morally imperative to do so. We do not despise or punish polluters as we do drunk drivers, in spite of the fact that a polluting industry can kill more people than a drunk driver can. Institutionalized denial or ignorance of socially noxious conditions may account for such ethical failure. Generations of juvenile delinquents created by child abuse can testify to this fact.
• Some societies might attempt to institute ethical rules to which individuals could not reconcile themselves. For example, a rule that no one should have sex before the age of twenty-six would do much to prevent disease and repair our society's kinship system. However, a large percentage of any human population would not follow this rule. The draconian measures needed to enforce it would tear society apart. A more likely consequence of such a rule would be public lip-service and private disobedience. This hypocrisy would result in the perpetuation of the very problems that the rule was designed to eliminate. Without public acknowledgment of the rule being universally ignored, the society would not institute more effective alternative rules.
• Since all societies are fallible, and different societies are likely to make different mistakes, fallibility is one reason why ethical systems vary. Similarly, as a society moves from one set of ethical mistakes to the next, its ethical system will change over time.

7....Since ignorance is an important source of our fallibility, advances in human knowledge have prompted ethical change. Human sacrifice may have seemed right for people who believed it necessary to appease the god who caused Spring to come. Whipping crazy people may have seemed right for people who believed in demonic possession. Beating children may have seemed right for people who thought that this correction was necessary. Now we know better, so the relevant ethics have changed.

Differences among cultures in accumulated knowledge will produce corresponding differences in ethical systems. The ever greater accumulation of knowledge within a society could theoretically lead to ethical progress, entailed by the elimination of ethical rules founded on superstition. But in practice, the ethical progress one might expect from the advancement of knowledge is wiped out by the power and consequent temptations that new knowledge creates. So in America, for instance, no one wants to burn witches anymore, but the majority accepts burning and defoliating countries who won't play ball with our corporations. This brings us to the next factor that can make ethical systems differ.

8....Human beings are inherently exploitative. If we were angels, we would exploit only things. None of us wishes to be exploited, so all of us could agree in principle to prohibit the exploitation of people. Unfortunately, exploiting people gains economic utility as societies become more economically complex. Sure enough, most human ethical systems allow the exploitation of people, but differ from one another and change over time when it comes to who is permitted to do the exploiting, in what manner, and to what degree. In one society, the clergy gets inordinate police powers. In another, landowners get to enslave people. In still another, the military enforces the use of other societies for raw materials and cheap labor. So it is that each society's ethics might in turn emphasize piety, property rights, and patriotism.

A large agrarian or industrial society can remain stable and yet allow the exploitation of even a majority of its people. In fact, this state of affairs has characterized all agrarian or industrial societies from ancient times across radically different cultures throughout our world. But the economic usefulness of exploitation eventually leads to its escalation, which weakens society in all too familiar ways. Societies become less stable as the rich get richer and the poor get poorer. Chronic tensions erupt between the victims of exploitation, who hate their mistreatment, and the perpetrators, who perceive the demands of the oppressed as excessive. Riots, increased crime, and social disintegration result. Maximizing the exploitation of the public in any society entails keeping the public ignorant or misinformed, which compromises education and decreases a society's ability to exploit its own knowledge and adapt to its own technological advances.

Humanity's physical and intellectual uniformity helps limit the exploitation of people. Exploitative leaders must maintain their friendships and carefully limit public outrage; they do not have the option of quashing rebellion by trampling cities and burning the rebels with their radioactive breath. Some exploitative leaders imagine that they are smarter than the people, but they are not, and the mistakes that flow from their inflated opinion of themselves weaken their organizations and move their societies ever closer to revolution or chaos.

9....Fortunately, there are less odious sources of ethical variation and change, including the need to express cultural identity. Oddly enough, this universal human imperative can only be satisfied by having different rules in each society. Society A worships God X, eats bread only on Mondays, never brings clocks into barns, and esteems consistent concealment of the toes as a sign of decency. Society B worships God Y, eats anything other than dogs, insists on nearly continuous hat-wearing, and rejects all public and most private nudity except on beaches, where nakedness is perfectly okay. This writer will call such regulations "identity rules."

Identity rules can be defective. Some are incompatible with liberty, an ethical principle of unparalleled utility in reconciling private desires and public needs. Some identity rules cannot be changed, and therefore promote fear of innovation and reluctance to adopt beneficial foreign ideas and populations. Identity rules can also become symbols of social divisiveness, and even badges for groups that persecute others.

But identity rules can also be beneficial. Although many of them have no discernible function when considered by themselves, taken together, they can communicate a solidarity--a society-wide sense of trust and belonging--more fundamental than loyalty expressed in mere words. Furthermore, identity rules can inspire resistance to hostile outsiders, and enhance the perception of social continuity across time.

Some identity rules, in and of themselves, do represent practical ways of satisfying public needs, but serve to identify a particular society because they represent one of several equally viable alternatives. Monogamy can be facilitated by arranged or couple-initiated marriage. A society can remain stable with either, and can help to identify itself through its fidelity to one arrangement or the other.

10....Finally, ethical rules will vary or change when the circumstances of the societies in question vary or change.

• The freedom to accumulate, abuse, or dispose of private property as one sees fit in times of plenty is incompatible with the prohibitions against hoarding, misuse, and waste in societies facing cruel shortages.
• Monogamy is a wonderful way to preserve kinship structures and organize families, but polygamy would have to be embraced if most of the males in a given society were killed off, or if the population decreased so much that genetic diversity had to be promoted at all costs.
• Similarly, the right of every adult to marry and reproduce with the person of their choice would have to be curtailed or eliminated if genetic diseases became sufficiently prevalent, or if Earth's population became dangerously high.
• As for capital punishment, one could defend a ban on this practice in a rich society by invoking a principle that the state should not kill when it does not have to. But in a nomadic desert society, too poor to afford prisons, such a principle would not rule out a death penalty, especially for the homicidally insane.
• The right of ordinary citizens to kill society's enemies on their own initiative, forbidden in times of stability, would be granted as a matter of course under an oppressive foreign occupation. Similar considerations apply to resistance against the tyranny of one's own government.
• The obligation to use any means necessary to prolong the lives of the sick and dying also varies with a society's circumstances. Prohibitions against mercy killing and neglect of the ill would inevitably be relaxed in post-apocolyptic environments in which even the care of the able-bodied would be a struggle.
• Be any of this as it may, some behaviors are noxious no matter what the situation, and ethics that permit them are defective in all societies. Rape and torturing five year-olds come to mind as behaviors that are useless as well as noxious in all circumstances.

11....So at last we come to the ethics of non-human intelligent life. If one accepts the kind of assumptions made about ethics here, it follows that many factors influencing ethical systems on Earth could vary considerably from world to world, and make alien ethics differ from our own. In the examples below, some common rules will be used to illustrate such differences.

12....Even if similar to our own, ethics in an alien society might be conceptualized and promoted in ways unfamiliar to our species. Although this writer maintains that ethics are institutions evolved to influence people, the fact that other writers can disagree shows that ethics need not be conceptualized in the same way by everyone. For some humans, ethics are rules to live by. For others, they are commandments from God. For others, they are a priori truths. For aliens, who knows?

• Ethics might not be considered distinct from law. The most private conduct might be legislated and specified in a legal code that all citizens consult. Conversely, what we would call legal authority on Earth might be dispersed along with moral authority on another planet. For example, parents and neighborhoods might govern all conduct whose consequences were confined within their spheres of influence.
• Ethics might not be considered distinct from esthetics. Social beauty might be sought for its own sake, like mathematical beauty or the balance in an Asian garden. Private desires could be reconciled to ethics in the service of beauty by means of artistic analogies--one's own desires are permitted expression when they bear the same relationship to the social order as a leaf has to the whole plant. Like some existentialists, our beautiful aliens might articulate their morality only in principles, eschewing specific moral rules because there are no hard and set rules for creating beauty.
• As the law and ethics are created and promoted in distinct ways on Earth, what we would call various aspects of ethics might be considered separate topics and distinct institutions by an alien species. For example, other-regarding and self-regarding obligations might be separated in the alien mind, such that separate sets of authorities might create and promote rules concerning each. One might require strict adherence to a list of rules; another might require intuitive understanding of one's inner harmony. One might be viewed as situational, and another might be viewed as absolute, by the same beings.
• Instead of being promoted by teaching and role modeling, ethics might be transmitted through forms of influence communication that we humans would liken to hypnosis. A conscience might even be a post-hypnotic suggestion: the false perception of an actual still small voice, triggered by one's own good and bad behavior.

14....Some alien ethical principles might resemble our own in a general way, but differ markedly from human ethics in the specifics of their application.

• In aliens with the prerequisite anatomy, promiscuity might be defined as using the same set of genitals for more than one partner, rather than using a different set for each partner.
• Suppose an alien culture had no human concept of identity, and people were defined by assigned roles, with more than one person able to play the same role. Now consider another alien culture comprising individuals with more than one body apiece. In both these cultures, a single murder might necessarily involve the destruction of more than one organism. Alternatively, aliens for whom multiple personalities were not pathological might define as murder the use of psychological techniques to integrate the personalities or selectively destroy one or more of them.
• Definitions of stealing could vary across worlds, depending on the nature of property relations. The definition of the unit of ownership might vary from world to world. On Earth, things are owned by individuals, married couples, families, corporations, and governments. Extraterrestrial societies might have other units of ownership. Societies without families might be organized into "lodges," whose members own all things in common, but do not share their goods with outsiders without special permission or sale. Other units of ownership might include occupational groups, and arbitrary groups such as races and people born during the same time of year.
• The definition of ownership itself could also change from planet to planet. The control of certain goods might go to the person or group who uses them with the greatest skill, aplomb, or esthetic sensitivity. Perhaps all goods would be owned only by the individuals or groups who make them, and become common property after the deaths of these artisans. Custom might dictate that one owns only those things that one talks to on a regular basis. Alternatively, property might be defined only as livestock, pets, and other living things, with all inanimate resources held in common, or visa versa.

  The range of things that no one could own might also differ across worlds. It varies from culture to culture here on Earth, with some societies rejecting the concept of "land ownership" as an absurdity on par with "air ownership." The variation could be expected to continue across worlds. In an alien society, a person might claim title to constellations, and be compensated by artists who produced their starry images.

• False witness is almost always harmful; it causes grudges and serves as a pretext for persecution. The prohibition against it would be instituted on many worlds, if only because of the need to identify the true causes of problems, even or especially when those causes are people. However, the application of this principle might vary from world to world. Among aliens without kinship structures or reverence for ancestors, no one might object to false witness against the dead; successfully scapegoating the dead might be regarded as a legitimate means of facilitating forgiveness and harmony. Limited false witness might also be accepted among aliens who were psychologically capable of treating intangibles such as blame as exchangeable commodities.
• Ethical choices uncommon or heart-wrenching on Earth might be common on other worlds. Euthanasia might be common among sentient species who express and require less love than humans. Abortion might be common among egg-laying aliens--as common as making omelets. Suicide, instituted for social and ethical purposes in few Earth societies, might be the honorable way out in all nations on some other planet.

14....Some of our ethical rules might not logically apply to certain intelligent species, even if our other rules did.

• Consider aliens for whom sex was completely impersonal, such as those who spawned en masse in water and had planktonic young. Alternatively, consider aliens biologically driven to have only one mate for life. Prohibitions against adultery would be meaningless for such beings.
• Aliens psychologically incapable of killing members of their own species would require no prohibition against murder.
• Some aliens might never develop the concept of individual ownership, obviating a prohibition against stealing.
• Among aliens who could see infrared light, and involuntarily displayed their every emotional nuance by dramatic changes in skin color, vocal register, and style of movement, the ability to lie convincingly might be so rare that a prohibition against bearing false witness would be pointless, or relevant only to bizarre circumstances.
• Aliens superhumanly tough and insensitive to pain might see nothing wrong with interactions that humans would regard as brutal.

15....Belief systems not found on Earth, and symbolic gestures not found on Earth, would give rise to ethical rules not found on Earth. On another world ...

• Superiority to animals might have to be proven by removing one eye.
• Obligations of pilgrimage might be so constant and pervasive that all responsibilities incompatible with travel would be rotated among passers through.
• All decent individuals might have to build a large cairn by hand, with one stone for each of the 3,333 Revered Ones.
• Hands that did bad deeds might have to be gloved.
• One might be morally obligated to raise a plant, and then an animal, before raising a child.
• All adults might be required to sleep surrounded by five lights that stand for the Five Martyrs whose deaths represented the Five Creative Principles of the universe.
• Decency might require, as a sign of loyalty to one's people, fluency in every mutually unintelligible ancestor of one's current language.
• Frank criticism might be permitted only in total darkness, and be immoral in other contexts.
• Owning living things or objects with painted or engraved eyes might be considered indecent.

The the list of behaviors that aliens might demand in the name of Deity, Decency, Identity, or principles beyond human ken is potentially ENDLESS.

16....Some alien ethical principles might utterly contradict the ethics embraced by the overwhelming majority of human societies.

• Yes, some aliens might be naturally and cheerfully promiscuous, and have their sex in groups of any number. Venereal disease would be a problem, but Humanity has survived more easily transmitted scourges, from pneumonia to bubonic plague. Quarantine and medicine could keep our alien libertines alive and doing what they do best.
• Aliens with no compunctions about killing and eating smaller members of their own species might need ethical rules that regulate the consumption of little ones.

Let's turn to a more general speculation, related to the exploitation of people. It is been argued above that physical and intellectual uniformity limits our ability to exploit one another. What about aliens who were not so uniform? What if the members of an alien race started out as small animals and grew continuously in size, strength, and intelligence until death? Imagine aliens who always became bigger and smarter with each year of life, whose brains continued to grow even as the decades wore on, and whose size differences reminded one of the size differences found among trees,. Let us suppose further that these aliens could live for a very long time, and that they were capable of surviving independently from birth.

Human ethics might be totally foreign to such a species. Avoidance of elders, alliance with peers, and exploitation of the young might be the only principles of personal conduct. It would cost the elite nothing to exploit little people. What pressure could humans bring to bear against a leader with the size and strength of a tidal wave and the mind of a god? How could preschoolers prevail against an adult the size of a house? An elder could physically trample the rebellious young, and outsmart them at every turn. The young could be lied to, stolen from, eaten for food, and abused in every way-- helpless to resist. Among the oldest group of peers in this society, alliance based on enlightened self-interest might result in a social harmony as beautiful as a sunlit forest. Like the trees in this forest, our elder aliens would grow, blissfully blocking out light and life from their smaller relatives at no cost to their tranquillity.

17....Some aliens might not need ethics. For example, consider the members of planetary hives, each devoid of individuality. With no private desires and no imperatives other than fulfilling their assigned functions, such beings would draw no distinctions between what they should do and what they want to do. If they attempted to learn a human language, they would struggle in vain to understand "rights" as anything more than an irrational pseudo-concept invoked to defend behaviors that do not embody total devotion to the collective and therefore do not make sense.

18....Some alien societies might enjoy greater success than Humanity in creating ethical systems with few defects. For example, some aliens might never exploit people. Some species might institute giving from each according to their ability to each according to their needs. Some species might, more often than not, treat others as they would like to be treated themselves. None of this excludes heated arguments, bad policy decisions, mistakes in child rearing, cheating so no one will notice, or the occasional evil individual. Aliens could be flawed in many ways, and still be far better than most people on Earth.

4....Interstellar contact between representatives of life-bearing planets might be extremely dangerous. Let us suppose for a moment that unknown regularities of chemical evolution insure that life would be chemically similar across worlds. This would make life-bearing planets treasure-houses of nutrients--sources of topsoil to invigorate ancient cultures that squandered this resource on their home worlds--sources of literal continents of food and medicine.

Unfortunately, chemical similarity among the biospheres in the universe could also make life-bearing planets home to infections against which visitors would have no natural immunity. With sufficiently long incubation periods, such infections could wipe out whole species whose astronauts returned in apparent safety from encounters with offworld life.

The need for interstellar quarantine might even dictate the elimination of interstellar travel. Perhaps our first encounter with alien culture awaits the day when manned spacecraft leave the solar system, only to be immediately vaporized by swarms of robot attack drones, programmed to protect the universe against the innocently genocidal explorations of our germ-ridden species.

Ironically, aliens who would impose such a quarantine would have to search for intelligent life. But they would not have to talk to us. If all our manned interstellar ships were vaporized upon passing Pluto's orbit, we would get the idea. Communication would only increase the risk of our finding out their weaknesses.

5....Even if voyages to life-bearing worlds were safe, Earth might have nothing to attract the jaded interstellar jet set. With only one native intelligent species, a filthy atmosphere holes in the ozone layer, diminishing wildlife, no interstellar travel of its own, and xenophobic air force yokels shooting at UFO's, Earth might be generally perceived as a stultifying, inbred, podunk planet--definitely not worth a ten-decade interstellar voyage.

6....In all seriousness, why would aliens visit us? The desire to meet new people and understand different points of view isn't even universal among humans! Only a tiny portion of us take the time to learn about other languages and cultures, and this mainly out of practical need--because the company wants work done overseas, because America needs spies, and so on.

7....What practical need would motivate an interstellar voyage to Earth?

• Not our mineral resources. These are not unique, and it is easier to mine smaller planets and asteroids, whose lower gravity is less of a burden to space flight.
• Probably not our biostuffs. These would probably be useless or dangerous to alien life.
• Not our technology. Any species capable of inter-stellar travel could not expect to learn much by coming to us.
• Not the enslavement of Humanity. Any species capable of interstellar travel could probably obtain unlimited energy from fusing hydrogen atoms, and build unlimited numbers of machines that could work better than slaves.

8....Scientific curiosity might prompt small parties of aliens to visit Earth. So might an esthetic appreciation for life-bearing planets. However, this does not mean that alien visitors would communicate with us. If they wanted to observe nations unspoiled by the knowledge of life on other worlds, they would have a powerful incentive to remain undetected.

9....If aliens came to Earth to contact human beings, their reasons would probably be ideological. They would have to believe that affecting our society through their information and/or presence would serve a higher purpose than mere expediency. Such purposes might include ...

• teaching us the creed that eliminated strife on their world, or their science, just to see what we could learn;
• saving Earth's unique wildlife by getting rid of all us pesty humans;
• learning the wisdom of Humanity, which must be a holy species, since we reside on a planet that orbits a sacred star;
• subjugating Humanity because we would make fascinating and beautiful pets;
• talking to us and evaluating our responses, so that they could study our psychology or laugh behind our backs at what the jarhead humans had to say.

But all this is probably too anthropomorphic. If aliens visited us for a higher purpose than expediency, we might never understand that purpose. We can't even explain some of our own ideals and concepts to each other. German gemutlichkeit. American classiness. Medieval honor. The true meaning of existentialism. The Tao, and its cousin Zen. The God of the Sufis. The gods of polytheism, whose images communicate principles that words cannot. Mere explanation is inadequate for the transmission of such concepts. Yet they could all seem easy to define in comparison to the ideas that might guide aliens to our world.

copyright 1999, from "Collected Essays of James S. Grossmann, Volume 1"