Human Life and Its Value: Would You Want to Be a Brain in a Cyborg?



Human Life and Its Value:

Would You Want to Be a Brain in a Cyborg?

Robert D. Anderson


If human life is a foundational human good, as some of us think, then its value cannot be strictly proven.  As a foundational good, it is an ultimate starting point in practical reasoning (“it is what I am finally striving for”), and as a foundational good, it is an ultimate resting point for the human heart (“in it I can find enormous fulfillment”).  But to maintain that human life is a foundational good that cannot be strictly proven to be such does not mean that its value can only be grasped by appeal to opaque intuitions, which some people claim to have but few other people seem to have, or by strident insistence that its value is just obvious.  Instead, the value of human life can be manifested by indirect proofs that back into a corner the person who denies its value and by dialectical considerations that lead to insight.  An example of an indirect proof is the reduction-to-the-absurd argument outlined in Joseph Boyle, John Finnis, and Germain Grisez’s Nuclear Deterrence, Morality and Realism.[1]  That argument says the denial of the goodness of human life entails a body-mind dualism which is untenable.  Why body-mind dualism is untenable has been recently argued in brief by Christopher Tollefsen and Robert George in Embryo: A Defense of Human Life[2] and at length by Patrick Lee and Robert George in Body-Self Dualism in Contemporary Ethics and Politics.[3]  Indirect proofs for the value of human life like that one, however, are not for the philosophically fainthearted, whereas this article is.  So, I turn instead to a dialectical consideration that leads to insight.

The argument that I will develop is a thought experiment.  Since it does something similar to Robert Nozick’s famous experience machine and it does this because it is a product of the reverse engineering of his thought experiment, let us recall and analyze the experience machine first.[4]

I. The Experience Machine

Suppose there were an experience machine that could stimulate your brain so that you had the subjective experience (thought, sensation, feeling, volition, and memory) of doing anything you deemed worthwhile.  You will not do anything but lie in, on, or near the machine and experience.  Do you want to hit the walk-off home run in the final game of the World Series, finally bringing a championship back to Chicago Cub fans?  You can experience what that is like.  Do you want to compose music like Mozart?  You can experience that too.  Any experience you can imagine is, in fact, available in the experience machine.  Moreover, so good is the simulation of experiences in the machine that you cannot distinguish those experiences from the veridical experiences. Would you be willing to plug in?  The right response (the reasonable response) is “no.”  We should, if we do not already, recognize that how our experiences feel from the inside is not the only thing we value.

In his 1983 book Fundamentals of Ethics,[5] John Finnis critiques plugging into the experience machine, and he explains how the experience machine experiment shows more than the negation: “pleasure or, more generally, desirable subjective states are not all that matter most to us.”  Following some of Nozick’s own suggestions, Finnis points out three things that matter to us deeply and are part of the positive content of human flourishing but that are lost in the experience machine.  First, activity matters to us.  We want to do things or at least try to do things, and the experience machine cuts genuine activity out of experience and leaves us completely passive.  Though when plugged into the machine you might think you had raised a family, hit a home run, solved a math problem, or planted a tree, in fact you would have done nothing.  You would have failed to drink the whole cup of life.  As Finnis says about a life spent hooked up to the experience machine, it is as though “you never lived.”  Thus, reflection on the experience machine reveals that human activity is desirable for itself. 

Second, while the experience machine can provide appearances, it cannot provide the genuine contact with reality that we want.  Illusions, ignorance, and dreams do not suffice.  We want real species preservation in the biosphere rather than the illusion that all is well in the animal and plant kingdoms.  We want actual people honestly and freely to love us rather than an electronic brain massage that makes us feel loved by other people.  We want genuine understanding of the real world rather than the mere subjective conviction that we have the wisdom of Solomon.  As Finnis puts this point, to opt for the experience machine “would be to bury oneself in a tomb far deeper than Plato’s Cave.”  At least Plato’s prisoners had genuine conversation with one another about the shadows they beheld.

Third, Finnis says that plugging into the experience machine also costs people their very identity.  How so?  Certainly, a person’s generic identity as a certain type of thing—a human being—would endure.  We would say “The human being Bob Anderson previously was not in the experience machine, now is, and later is no longer.”  So also, strict or numerical identity would also be maintained.  Unlike the Star Trek teletransporter that only can produce duplicates of the original, the experience machine leaves in tact the original person that plugged in.  We can point to the same spatial and temporal ‘this’ before, during, and after the encounter with the experience machine.  Moreover, much of a person’s specific identity would survive as well.  Concrete memories, linguistic abilities, the Pythagorean theorem, a short-temper, the hankering for prime rib, the dream of living to a ripe old age, and more would all survive the experience machine.  So, if these personality traits were part of a person’s specific identity before, then a person would, it seems, still possess them afterwards.  What then is the personal identity that Finnis thinks is lost in the experience machine?  It is two more aspects of a person’s specific identity.  First and in agreement with Nozick, some personality traits would be lost in the machine and others would remain undeveloped.  If we were a dedicated, loving parent before, we would no longer remain so after an extended stint in the machine because we would have failed to make the repeated choices that maintain our character as that sort of parent.  Likewise, if we were not already this or that kind of person, the chance to develop into this or that kind would be lost so long as a person was in the machine.  In short, what is commonly called personal character would be at risk, for it is something that can only be constructed and maintained by genuine acts of the will.[6]  Second, Finnis maintains that the choices I make, besides making me a type of person, also construct the I that I am.  My choices create the particular narrative that make me married or in the Army, an owner or a debtor, committed to a friendship or inattentive and uncaring, morally good or bad, deserving of praise or punishment, and so forth.  Choices make people not only what’s but also who’s.  They do not just create a character for a person, but also a person’s own character.  Since choices would cease while a person was plugged into the experience machine, the creation of a particular personal character or a particular personal narrative would also cease while a person remained plugged into the experience machine.

II. The Cyborg Thought Experiment

Now, a second thought experiment.  Suppose that after Cyberdyne Systems Corp.—the maker of the experience machine—fails dismally because a discriminating public snubs its first product, the company reorganizes as Cyborgdyne Systems Corp. and next ventures into human cyborgs.  Its new product rectifies the shortcomings of the experience machine.  No more simulated or faux experiences.  Users of the new product will remain active in and in contact with the world.  All aspects of personal identity will also remain.  In fact, users might in some ways live more fully than ever before, and they might become more fully the people that they have always wanted to be.

Cyborgdyne’s new product is a cyborg body that will replace most of a person’s natural, organic body.  All of the cyborg body’s parts and functions are synthetic.  The cyborg body is a complex, sophisticated, high-tech, man-made product that can do all that an organic body can do and more.  You can retain a human appearance (even your own), the five senses, and the ability to move, eat, drink, and breathe in all the ways that you currently can.  You can have sensations, emotions, memories, imagination, hopes, dreams, thoughts, and choices just as you do now.  So also, your interior existence can be as seamless with your exterior existence as it is now.  The interface between body and psyche which now leads you to say, “I don’t have or possess a body; I am a body,” is preserved so that you will experience your cyborg body as your very self.  You too will be led to say, “I don’t have or possess a cyborg body; I am a cyborg.”  You will experience your cyborg body as your very self, but you will also know the sober truth that most of your body is a man-made machine and not really you at all.  In addition, your cyborg body will be readily and painlessly repairable after injury, mutilation, and disfigurement.  As well, it will be immune to hideous, crippling, and deadly diseases.  Finally, it will be able to escape the ravages of time and many horrors of old age. 

The details of how an organic body is swapped out for a cyborg body are unimportant.  Cyborgdyne takes care of the details.  Cyborgdyne knows cyborgs.  Perhaps a person’s brain plus anything else essential for personal identity and numerical identity are transplanted into a cyborg.  Perhaps, instead, the cyborg comes to the person rather than the person to the cyborg.  A colony of nanobots (molecular-sized robots), for example, might be injected, and they might cannibalize the body’s cellular components, replicate themselves, coordinate their activity, and organize into highly complex systems, all the while leaving the brain or brain-plus-whatever-else alone.  In either case, the crux of the brain-in-a-cyborg thought experiment is the preservation of all that is lost in the experience machine (which thus makes it immune to all of Nozick’s and Finnis’ criticisms) and the elimination of most all, and as much as possible, human biological life.  Certainly much of our biological life is not necessary for personal identity and numerical identity to remain in tact, and this thought experiment pushes that fact to its limit.  (Think, for example, about how personal identity and numerical identity survive mutilation, disfigurement, severed limbs, broken spinal cords, organ and bone marrow transplants, joint replacements, blood transfusions, cell replacement, cochlea implants, pacemakers, insulin pumps, and more.)  The crucial question is, of course: would you want to be a brain (or brain-plus-whatever-else) in a cyborg?

I suspect that our answer to this question will not be as immediate as the rejection of the offer to plug into the experience machine, especially as we contemplate the attractiveness of some of a cyborg body’s amenities.  Nonetheless, the answer for many of us would be in the end, “No, I don’t want to be a cyborg even with all its amenities.”  Moreover, that “no” need not be a mere expression of stubborn resistance to change, sentimentality for the natural and organic, or nostalgia for our historical mode of existence.  Nor need the rejection of cyborg existence merely express a mild preference between minimally different alternatives.  Rather, from the rejection of the cyborg option we can recognize that something matters to us in addition to personality traits, character, self-constitution, and numerical identity.  We can recognize that human biological life is also a great good which matters to us 

But why does our biological life matter to us?  In recognizing the goodness of human biological life we have drilled down almost as far as we can go, but we have not yet hit bedrock.  We can still ask what is at the bottom of biological life’s importance to us.  Perhaps one reason for its importance is that, if something is going to exist physically, then it has to exist in some way or other, and we recognize that existing as a living organism is one desirable way of physically instantiating the good of existence.  After all, organic life is a beautiful thing and an engineering marvel.  Perhaps a second reason is that our biological life ties each of us to the whole family of man (past and present) and puts us in communion with the living world.  Each of us shows up on this planet with something else here that is and has been like us.  That we are not alone in this world but rather born into the community of humankind and the living is also something we value.  Perhaps a third reason is that biological life is just one of the brute facts about us that also constitutes who we are.  Like other brute facts—living on planet Earth, close but not too close to a helpful star, male or female, born in the 20th century, and so forth—they need not have been, but since they are and since they construct who we are, they are great gifts the universe has given us.

While many of us would reject the opportunity to be a brain in a cyborg, not all of us might.  This fact points to a difference between the experience-machine thought experiment and the brain-in-a-cyborg thought experiment.  The former requires that every person should reject the option of plugging into the experience machine.  In contrast, the brain-in-a-cyborg thought experiment does not require unanimous rejection of the cyborg option to show its point.  Perhaps existence as a cyborg is also good and choiceworthy,[7] but so long as some of us can reasonably say “we would not want to be cyborgs” then the experiment has done its work.  After all, no basic human good—not health, knowledge, beauty, friendship, sport, or any of the rest—is desired and pursued by every single person.  One can always find someone somewhere who does not like kids, is careless of health, finds that beauty leaves her flat, turns a cold shoulder to physical exertion in sport, or is uninterested in whether God exists and whether we owe him anything, if he does.  Goods are not basic because every single person is equally attracted to each one of them.  Instead, goods are basic because at least some people do find them to be ultimate sources of human fulfillment, and no good reasons exist to deny that those goods can function in this way.

III. Four Objections

First, a person might object that since at least brain life remains in the brain-in-a-cyborg thought experiment, the thought experiment does not show that the whole of human biological life is a fundamental good.  True enough.  The experiment does not swap out brain life for something else.  But brain life (or brain life plus) is retained to maintain personal identity and numerical identity, and the value of those identities has been shown, or can be shown, by reflection on what is lost in Nozick’s experience machine, teletransportation, and other thought experiments which filter out aspects of personal identity and numerical identity.  So, the value of brain life (or brain life plus whatever else is needed to preserve personal identity and numerical identity) has been, or can easily be, also established.

A person might object in a second way: the brain-in-a-cyborg thought experiment fails to consider several familiar problems in the philosophical literature on the relation of brains to personal identity.  For example, in a cerebrum transplant would personality identity come with the cerebrum, or stay with the cerebrum-less brain, or both, or neither?  Would splitting a brain with identical hemispheres and then transplanting each hemisphere into a different body result in two new people, or one old and one new person, or one old person in two new bodies?  How we answer these questions might impact what we should say about a brain in cyborg, so says the objector.  But, I do not see how.  While undoubtedly puzzles about personal identity exist, my argument does not require a solution to those puzzles.  So long as the brain in a cyborg preserves the conditions of personal identity and numerical identity together with a divorce from most of our generic identity as living animals, then the thought experiment does its work.  Whether all of the brain, part of the brain, or the brain plus other bodily parts and systems is required for personal identity and numerical identity can be left unresolved.

A person might object in yet a third way: though the brain-in-a-cyborg thought experiment does seem to show something, it is not clear that it shows what it is supposed to, namely, that human biological life is a fundamental good.  A person might object that since nobody is satisfied just being alive, human biological life is not an ultimate good.  No one would choose to exist as a frozen, non-developing embryo, or asleep in a coma, or in a persistent vegetative state, or behind the mental eclipse that results from advanced stages of Pick’s and Alzheimer’s disease.  So, biological life is not valuable in itself.  While, no doubt, human life adequately impoverished is not attractive, the problem with this objection is that it demands more of fundamental goods than they can deliver.  Its excessive demands result from the conflation of valuable for itself with valuable by itself.  I doubt anything in this world is desirable by itself.  No good by itself is so good that it can absorb completely the attention of minds like ours and the affection of hearts like ours.  Just the opposite is the case.  People always want an ensemble of goods, and the removal of even one can leave the rest disappointing.  The mind of Stephen Hawking and all the rest that comes from that with the unhealthy body of Stephen Hawking is not desirable.  Health, knowledge, and beauty in isolation on a deserted island disappoint.  The Shakers’ life of God, family, community, and craftsmanship coupled with profound ignorance, or psychological illness, or a guilty conscience come up short.  But that the pursuit of any fundamental good by itself is found to be deficient says nothing about the pursuit of it for itself.  Something is choiceworthy for itself because it is sought for the goodness it brings us, as opposed to its functioning as the means to yet something else that may or may not fulfill us. 

Finally, a person might try one last time: instead of proving that human biological life is a fundamental good, one might object, the brain-in-a-cyborg thought experiment only shows that such life has derivative goodness.  It is neutral, and the only goodness it has is a product of the goods made possible because a person is alive, such as knowledge, love, and the enjoyment of the beautiful.  According to this objection, it is all the extras that make human life good, not the life itself.   This objection, however, fails to pay attention to the illustrative force of the thought experiment.  If the extras in life are what make human biological life good, then the extras in life would also make existence as a cyborg good.  Yet many of us would not want to be cyborgs.  We want to be the living animals that we are.  So, human biological life is desirable for itself.    That life’s goodness is not dependent on the extras is also evident from reflection on the enormous satisfaction derived when life is achieved but the extras are still an open question.  When parents bring forth new life into this world, they are tremendously pleased even though the child may not live out the day.  After doctors have patched together the violent inner-city gang member who has been stabbed or shot, they can be quite satisfied at that moment even though the gang member later may revert to former ways and die in the next fight.  If in 1889 a local villager pushed a young, unsuspecting Joseph Stalin away from a runaway horse-drawn cart in his mountain-side Georgian village, the life saved was a life worth saving regardless of what the young Joseph Stalin was ultimately to become.  In each case, people can honestly say: “So far, so good.  We have served the good of life.”

IV. A Few Moral Considerations

The recognition that human biological life is fundamental human good rather than an instrumental good (like money or dental work) or a secondary good (like pleasure and enjoyment) or a derivative good (like honor and fame) is an important truth, but that truth does not, of course, by itself establish what, if anything, is the appropriate response by us to its reality.  In fact, people have strenuous moral obligations with regard to human life precisely because it is a fundamental good, and these obligations follow the general pattern of our obligations to other basic goods.  The short answer to the question “what are our obligations to human life?” is: To promote the good of human life and to respect that good by not intentionally harming it.  As for promoting human life, the obligation is indeterminate with respect to when, how often, and to what extent people are required to promote human life.  As for respecting human life, the obligation not to harm is indefeasible for all people and in all circumstances.  Here are a few brief considerations which make more plausible the claim that our obligations to human life are as stated.

Consider this alternative to the obligation to promote human life sometimes: promote the good of life always.  That we are obligated always to promote human life might seem to be plausible because the good of life in itself and in its well-being (health) is presupposed in the pursuit of all other goods.  We cannot pursue anything when we are dead, and we cannot pursue many goods when we are ill or injured.  But, even though life is a necessary condition for human pursuits, it is not the only good that human beings want.  A world in which every inhabitant is uninjured, healthy, and secure in the possession of life is not a happy world, if its inhabitants are merely uninjured, healthy, and alive.  The answer to the question “what are they doing now that they uninjured, healthy, and alive?” will decide whether or not they are happy.  Because other things matter to us and matter deeply to us, we often can reasonably risk life and neglect health when we are in pursuit of other goods besides life.  Thus, the obligation to promote human life is limited.

Next, consider three alternatives to the obligation never to harm human life intentionally, and consider first the supposed necessity involved in moral dilemmas.  Cannot people sometimes be in difficult circumstances such that, no matter what they do, they must harm human life?  For example, when the evil tyrant presents us with only two alternatives “you kill persons P, R, and Q or your loved ones will be killed,” then are we not stuck?  Either way we must do harm, no?  Moreover, if ought implies can and if sometimes we must intentionally do evil, then sometimes doing evil must be morally permissible.  In fact, though, all moral dilemmas are only apparent.  For, whatever the circumstances, the option of doing nothing at all is always among a person’s options, and when a person does nothing, the person does not harm anyone.  No doubt, in many circumstances the world or other people will do harm while a person stands on the sidelines doing nothing.  Similarly, no doubt, the opportunity for doing the good of preventing the world or other people from doing harm will be lost while a person stands on the sidelines doing nothing.  Nonetheless, if a person decides to do nothing, that person does no harm, and the refusal to do harm by doing nothing provides an escape from the bind which putative moral dilemmas appear to cause.

Second, we might think that there is hierarchy among fundamental goods such that intentionally harming a lower good is justified when it is done for the sake of a higher good.  If such a hierarchy exists, what good is highest?  Human life?  But if human life is highest, then we will not find in the appeal to a hierarchy of goods a justification of intentional harm to human life.  For in that case, lower goods can be attacked for its sake, but it cannot be attacked for their sake. 

How about autonomy instead?   Certainly, autonomy is prized by all, and many people view it as the preeminent and overarching good.  Accordingly, if a person wants to die, then the person is permitted to bring about her death because bringing it about is an expression of autonomy.  But if autonomy is the highest good, then ending another person’s life even when the person wants to live should also be permissible because ending the person’s life can be the expression of somebody else’s autonomy.  Most people, however, find this conclusion morally unacceptable.  The deep problem with autonomy as the highest good is that autonomy by itself cannot explain why we should take other people’s autonomy more seriously than our own when their wishes conflict with ours.  After all, they are no more and no less willing agents than we are.  If their wishes matter, then so do our wishes.  So, their desire for X can be countered by our desire for their not having X, and thus autonomy can not guide us in what we should do.  One might try again to defend autonomy by adding something else like a principle of consistency.  Accordingly, we should respect other people’s autonomy by not overriding their wishes so that in consistency they too will be obligated to respect our autonomy by not overriding our wishes.  Consistency, however, is a two-edged sword.  Instead of the non-compete agreement and détente of wills that results from mutual non-violations of autonomy, we could just as well opt for competition and conflict among wills and agree that to the victor go the spoils.  Thus, we are allowed to attempt to violate other people’s autonomy when doing so suits us, and in consistency other people are allowed to attempt to violate our autonomy when doing so suits them.  Since which version of consistency we embrace is arbitrary, so also is a morality founded on the combination of autonomy and consistency as the highest good.

The previous failure to identify the highest good indicates the difficulty in maintaining a hierarchy of fundamental goods.  Indeed, every candidate for the highest good can be defeated by careful inspection of the good and its functioning in the lives of real people.  Because a hierarchy of fundamental goods is ultimately indefensible, reference to such a hierarchy will not justify the intentional harm of human life.

Finally, we might think that the losses caused by the intentional harm of human life can be balanced against the gains brought about by the intentional harm.  Since the gains might sometimes outweigh the losses, we are sometimes justified in harming human life intentionally.  This calculation of loses and gains is the utilitarian’s creed.  However, no one has ever produced a plausible utilitarian calculation of anything.  Invariably, utilitarian calculations are never calculations of something objective.  Instead, they rely on base appeals to preexisting biases or feelings.  For example, the utilitarian might ask us to suppose that the life of a multi-murderer is worth 80% of the life of an innocent person, that a multi-murderer unless executed will kill seven more people, and thus that the execution of a multi-murderer brings about more good than bad.  Or, again, we might be asked to contemplate the merits of abortion when the female has been raped…and is a young girl…and her own uncle was the rapist…and the baby suffers terrible birth defects…and so forth.  Since talk in ethics of balancing pros and cons or weighing goods and evils is ultimately an empty metaphor, we cannot justify intentional harm to human life by appeal to concepts like balancing or weighing.


Admittedly, the last section is an extremely brief and general account of our moral requirements with respect to human life.  For present purposes, the crucial point is that the goodness of human life is not an idle curiosity.  Rather, it makes a difference morally.  Showing what difference it makes, however, requires the elaboration of moral theory.

Just as the cyborg thought experiment can lead us to recognize the goodness of human life, so also recognizing the goodness of human life can also enable us to make sense of human experience.  Why, for example, are even post-menopausal women sometimes reluctant to remove a cancerous uterus or cancerous ovaries?  Certainly, fear of medical complications is one reason.  But the main reason in many instances seems to be sorrow over the prospect that bodily parts intimate to their reality as women and child-bearers will be lost.  Again, why do some war veterans refuse to remove a functionless, unfeeling arm damaged from war injuries?  Certainly, hopes of restoration and aversion to disfigurement are some reasons.  But another reason seems to be an unwillingness to sacrifice the good of bodily integrity.  Finally, why are some people reluctant to and why do other people refuse to replace a dying heart with a baboon’s heart or a mechanical heart?  Certainly, there are many reasons.  But included among the reasons also seems to be a desire to remain fully what they are and always have been: a living human organism.     



Saint Anselm College

Manchester, New Hampshire 

About the Author

[1] (Oxford: Oxford University Press, 1987), pp. 307-309.

[2] (New York: Doubleday, 2008), chap.3.

[3] (Cambridge: Cambridge University Press, 2008), chap.1.

[4] Anarchy, State, and Utopia, (New York: Basic Books, 1974), pp. 42-45.

[5] (Washington, D.C.: Georgetown University Press, 1983), pp. 37-42.

[6] For more on the significance of acts of will for moral agents, see Christopher Tollefsen, “Experience Machines, Dreams, and What Matters,” Journal of Value Inquiry 37 (2003) 153-164.

[7] Although the cyborg option might be good and choiceworthy, exercising that option by swapping an organic body for a synthetic body might still run afoul of moral norms prohibiting the intentional destruction of one good for the sake of the realization of another good.