London's Science Museum has an entire gallery—dubbed “Who Am I?”—dedicated to the latest advances in genetics and neuroscience. In early February the gallery welcomed Rex, the bionic man. Rex is short for “robotic exoskeleton;” he was constructed by the Shadow Robot Company, and featured in a documentary on British television: “How to Build a Bionic Man.” The project’s goal was to assemble the most advanced example of a bionic man, using contributions from laboratories throughout the world.
The principal narrator of the film, Bertolt Meyer, is a Swiss psychologist with an advanced prosthetic hand. The hand has functioning fingers enabling its user (or, perhaps better, its wearer) to grasp objects as a normal biological hand can. Electric sensors in the new hand pick up signals generated by muscle movements in the arm. Bionic hands are only a small part of what constitutes Rex.
Today’s advances in prosthetics and other artificial devices are accessible to us through websites like this one, where you can build a “bionic you” by selecting a part of the body you would like to replace or enhance. You can select either an exterior view (feet, ankles, knees, hips, arms, hands, eyes, and ears—the whole exoskeleton) or an interior view (heart, lungs, trachea, spleen, kidneys, pancreas, arteries, and blood). When you click on a body part, you can read about “cutting edge” developments on it.
The artificial implantable kidney, for example, isn’t available to the public yet, but would end a patient's need for dialysis and immune-suppressant medications. Several of Rex’s internal organs are still only at the prototype stage, but others are now usable. Mechanical hearts with an external power source beat inside recipients. Cochlear implants for ears are not uncommon, and, more recently, scientists have developed a microchip for the back of the eye that can bring some sight to the blind. As one writer in the Guardian put it with more than a little hyperbole: Bionic organs connect directly “to our own metabolism—in effect, they are not within us, they become us. They’re the ultimate in biomimicry.”
The bionic man can hear through cochlear ears, see with the aid of a bionic eye, has speech software (similar to Stephen Hawking’s) for verbal responses, and a rudimentary kind of artificial intelligence. Nearly all these developments come from advanced electrical engineering that connects to or mimics electrical signals from muscles and nerves.
Is the Bionic Man Human?
To speak of the bionic man’s being able to “hear,” “see,” and “talk” raises philosophical questions about whether the bionic man is truly performing “human” functions. It is, after all, not the ear that hears or the eye that sees; rather human beings hear and see, albeit with the aid of ears and eyes.
One noticeable absence, and understandably so, concerns the brain. Researchers note that the amazing complexity of the brain (it contains some 100 billion neurons) cannot yet be replicated. There is some hope that certain areas of the brain, especially those thought to be related to memory, might be replaced with “neural prosthetics.”
Extraordinary advances in prosthetics, and construction of some artificial organs, have revolutionized medical care for many people, although these devices are very expensive. One scientist at MIT who lost both his legs to frostbite when he was a teenager tells us that his new legs, ankles, and feet function far better than the ones he had lost. In fact, he can change his feet and ankles (he has several sets) to conform to different activities, such as climbing steep cliffs.
Another scientist has wondered aloud whether some people might wish to replace their present, normally functioning legs with new specially engineered ones that would help them perform tasks—or compete in athletic events—in an enhanced mode. Just as plastic surgery may be elected for purely cosmetic purposes, the great advances in exoskeleton prosthetics may encourage a similar kind of elective surgery. Meyer muses that these new inventions are taking us “beyond the limits of evolution” with the result that we may find our current “normal” bodies to be boring.
What are we to make of this new man-made man? Is he what one commentator called a “walking, talking, blood pumping vision of our medical future?” Some might think that Rex and his various organs blur the line between nature and artifice. How do we compare “the patchwork assembly of parts,” as Meyer himself called Rex, with a unified, living organism, in this case, a human being? Surely, Rex is one thing, but is the bionic man a unity in the same way that a human being is a unity? And does it make a difference?
Even if Rex’s parts could coordinate better in the future, is there a difference between his mechanical unity and the unity of a human body? Is a prosthetic arm or foot, for example, integrated by elaborate electrical circuitry with muscles and nerves, united to a human organism in the same way that a natural arm or foot is? Is the difference in unity one of degree or kind?
It’s hard to distinguish man from machine if one takes a materialist and reductionist view of human nature—in other words, if one sees nature as nothing more than an assemblage of material parts. Moreover, any difference between living and non-living becomes, at best, a matter of convention.
Mechanistic materialism has profound ethical consequences. If living things are simply complicated machines, why should we treat them differently from non-living things? Ethics is grounded by our view of what the world is really like. It is important, then, to think clearly about machines and organisms, for confusion about the basics leads to confusion about how to act. If living things are nothing but complex machines, the sum of their diverse parts, it becomes easy to see all of evolutionary history as only a mechanical, algorithmic process.
Why Machines Aren’t Humans, and Humans Are Always More Than Machines
To understand that living things have a unity very different from the unity of machines, and that a materialist mechanistic account of human nature and evolutionary history are inadequate at best, we need to consider questions in natural philosophy and metaphysics.
Professor Steven Baldner's work in the philosophy of nature is of considerable value here, and I have used some of his insights in what follows.
A comparison between machines and organic bodies is not so unusual. Organic bodies, unlike inorganic ones, have spatially distinguishable organs. Inorganic bodies can be divided only in the way that we can separate one quantitative part from another.
In a human being, for example, the heart is really separate from and in a certain spatial relationship to the lungs, just as in an engine diverse functioning parts are separate from each other. A machine is also like a living organism insofar as a machine performs functions as a whole that are greater than those of the parts. The machine, like the plant or animal, seems to be greater than the sum of its parts, and a machine can only perform its functions if its parts have the proper order.
At the same time, despite these likenesses, living organisms differ in an irreducible way from machines. The organs of living things are not machine parts. Organs are produced simultaneously with the whole organism and develop while the organism is growing; mechanical parts, on the other hand, are made separately from the whole machine and independently of the other parts. The various parts used to construct Rex were made in diverse places. Although their designs reflected their future uses in relation to the other parts, they still could perform their functions independently of Rex. The batteries, motors, springs, tubing, and the like that together form a machine can function separately from it.
But no organ can perform its function apart from a living organism. Transplant organs can be preserved with great care, but cannot function, apart from human bodies. The function of living organs is determined precisely by the organism as a whole, that is, from within, while the function of mechanical parts is always somewhat arbitrary, as new functions can be found for old parts. Both the machine’s order of parts, and its purpose in functioning, are imposed from without, by its craftsman or engineer.
Machines are always moved by something extrinsic to them, and this source of motion, whether a motor or agent or fuel, can be separated from the machine or replaced by some other source, even a source of a different kind. The mechanical heart has an external source of power; other artificial implants include a power source built into them.
A living being, in contrast, takes its nutrients from the environment but transforms these non-living materials into a living part of itself. This process is not storing some material, as fuel is stored in a gasoline tank, but is rather transforming the non-living into the living. This process involves converting simpler substances into more complex ones, such as fats and carbohydrates, but it makes non-living food part of the living organism that consumes and metabolizes it. When the machine or any of its parts draws electricity from an outside source (including from batteries implanted with the artificial organ), there is no transforming of the electricity into the very fabric of the machine.
Reproduction also distinguishes organisms from machines: It is not the reconfiguring of various elements to produce a new thing, like the replication of a machine. Reproduction is preceded by physical and chemical changes, but is itself a biological change; it has an autonomy and identity of its own.
When we make things, no matter how complex they are, we act as an agent cause, but we work with already existing things that have their own proper natures and characteristic behavior, and in many instances their own latent agency. We are agents of a special kind, possessing intelligence, which differentiates us from what inanimate and other animate beings possess.
Since we need materials to make anything, including a bionic man, we don’t have the kind of agency or power that God has. Divine creative agency doesn’t require any material at all to produce all that is; it exhibits an infinite power. Infinite power is not simply more power than the highest creature can exercise; it is a power of a radically different sort.
We may replace, repair, or enhance crucial parts of our bodies, but there must be a living human organism who already exists and on whom or in whom these medical-technological procedures occur for us to say that we are enhancing a human being. We are not an assemblage of diverse, replaceable parts, even though we are able to function with the help of highly complex man-made mechanisms. Living beings possess a unity, and a biological continuity, fundamentally different from the kind of unity (and the activities that flow from it) of the most sophisticated machine.
William E. Carroll is the Thomas Aquinas Fellow in Theology and Science at Blackfriars Hall and a member of the Faculty of Theology and Religion at the University of Oxford.
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