Is C-3PO Alive?

by Will Swanson and Eric Schwitzgebel

Droids—especially R2-D2, C-3PO, and BB-8—propel the plot of the Star Wars movies. A chance encounter between R2-D2 and Luke Skywalker in “Episode IV: A New Hope” starts Luke on his fateful path to joining the rebel forces, becoming a Jedi, and meeting his father. More recently, BB-8 plays a similar role for Rey in “Episode VII: The Force Awakens”. But the droids are more than convenient plot devices. They are full-blooded characters, with their own quirks, goals, preferences, and vulnerabilities. The droids face the same existential threats as anyone else; and most of us still squirm in our theater seats on their behalf when danger looms.

Our response to the Star Wars droids relies on the tacit assumption that they are living lives -- lives that can be improved or worsened, sustained or lost. This raises the question: Is C-3PO alive? Or more precisely, if we someday built a robot like C-3PO, would it be alive?

In a way, it seems obvious that, yes, C-3PO is alive. Vaporizing him would be murder! One could have a funeral over his remains, reminiscing about all the good things he did in his lifetime.

But of course, the experts on life are biologists. And if you look at standard biology textbook descriptions of the characteristics of life (e.g., here), it looks like robots wouldn’t qualify. They don’t grow or reproduce, or share common descent with other living organisms. They don’t contain organic molecules like nucleic acid. They don’t have biological cells. They don’t seem to have arisen from a Darwinian evolutionary process. Few people (and probably fewer professional biologists) would say that a Roomba vacuum cleaner is alive, except in some kind of metaphorical sense; and in these respects, C-3PO is similar, despite being more complicated – just as we are similar to but more complicated than microscopic worms. The science covering C-3PO is not biology, but robotics.

Despite what looks like bad news for C-3PO from biology textbook definitions of life, on closer consideration we should reject the biology-textbook-list approach to robot cases. Our attitude toward these lists should probably be closer to the capacious attitude typical of astrobiologists (e.g., Benner 2010). If we’re considering what “life” is, really, in the broad, philosophical way that we do when considering the possibility of alien life, the standard lists start to look very Earth-bound and chauvinistic.

Common descent. Unless we wish to exclude the possibility of life originating independently on other planets, we should not treat common descent as a necessary condition for life.

Organic molecules. If we allow for life to arise independently on other planets, we should also be wary of expecting the resultant life to closely resemble biological life on Earth. We should not require the presence of organic molecules like nucleic acids.

Reproduction. While it is true that biological living things tend to reproduce when given the opportunity, reproduction is far from necessary for life. Consider the mule, the sterile worker ant, and the deliberately childless human. Nor should we require that life forms originate from reproductive processes. If life began without reproduction once, it can begin again, perhaps many times over!

Participation in Darwinian processes. Explanations invoking evolution by natural selection have revealed many of nature’s secrets. Nevertheless, evolution is not a locally defined property of living individuals. It refers to the processes that shape individuals over generations. It’s unclear why belonging to a group that has undergone Darwinian selection in the past should matter to whether an individual, considered now, is alive.

Growth. Depending on the sense of growth in question, robots may or may not grow. If growth means nothing more than change over time in accordance an internal protocol, then at least some robots, learning ones, are able to grow. If growth means simply getting radically bigger (or developing from a small seed or embryo into a large adult), then requiring growth risks excluding or marginalizing many organisms that are uncontroversially alive, such as bacteria that reproduce by fission.

Other list members -- self-maintenance (if a robot can charge its own battery...), having heterogeneous organized parts, and responding to stimuli -- pose no challenge to the idea that robots are alive.

What about metabolism? Perhaps this is an essential feature of life. Do robots do this?

Tweaking a suggestion from Peter Godfrey-Smith (2013), a first pass on a definition for metabolism is the cooperation of diverse parts within an organism (implicitly, a thing that meets other criteria for life) to use energy and other resources to maintain the structure of the organism. If “maintaining structure” amounts to maintaining operational readiness, then this definition provides no reason to deny metabolism to robots, especially robots that do things like auto-update, repel virus programs, and draw from external energy resources as needed. If “maintaining structure” refers specifically to the upkeep required to keep a physical body from degrading, then most simple robots would be excluded, but C-3PO would still qualify, if he can polish his head and order a replacement arm.

Even so, this second approach might define metabolism too narrowly. Defining metabolism in terms of maintenance in a narrow sense, after all, cannot accommodate the other ends to which organisms put energy in coordinated, non-accidental ways. Consider growth and development. The caterpillar’s metamorphosis hardly counts as maintenance of structure in any straightforward sense, yet we should count the energy transformations needed to effect that change as part of the caterpillar’s metabolism. More strikingly, living things often use energy to undermine their structure: think of cells undergoing programmed cell death or humans committing suicide.

We can accommodate these cases by broadening the definition of metabolism to encompass any coordinated use of energy within a living thing to achieve the ends of that living thing. On this broader definition, there is no reason to deny metabolism to robots.

With all of this in mind, we think it’s not unreasonable to stick with our gut intuition that C-3PO is alive. What is essential to being a living thing is not so much one’s biological history or composition by organic molecules, but rather the use of internal or environmental resources to accomplish the functional aims of the system.

How sophisticated does a system need to be to qualify as living, by these standards? Should we maybe say that even a Roomba is alive, after all? In a series of entertaining experiments, Kate Darling has shown that ordinary people are often quite reluctant to smash up cute robots. Despite Darling’s own expressed view that such robots aren’t alive, maybe part of what is holding people back is some of the same thing that holds some of us back from wanting to crush spiders -- a kind of emotional reverence for forms of life.

A darling robot:

Philosophers have grown used to functionalism about mind -- that is, they seem generally willing to accept or at least take seriously the possibility that consciousness might be realized in non-biological substrates. Nevertheless, functionalism about life is less readily accepted. Perhaps philosophical reflection about the possibility of robotic life can help us recognize that our concern over the lives and deaths of our favorite robot characters may be perfectly justified.

[C-3PO image source] [Pleo image source]