Martian Rabbit Superorganisms, Yeah!
Most philosophers of mind (but not all) believe that rabbits have conscious experiences -- that rabbits are not, as it were, mere machines all dark inside but rather that there's "something it's like" to be a rabbit, that they can have sensory experiences, that they can experience pain, that they have (in contemporary jargon) "phenomenology". After all, rabbits are not so different from us, biologically. Rabbits might lack language and higher forms of abstract and self-reflective cognition, but few philosophers think that such differences between us and them are sufficient to render rabbits nonconscious.
Most philosophers of mind (but not all) likewise believe that if we were visited by a highly intelligent naturally-evolved alien species -- let's call them "Martians" -- that alien species might possess a radically different biology from us and yet still have conscious experience. Outwardly, let's suppose, Martians look rather like humans; and also they behave rather like humans, despite their independent evolutionary origins. They visit us, learn English, and soon integrate into schools and corporations, maybe even marriages. They write philosophical treatises about consciousness and psychological treatises about their emotions and visual experiences. We will naturally, and it seems rightly, think of such Martians as genuinely conscious. Inside, though, they have not human-style neurons but rather complicated hydraulics or optical networks or the like. To think that such beings would necessarily be nonconscious zombies, simply because their biology is different from ours, seems weirdly chauvinistic in a vast universe in which complex systems, intelligently responsive to their environments, can and do presumably evolve myriad ways.
Okay, so how about Martian rabbits? Martian rabbits would be both biologically and behaviorally very different from you and me. But it seems hard to justify excluding them from the consciousness club, if we let in both Earthly rabbits and Martian schoolteachers. Right?
Ready for a weirder case? Martian Smartspiders, let's suppose, are just as intelligent and linguistically sophisticated as the Martian bipeds we love so well. In fact, we couldn't distinguish the two in a Turing Test. But the Smartspiders are morphologically very different from bipeds. Smartspiders have a central body that contains basic biological functions, but most of their cognitive processing is distributed among their 1000 legs (which evolved from jellyfish-like propulsion and manipulation tentacles). Information exchange among these thousand legs is fast, since in the Martian ecosystem peripheral nerves operate not by the slowish chemical-electrical processes we use but rather by shooting light through reflective capillaries (fiber optics), saving precious milliseconds of reaction time. Thus the 1000 distributed centers of cognitive processing can be as quickly and tightly informationally integrated as are different regions of our own brains -- and the ultimate output is just as smart and linguistic as ours. If there were such Turing-Test-passing Martian Smartspiders, it seems we ought to let them into the bounds of genuinely conscious organisms, if we're letting in the bipedal Martians and the Martian rabbits.
Suppose Martian Smartspiders evolve so that their legs become detachable, while still capable of movement and control by the organism as a whole. The detachment can work because the nerve signals are light-based: The Martian just needs to replace directly connective fibers with transducers that can propagate the light signal across the gap from the surface of the limb to the portion of the central body where that limb had previously been attached. One can see how detachable limbs might be advantageous in hunting and in reaching into narrow spaces. Detaching a leg should have negligible impact on cognition speed as long as there are suitable transducers on the surface of the leg and on the surface of the main body where it normally attaches, since the information will cross the gap at lightspeed. If we put the Martian Smartspider in a sensory deprivation room and disable its proprioceptive system, it might not even be able to tell if its legs are attached or not.
So here's the Smartspider. Its thousand limbs venture out, all under the constant distributed control of the Smartspider -- just as much control and integration as if they were attached. She's still a conscious organism, though spatially distributed, right?
Now imagine the Smartspider gets dumb. As dumb as a rabbit. Evolutionary pressures support a general specieswide reduction in intelligence. Now we have a Notsosmartspider. Is there any good reason to think it wouldn't be conscious if the rabbit is conscious?
Finally, let's take these thoughts home to Earth. The most sophisticated ant colonies (e.g., large leaf cutter colonies) are as intelligent and sophisticated in their behavior as rabbits. If we're going to reject biological chauvinism and continguism (prejudice against discontiguous entities) on behalf of the Martians, why not reject those prejudices on behalf of Earthly superorganisms too? Maybe the colony as a whole has a distinctive, unified stream of conscious experience, of roughly mammal-level intelligence, above and beyond the consciousness of the individual ants (if individual ants even do have individual consciousness).
There are potentially important differences between the Notsosmartspider and an ant colony. Individual ants might not be as tightly informationally integrated as are the pieces of the Notsosmartspider as I've imagined it, and the rules governing their interaction might be fairly simple, despite leading to sophisticated emergent behavior. But should we regard such differences as decisive? As a thought experiment, imagine those differences first in the brain of a single Martian biped.
And if ant colonies are conscious, might the United States be conscious too?
[Revised May 5]