The highest species concept may be that of a terrestrial rational being; however, we shall not be able to name its character because we have no knowledge of non-terrestrial rational beings that would enable us to indicate their characteristic property and so to characterize this terrestrial being among rational beings in general. It seems, therefore, that the problem of indicating the character of the human species is absolutely insoluble, because the solution would have to be made through experience by means of the comparison of two species of rational being, but experience does not offer us this. (Kant: Anthropology from a Pragmatic Point of View, 225)
Are there alien philosophers orbiting some faraway star, opining in bursts of symbolically articulated smells, or parsing distinctions-without-differences via the clasp of neural genitalia? What would an alien philosophy look like? Do we have any reason to think we might find some of them recognizable? Do the Greys have their own version of Plato? Is there a little green Nietzsche describing little green armies of little green metaphors?
I: The Story Thus Far
A couple years back, I published a piece in Scientia Salon, “Back to Square One: Toward a Post-intentional Future,” that challenged the intentional realist to warrant their theoretical interpretations of the human. What is the nature of the data that drives their intentional accounts? What kind of metacognitive capacity can they bring to bear?
I asked these questions precisely because they cannot be answered. The intentionalist has next to no clue as to the nature, let alone the provenance, of their data, and even less inkling as to the metacognitive resources at their disposal. They have theories, of course, but it is the proliferation of theories that is precisely the problem. Make no mistake: the failure of their project, their consistent inability to formulate their explananda, let alone provide any decisive explanations, is the primary reason why cognitive science devolves so quickly into philosophy.
But if chronic theoretical underdetermination is the embarrassment of intentionalism, then theoretical silence has to be the embarrassment of eliminativism. If meaning realism offers too much in the way of theory—endless, interminable speculation—then meaning skepticism offers too little. Absent plausible alternatives, intentionalists naturally assume intrinsic intentionality is the only game in town. As a result, eliminativists who use intentional idioms are regularly accused of incoherence, of relying upon the very intentionality they’re claiming to eliminate. Of course eliminativists will be quick to point out the question-begging nature of this criticism: They need not posit an alternate theory of their own to dispute intentional theories of the human. But they find themselves in a dialectical quandary, nonetheless. In the absence of any real theory of meaning, they have no substantive way of actually contributing to the domain of the meaningful. And this is the real charge against the eliminativist, the complaint that any account of the human that cannot explain the experience of being human is barely worth the name.  Something has to explain intentional idioms and phenomena, their apparent power and peculiarity; If not intrinsic or original intentionality, then what?
My own project, however, pursues a very different brand of eliminativism. I started my philosophical career as an avowed intentionalist, a one-time Heideggerean and Wittgensteinian. For decades I genuinely thought philosophy had somehow stumbled into ‘Square Two.’ No matter what doubts I entertained regarding this or that intentional account, I was nevertheless certain that some intentional account had to be right. I was invested, and even though the ruthless elegance of eliminativism made me anxious, I took comfort in the standard shibboleths and rationalizations. Scientism! Positivism! All theoretical cognition presupposes lived life! Quality before quantity! Intentional domains require intentional yardsticks!
Then, in the course of writing a dissertation on fundamental ontology, I stumbled across a new, privative way of understanding the purported plenum of the first-person, a way of interpreting intentional idioms and phenomena that required no original meaning, no spooky functions or enigmatic emergences—nor any intentional stances for that matter. Blind Brain Theory begins with the assumption that theoretically motivated reflection upon experience co-opts neurobiological resources adapted to far different kinds of problems. As a co-option, we have no reason to assume that ‘experience’ (whatever it amounts to) yields what philosophical reflection requires to determine the nature of experience. Since the systems are adapted to discharge far different tasks, reflection has no means of determining scarcity and so generally presumes sufficiency. It cannot source the efficacy of rules so rules become the source. It cannot source temporal awareness so the now becomes the standing now. It cannot source decisions so decisions (the result of astronomically complicated winner-take-all processes) become ‘choices.’ The list goes on. From a small set of empirically modest claims, Blind Brain Theory provides what I think is the first comprehensive, systematic way to both eliminate and explain intentionality.
In other words, my reasons for becoming an eliminativist were abductive to begin with. I abandoned intentionalism, not because of its perpetual theoretical disarray (though this had always concerned me), but because I became convinced that eliminativism could actually do a better job explaining the domain of meaning. Where old school, ‘dogmatic eliminativists’ argue that meaning must be natural somehow, my own ‘critical eliminativism’ shows how. I remain horrified by this how, but then I also feel like a fool for ever thinking the issue would end any other way. If one takes mediocrity seriously, then we should expect that science will explode, rather than canonize our prescientific conceits, no matter how near or dear.
But how to show others? What could be more familiar, more entrenched than the intentional philosophical tradition? And what could be more disparate than eliminativism? To quote Dewey from Experience and Nature, “The greater the gap, the disparity, between what has become a familiar possession and the traits presented in new subject-matter, the greater is the burden imposed upon reflection” (Experience and Nature, ix). Since the use of exotic subject matters to shed light on familiar problems is as powerful a tool for philosophy as for my chosen profession, speculative fiction, I propose to consider the question of alien philosophy, or ‘xenophilosophy,’ as a way to ease the burden. What I want to show is how, reasoning from robust biological assumptions, one can plausibly claim that aliens—call them ‘Thespians’—would also suffer their own versions of our own (hitherto intractable) ‘problem of meaning.’ The degree to which this story is plausible, I will contend, is the degree to which critical eliminativism deserves serious consideration. It’s the parsimony of eliminativism that makes it so attractive. If one could combine this parsimony with a comprehensive explanation of intentionality, then eliminativism would very quickly cease to be a fringe opinion.
II: Aliens and Philosophy
Of course, the plausibility of humanoid aliens possessing any kind of philosophy requires the plausibility of humanoid aliens. In popular media, aliens are almost always exotic versions of ourselves, possessing their own exotic versions of the capacities and institutions we happen to have. This is no accident. Science fiction is always about the here and now—about recontextualizations of what we know. As a result, the aliens you tend to meet tend to seem suspiciously humanoid, psychologically if not physically. Spock always has some ‘mind’ with which to ‘meld’. To ask the question of alien philosophy, one might complain, is to buy into this conceit, which although flattering, is almost certainly not true.
And yet the environmental filtration of mutations on earth has produced innumerable examples of convergent evolution, different species evolving similar morphologies and functions, the same solutions to the same problems, using entirely different DNA. As you might imagine, however, the notion of interstellar convergence is a controversial one.  Supposing the existence of extraterrestrial intelligence is one thing—cognition is almost certainly integral to complex life elsewhere in the universe—but we know nothing about the kinds of possible biological intelligences nature permits. Short of actual contact with intelligent aliens, we have no way of gauging how far we can extrapolate from our case.  All too often, ignorance of alternatives dupes us into making ‘only game in town assumptions,’ so confusing mere possibility with necessity. But this debate need not worry us here. Perhaps the cluster of characteristics we identify with ‘humanoid’ expresses a high-probability recipe for evolving intelligence—perhaps not. Either way, our existence proves that our particular recipe is on file, that aliens we might describe as ‘humanoid’ are entirely possible.
So we have our humanoid aliens, at least as far as we need them here. But the question of what alien philosophy looks like also presupposes we know what human philosophy looks like. In “Philosophy and the Scientific Image of Man,” Wilfred Sellars defines the aim of philosophy as comprehending “how things in the broadest possible sense of the term hang together in the broadest possible sense of the term” (1). Philosophy famously attempts to comprehend the ‘big picture.’ The problem with this definition is that it overlooks the relationship between philosophy and ignorance, and so fails to distinguish philosophical inquiry from scientific or religious inquiry. Philosophy is invested in a specific kind of ‘big picture,’ one that acknowledges the theoretical/speculative nature of its claims, while remaining beyond the pale of scientific arbitration. Philosophy is better defined, then, as the attempt to comprehend how things in general hang together in general absent conclusive information.
All too often philosophy is understood in positive terms, either as an archive of theoretical claims, or as a capacity to ‘see beyond’ or ‘peer into.’ On this definition, however, philosophy characterizes a certain relationship to the unknown, one where inquiry eschews supernatural authority, and yet lacks the methodological, technical, and institutional resources of science. Philosophy is the attempt to theoretically explain in the absence of decisive warrant, to argue general claims that cannot, for whatever reason, be presently arbitrated. This is why questions serve as the basic organizing principles of the institution, the shared boughs from which various approaches branch and twig in endless disputation. Philosophy is where we ponder the general questions we cannot decisively answer, grapple with ignorances we cannot readily overcome.
III: Evolution and Ecology
A: Thespian Nature
It might seem innocuous enough defining philosophy in privative terms as the attempt to cognize in conditions of information scarcity, but it turns out to be crucial to our ability to make guesses regarding potential alien analogues. This is because it transforms the question of alien philosophy into a question of alien ignorance. If we can guess at the kinds of ignorance a biological intelligence would suffer, then we can guess at the kinds of questions they would ask, as well as the kinds of answers that might occur to them. And this, as it turns out, is perhaps not so difficult as one might suppose.
The reason is evolution. Thanks to evolution, we know that alien cognition would be bounded cognition, that it would consist of ‘good enough’ capacities adapted to multifarious environmental, reproductive impediments. Taking this ecological view of cognition, it turns out, allows us to make a good number of educated guesses. (And recall, plausibility is all that we’re aiming for here).
So for instance, we can assume tight symmetries between the sensory information accessed, the behavioural resources developed, and the impediments overcome. If gamma rays made no difference to their survival, they would not perceive them. Gamma rays, for Thespians, would be unknown unknowns, at least pending the development of alien science. The same can be said for evolution, planetary physics—pretty much any instance of theoretical cognition you can adduce. Evolution assures that cognitive expenditures, the ability to intuit this or that, will always be bound in some manner to some set of ancestral environments. Evolution means that information that makes no reproductive difference makes no biological difference.
An ecological view, in other words, allows us to naturalistically motivate something we might have been tempted to assume outright: original naivete. The possession of sensory and cognitive apparatuses comparable to our own means Thespians will possess a humanoid neglect structure, a pattern of ignorances they cannot even begin to question, that is, pending the development of philosophy. The Thespians would not simply be ignorant of the microscopic and macroscopic constituents and machinations explaining their environments, they would be oblivious to them. Like our own ancestors, they wouldn’t even know they didn’t know.
Theoretical knowledge is a cultural achievement. Our Thespians would have to learn the big picture details underwriting their immediate environments, undergo their own revolutions and paradigm shifts as they accumulate data and refine interpretations. We can expect them to possess an implicit grasp of local physics, for instance, but no explicit, theoretical understanding of physics in general. So Thespians, it seems safe to say, would have their own version of natural philosophy, a history of attempts to answer big picture questions about the nature of Nature in the absence of decisive data.
Not only can we say their nascent, natural theories will be underdetermined, we can also say something about the kinds of problems Thespians will face, and so something of the shape of their natural philosophy. For instance, needing only the capacity to cognize movement within inertial frames, we can suppose that planetary physics would escape them. Quite simply, without direct information regarding the movement of the ground, the Thespians would have no sense of the ground changing position. They would assume that their sky was moving, not their world. Their cosmological musings, in other words, would begin supposing ‘default geocentrism,’ an assumption that would only require rationalization once others, pondering the movement of the skies, began posing alternatives.
One need only read On the Heavens to appreciate how the availability of information can constrain a theoretical debate. Given the imprecision of the observational information at his disposal, for instance, Aristotle’s stellar parallax argument becomes well-nigh devastating. If the earth revolves around the sun, then surely such a drastic change in position would impact our observations of the stars, the same way driving into a city via two different routes changes our view of downtown. But Aristotle, of course, had no decisive way of fathoming the preposterous distances involved—nor did anyone, until Galileo turned his Dutch Spyglass to the sky. 
Aristotle, in other words, was victimized not so much by poor reasoning as by various perspectival illusions following from a neglect structure we can presume our Thespians share. And this warrants further guesses. Consider Aristotle’s claim that the heavens and the earth comprise two distinct ontological orders. Of course purity and circles rule the celestial, and of course grit and lines rule the terrestrial—that is, given the evidence of the naked eye from the surface of the earth. The farther away something is, the less information observation yields, the fewer distinctions we’re capable of making, the more uniform and unitary it is bound to seem—which is to say, the less earthly. An inability to map intuitive physical assumptions onto the movements of the firmament, meanwhile, simply makes those movements appear all the more exceptional. In terms of the information available, it seems safe to suppose our Thespians would at least face the temptation of Aristotle’s long-lived ontological distinction.
I say ‘temptation,’ because certainly any number of caveats can be raised here. Heliocentrism, for instance, is far more obvious in our polar latitudes (where the earth’s rotation is as plain as the summer sun in the sky), so there are observational variables that could have drastically impacted the debate even in our own case. Who knows? If it weren’t for the consistent failure of ancient heliocentric models to make correct predictions (the models assumed circular orbits), things could have gone differently in our own history. The problem of where the earth resides in the whole might have been short-lived.
But it would have been a problem all the same, simply because the motionlessness of the earth and the relative proximity of the heavens would have been our (erroneous) default assumptions. Bound cognition suggests our Thespians would find themselves in much the same situation. Their world would feel motionless. Their heavens would seem to consist of simpler stuff following different laws. Any Thespian arguing heliocentrism would have to explain these observations away, argue how they could be moving while standing still, how the physics of the ground belongs to the physics of the sky.
We can say this because, thanks to an ecological view, we can make plausible empirical guesses as to the kinds of information and capacities Thespians would have available. Not only can we predict what would have remained unknown unknowns for them, we can also predict what might be called ‘unknown half-knowns.’ Where unknown unknowns refer to things we can’t even question, unknown half-knowns refer to theoretical errors we cannot perceive simply because the information required to do so remains—you guessed it—unknown unknown.
Think of Plato’s allegory of the cave. The chained prisoners confuse the shadows for everything because, unable to move their heads from side to side, they just don’t ‘know any different.’ This is something we understand so intuitively we scarce ever pause to ponder it: the absence of information or cognitive capacity has positive cognitive consequences. Absent certain difference making differences, the ground will be cognized as motionless rather than moving, and celestial objects will be cognized as simples rather than complex entities in their own right. The ground might as well be motionless and the sky might as well be simple as far as evolution is concerned. Once again, distinctions that make no reproductive difference make no biological difference. Our lack of radio telescope eyes is no genetic or environmental fluke: such information simply wasn’t relevant to our survival.
This means that a propensity to theorize ‘ground/sky dualism’ is built into our biology. This is quite an incredible claim, if you think about it, but each step in our path has been fairly conservative, given that mere plausibility is our aim. We should expect Thespian cognition to be bounded cognition. We should expect them to assume the ground motionless, and the constituents of the sky simple. We can suppose this because we can suppose them to be ignorant of their ignorances, just as we were (and remain). Cognizing the ontological continuity of heaven and earth requires the proper data for the proper interpretation. Given a roughly convergent sensory predicament, it seems safe to say that aliens would be prone as we were to mistake differences in signal with differences in being and so have to discover the universality of nature the same as we did.
But if we can assume our Thespians—or at least some of them—would be prone to misinterpret their environments the way we did, what about themselves? For centuries now humanity has been revising and sharpening its understanding of the cosmos, to the point of drafting plausible theories regarding the first second of creation, and yet we remain every bit as stumped regarding ourselves as Aristotle. Is it fair to say that our Thespians would suffer the same millennial myopia?
Would they have their own version of our interminable philosophy of the soul?
 The eliminativism at issue here is meaning eliminativism, and not, as Stich, Churchland, and many others have advocated, psychological eliminativism. But where meaning eliminativism clearly entails psychological eliminativism, it is not at all obvious the psychological eliminativism entails meaning eliminativism. This was why Stich, found himself so perplexed by the implications of reference (see his, Deconstructing the Mind, especially Chapter 1). To assume that folk psychology is a mistaken theory is to assume that folk psychology is representational, something that is true or false of the world. The critical eliminativism espoused here suffers no such difficulty, but at the added cost of needing to explain meaning in general, and not simply commonsense human psychology.
 See Kathryn Denning’s excellent, “Social Evolution in Cosmic Context,” http://www.nss.org/resources/library/spacepolicy/Cosmos_and_Culture_NASA_SP4802.pdf
 Nicolas Rescher, for instance, makes hash of the time-honoured assumption that aliens would possess a science comparable to our own by cataloguing the myriad contingencies of the human institution. See Finitude, 28, or Unknowability, “Problems of Alien Cognition,” 21-39.
 Stellar parallax, on this planet at least, was not measured until 1838.