Limits of Intelligence
Does intelligence have limits? What might these be? Where do we humans stand on the intelligence scale? I will discuss these questions by reference to a Star Trek episode and a well-known philosophical contention involving bats. Don’t expect anything too definitive; these questions are very difficult (we may not have the intelligence to answer them). Still, some faint light can perhaps be cast, or possibilities opened up. At least the ride should be enjoyable. The Star Trek episode (“Errand of Mercy”) concerns a species of beings called “Organians”: as we learn towards the episode’s end, they consist of nothing but “thought and energy”, as Spock puts it (they give off a very bright light in their true undisguised form). They have evolved into this form following a corporeal existence many hundreds of thousands of years ago. They are vastly superior to us, morally and intellectually, and indeed to all known species. Spock puts it by saying that as we are to the amoeba, so they are to us: if we are a billion times more intelligent than an amoeba, then they are a billion times more intelligent than we are. They prove this by doing things that are beyond our comprehension, like disarming a whole Starfleet by thought alone (phasers disappear from hands, starships find themselves devoid of weapons). They are afraid of nothing and find us perfectly disgusting in our primitiveness and lack of moral enlightenment (ditto the Klingons). The Organians are one hell of a smart bunch, no question. Even Spock bows to their superior brain power (except they have no physical brain). To my mind, this raises the thorny question of whether it is possible to be a billion times cleverer than humans—to outstrip us as we outstrip the amoeba. Is this just science-fiction fantasy or strict nomological possibility (or even metaphysical possibility)? Is it just playing with words or is it something conceptually serious? What if I told you that there is another species, the super-Organians, that makes the Organians look like amoebas? And then another species that similarly outdoes the super-Organians (they can turn empty space into a whole galaxy just by…well, we are too dumb to understand how). Doesn’t this start to sound just a tad farfetched? And how could giving off a blindingly bright light make all this possible? What has light got to do with intelligence? But then, intelligence doesn’t belong on a scale that can be indefinitely extended—it has limits. We might want to say that Organians are as smart as it gets—it don’t get no smarter. They have reached the intelligence limit (compare the speed of light). Because intelligence has a limit, a point at which it cannot be increased. Before I explore this possibility further, I will set out the second type of argument for limited intelligence, observing only that the things the Organians are alleged to do seem literally impossible, in clear violation of physical law, godlike.
Materials for the second argument can be found in the work of Thomas Nagel, though I will refrain from attributing it to him—this argument was suggested to me by reading him. Let’s distinguish two kinds of fact: those that can be known only by possessing a particular point of view, and those that presuppose no particular point of view. Call the first class of facts subjective and the second class objective. Then we can say that facts about consciousness are subjective in this sense and facts about the physical world are objective. Accordingly, our knowledge of facts about consciousness is more limited than our knowledge of facts about the physical world (at least so far as the present argument is concerned). We can’t know what it’s like consciously to be a bat but we can know all about a bat’s brain, for example. Put in terms of intelligence, our intelligence is more limited in the one area than the other: we are more intelligent about the physical world than we are about the mental world, because we can in principle know more about the former than the latter. Even the Organians might have trouble with knowledge of the minds of inferior beings, since they cannot put themselves in their place (they do seem baffled by human psychology). The point is that, according to this way of thinking, intelligence will have limits imposed by the mechanisms and methods of knowing with which we are familiar. We can only grasp the nature of other minds by being mentally similar to them, but we can grasp the nature of physical reality without ourselves being similar to this reality (we know what an elephant is, say, though we are not physically similar to elephants). From this perspective, we have a clear argument for cognitive limits built into the knowing process; as I would put it, we are cognitively closed to bat experience, because subjective facts can only be known via similarity to the subjective properties of the knower. This similarity constraint applies to knowledge of consciousness but not to knowledge of physical body. Of course, we could overcome the similarity constraint by simply giving the would-be knower the very experiences he is endeavoring to grasp (e.g., echolocation experiences); but the point is that intelligence alone will not fill the gap—no amount of clever thinking is going to enable you to know what it’s like to be a bat. That, at any rate, is the argument. The Organians look like an untenable exaggeration of the fact of differences of intelligence, and the subjectivity argument appears to explain how at least one kind of cognitive limit can arise. Intelligence is not free to develop ad libitum.
But that argument itself has its limits. Are we to suppose that no objective knowledge is out of bounds—that there is no limit to how objectively intelligent you can be? Could there be objective Organians even if there can’t be subjective Organians? They can’t grasp alien minds but they can grasp anything in physical reality; and it makes sense to suppose that they are vastly more intelligent than us. Can we really be as stupid as Spock makes us out to be (including himself)? Also, the subjectivity argument runs into difficulty when generalized: does it establish clear limits in all cases? Consider moral knowledge: can you know what morality is (really is) and not yourself be a moral agent? This kind of knowledge seems to require a basis in self-knowledge—how can you know what is right and wrong and not apply those concepts to yourself? If you are not a moral being, you can’t know what it is like to be one. Animals don’t know what human morality is all about while lacking morality themselves, and I doubt that Klingons get it either (in fact, they have their own morality—they recognize moral imperatives of a martial type). This is not a matter of subjective states of consciousness but of moral values: you have to have them in order to know what they are. And what about certain general sorts of physical knowledge—can you know what space is and not yourself be in space? Can you know what shape is and have no shape—or mass or articulated structure? None of this is clear, but a case could be made this this type of knowledge is also constrained by the physical nature of the knower (especially his brain)? We don’t here have a clear criterion to judge whether a certain item of knowledge is available to the would-be knower or not. The situation is messier than we thought. Could you know about arithmetic but not be subject to it? Could you know about aesthetic properties but not have them yourself?
Where are we? We are trying to determine whether intelligence has limits, and if so why. The Organians sound implausible, and the subjectivity argument doesn’t settle the question generally (it was never meant to); so, what is the right thing to say? I want to say the following: reality is limited and there is no sense in the idea of an intelligence that goes beyond reality—therefore intelligence is limited (necessarily so). Consider a simple game like checkers: you can only get so good at it. There is no scope for vast differences of checkers intelligence; Organians are no better at checkers than humans are (let alone Vulcans). No one is ever going to get massively more intelligent at checkers than you or I. But reality is essentially like checkers: once you know the rules there is nowhere else to go. Intelligence is as good as it is ever going to be once the truth has been grasped. No doubt we are far from this state, but the point of principle remains: you can’t just keep on getting more intelligent once reality has been exhausted—and it must be exhaustible. Or, if you don’t like that kind of sweeping claim, certain sections of reality are such that intelligence will reach its limit with respect to those sections once they have been mapped out and understood. Reality is not unlimited, so intelligence has limits—the limits of reality (this includes technological products). Intelligence is not infinitely extensible; it is not true that for every level of intelligence there is a higher level. No one could be more intelligent (more omniscient) than God! Take logic: it is inconceivable that the Organians are better at logic than super-logical chief science officer Spock (he learned Godel’s theorem at his mother’s knee, if not before). Why? Because there is only so much logic to know and Spock knows it. The Organians are not somehow better at logic than human (or Vulcan) logicians; it isn’t as if they have an enormously superior grasp of modus ponens or conjunction elimination. I doubt they are much better at arithmetic or morality or Shakespeare interpretation or the history of the Second World War or chess or cookery or humor or bottle washing. There just isn’t an unlimited amount to know about these areas; there is no room for gigantic differences of intelligence. What would it even meanto say that Organians are a billion times better at Shakespeare interpretation than we are? I think it could be plausibly argued that human beings are close to the “end of intelligence” (some of them anyway), as they are not far from the end of science (how much is there left to know in biology?). Once the big discoveries have been made there is not much further you can go. Human intelligence may have reached a plateau and not much improvement can be expected, because we have already got so much right—in particular, logical reasoning. Spock is depicted as perfectly logical, and the idea is not absurd—you don’t get more intelligent at logic than Spock. Rationality (which is what Spock really means by “logic”) has been pretty much figured out (like elementary arithmetic or dish washing), so we cannot look forward to massive advances in it as time goes by; it will look much the same in ten thousand years as it does now. The basic principles are well established (the same goes for morality). We are biologically no more intelligent than Plato and Aristotle, and the same will hold for future thinkers. We will never be stunned by the intelligence of aliens—though the extent of their knowledge may surprise us.
There may be endogenous limits on our problem-solving power; no doubt there are. It isn’t just that reality itself has limits—a restricted budget of problems to be solved. So, human intelligence cannot be expected to grow and increase indefinitely: it will run out of things to be intelligent about, and also run up against its own intrinsic limitations. The same is presumably true of any intelligence in the universe. I would speculate that we are about nine tenths of the way there already, because so much has already been learned—about logic, morality, physics, astronomy, chemistry, biology, Shakespeare, philosophy, mathematics.[1] We are actually pretty damn intelligent, nothing like an amoeba. We could learn a lot from the Organians, no doubt, but not feel like complete dimwits in their presence; we could hold our head up intelligence-wise. This is simply because intelligence is not a quantity that can be increased ad infinitum. It has an upper limit and the signs are that we are not far from reaching it. I can see other species catching up with us in the fullness of time, but not our own species being massively surpassed by an alien intelligence (somewhat, yes, but not colossally).[2]
[1] For some reason this position is found incredible by many—science is far from at an end! But there is every reason to suppose that the scientific revolution, only a few centuries old, will one day wind down, and is even now winding down. I have discussed this elsewhere, as have others, and won’t defend it now.
[2] If our universe were smaller and simpler, easier to figure out from our vantagepoint, this position would be uncontroversial. As time goes by, it will become increasingly evident that we have figured out as much as we are going to figure out, and the idea of a superior intelligence will seem less and less compelling. I doubt that the Organians take seriously the idea of an intelligence superior to their own, and rightly so, because they know that they have it all under control. They know they know (hence their complacent smiles). They know their intelligence has it covered. No one can look down on them.
