Philosopher Thomas Nagel famously argued in an article written in the 1970s that we can’t know what it’s like to be a bat. Given that bats are mammals, and fairly sophisticated ones at that, it seems clear that they have experiences. But considering that they navigate the world via echolocation, a sense we don’t have, it also seems clear that their experiences are radically different from ours. Of course, one might engage in all sorts of imaginative exercises in an effort to try to figure out what bat experiences are like – one might imagine oneself having webbing on one’s arms, hanging upside down by one’s feet, eating thousands of insects per night, and so on. But though these imaginings might help someone understand some aspects of bat behaviour, they don’t elucidate what it is like to be a bat. The nature of a bat’s experience of itself and the world remains frustratingly out of reach.
Consideration of a bat makes the point especially vivid, but the basic point generalises: Facts about experience seem to be inaccessible to someone who is unable to have relevantly similar kinds of experience. For this reason, they also seem unable to be captured within a scientific worldview. While scientific facts are wholly objective, facts about experience are inescapably subjective. Experience thus seems to pose a problem for physicalism, the view that mental states are physical states – a view that’s widely endorsed by philosophers and laypersons alike.
In the almost fifty years since Nagel published his paper, the bat example has featured significantly in discussions in philosophy of mind concerning the adequacy of physicalism and, more generally, in discussions concerning the question of the nature of mind and its relationship to the brain and body. But the example of the bat also raises interesting questions with respect to a wholly different set of issues in philosophy of mind, namely, those concerning the nature and scope of imagination. Suppose that we grant that, given that our sensory capacities are so different from the bat’s, we can’t experience anything like what the bat experiences. Still, one might wonder why this also means that we can’t imagine anything like what the bat experiences. Even if we lack experiential access to what it’s like to be a bat, why do we also lack imaginative access to what it’s like to be a bat?
This apparent limitation on imagination seems especially puzzling when we think about the vast freedom that we tend to enjoy with respect to imagination. As children, we call upon imagination when playing games of pretend. The sofas become islands and the carpet below a shimmering flow of hot lava. A cardboard box becomes a rocket ship, and one’s playmates become aliens and astronauts. As adults, when mired in boring meetings, we imaginatively transport ourselves to tropical vacation spots where the sun shines and the ocean beckons. Scientific and technological progress owes to imaginative breakthroughs by thinkers such as Albert Einstein, Leonardo da Vinci, or Nikola Tesla – all of whom explicitly credit imagination as being critically important to their success. The eighteenth-century Scottish philosopher David Hume even claimed in his Treatise that we’re nowhere more free than in our imaginations.
So, on the one hand, we have a sense of human imagination as unbounded, and on the other hand, we have a sense that certain scenarios lie outside imagination’s reach. How are we to settle this conflict?
To sort things out, it will help to think a little more about the nature of imagination, and in particular, to contrast it with other mental states such as perception and belief. Right now, as I look around me, I can see various things scattered across my desk: a water bottle, a set of keys, a bunch of books, an iPhone … I can also imagine various other things scattered across my desk: an apple, a Rubik’s cube, even a contented cat. But try as I might, I can’t right now see a contented cat on my desk. Given that there is no cat there, there’s nothing I can do to make myself see one.
There are two related points here. First, imagination seems to be voluntary in a way that perception is not. Generally speaking, all I need to do to imagine some thing or scenario is to decide to do so. Second, perception is dependent on the world (or, as philosophers often put the point, is world-sensitive) in a way that imagination is not. And because of this, our powers of imagination seem considerably more unconstrained than our powers of perception.
We can see a related contrast when we consider imagination and belief. Belief, like perception, is also not under our voluntary control. Try as you might, you can’t bring yourself to believe that there is a contented cat on your desk just by strength of will. What about world-sensitivity? Here things are slightly different from they were with the case of perception, since beliefs aren’t world-sensitive in quite the way that perceptions are: Despite our best efforts, most of us undoubtedly have lots of false beliefs. But beliefs still seem more closely tied to the world than imaginings are. In particular, it seems that in forming our beliefs we aim to represent the world accurately. We’re not always successful in this aim, as just noted, but it nonetheless seems that it’s a fundamental aspect of belief, part of what makes something a belief as opposed to some other kind of mental state, that it aims to be true.
Imaginings, in contrast, have no such aim. Though beliefs that falsely represent the world are by their nature defective in some way, imaginings that falsely represent the world are not. There’s nothing wrong with my imagining that a cat is contentedly sleeping atop my desk, or even with my imagining that a purple cat is contentedly sleeping atop my desk, even when my desk is completely devoid of cats. So just as our powers of imagination seem considerably less constrained than our powers of perception, our powers of imagination also seem considerably less constrained than our powers of belief.
Given that imagination doesn’t aim itself at truth, we might naturally wonder: Does it aim itself at anything? Here one standard line suggests that imagination aims at possibility. While belief aims at what’s actually true, what’s true in the actual world, it has seemed plausible to many philosophers to construe imagination as aiming at what’s possibly true, what’s true in some possible world.
Initially, this might seem like an odd suggestion, since we seem to imagine all sorts of impossible things and scenarios all the time. Pigs can’t speak English, for example, yet many authors from E.B. White to George Orwell have imagined them doing so, as have the readers of books such as Charlotte’s Web and Animal Farm. But the sense in which talking pigs are impossible is a sense of biological or physical possibility. The respect in which it seems that our imaginings aim at the possible is a different sense of possibility, namely, logical possibility. Though we can imagine talking pigs and purple cats, it doesn’t seem that we can imagine an animal that is at once wholly purple and wholly green. Round squares, married bachelors – all of these logically impossible scenarios and objects seem to lie outside the capabilities of imagination. Sure, we can imagine a shape that’s squarish with rounded corners, but that is not actually to imagine a round square.
Not all philosophers agree that we’re unable to imagine the logically impossible. In a recent paper, Graham Priest suggests that he has no problem imagining that deep in a trench at the bottom of the Pacific Ocean there lies a pearl that is both round and square. In an earlier paper, Tamar Gendler constructs a story in which it’s true both that five plus seven make twelve and that five plus seven do not make twelve. On her view, readers of the story are able to imagine this logically impossible scenario. Finally, consider the famous picture Ascending and Descending by M.C. Escher. In this drawing, Escher depicts a group of monk-like figures on a circular staircase. For every ascending monk, it appears that if he continues climbing the staircase, he will return to his starting point without ever having to descend (and likewise, every descending monk can apparently return to his starting point without ever having to ascend). Though this kind of staircase is clearly impossible, it seems fairly uncontroversial that one can imagine such a staircase: All one has to do is imagine the staircase as depicted in the Escher drawing.
More to the point: Even if our imaginations were limited by logical possibility, that wouldn’t really give us any kind of explanation for why we can’t imagine what it’s like to be a bat. Bat experience is not only logically possible, it’s actual! And given our discussion so far about the nature of imagination, it seems that all we should have to do to imagine bat experience is to decide to do so. After all, that’s all we have to do to imagine a purple cat or a talking pig. Why, then, would bat experience entirely elude our imaginative reach?
Here it may help to return to Hume. Despite asserting that our powers of imagination are vast, Hume did not think they were limitless. In Hume’s view, all that imagination has to work with are the ideas that have been provided to us by our prior experiences, and though we might recombine those ideas in new and interesting ways, even in imagination we can’t get beyond them. Nagel seems to think something similar, noting that our experience “provides the basic material for our imagination, whose range is therefore limited”. When I try to imagine what it’s like to be a bat, “I am restricted to the resources of my own mind, and those resources are inadequate to the task”. No matter how much I try to imagine additions, subtractions, or modifications to my own experience, I won’t be able to escape my own subjective perspective.
If this is right, then it’s not just bat experience that will be out of imaginative reach. Anything that exceeds a person’s experiential resources will also be unimaginable to her. Indeed, we can find a wide range of examples in the philosophical literature pointing to a similar sort of limit on imagination. A famous discussion by Frank Jackson suggests that someone who has never been exposed to colour sensation would be unable to imagine what seeing red is like. A more recent discussion by L.A. Paul suggests that someone who is childless would be unable to imagine what being a parent is like.
It’s exactly at this point that I would urge we should push back. To my mind, our imaginative capabilities are a lot more powerful than these philosophers give them credit for. There’s at least one important fact about imagination to which they might have been insufficiently attentive: Imagination is a skill. Some people are better at it than others. The fact that one person, or even many people, can’t imagine what it’s like to be a parent prior to becoming one, for example, doesn’t mean that no one is able to do it. Likewise for being a bat. Yet, just as the contortions achievable by a skilled acrobat can seem unfathomable to someone who is not a skilled acrobat, the imaginative contortions achievable by a skilled imaginer might well seem unfathomable to someone who is not a skilled imaginer. Thus, those of us who are not particularly skilled imaginers should be careful of drawing mistaken inferences about imaginability in principle based on our own imaginative limitations.
Consider animal scientist Temple Grandin – someone who is not only a particularly gifted imaginer but who is also particularly gifted at talking about her imaginative experiences. In her memoir Thinking in Pictures, in a fascinating discussion of how she designs cattle-handling equipment, Grandin describes how she trained herself to be able to take a cow’s eye view of various situations. As she describes it, she is able to imagine exactly what a cow is feeling in certain unfamiliar surroundings. Her great success at developing innovative and effective designs supports this self-assessment. While the leap from cows to bats is not a trivial one, it’s not such a longshot that someone who knows as much about bats as Grandin knows about cow might well be able to take a bat’s eye (or ear) view of a situation as well.
In thinking about imaginative limitations, another important consideration stems from the fact that our experiential resources might not be quite as impoverished as is sometimes claimed. From virtual reality games to echolocation training exercises, people have access to considerably more bat-like experiences than is often assumed.
Relatedly, skilled imaginers are often particularly good at a process I refer to as imaginative scaffolding, leveraging various experiences in imagination in an effort to reach new ones. Before becoming a parent, one hasn’t experienced the intensity and all-consumingness of parental love before – and that’s a big part of what many non-parents find so difficult to imagine. But a skilled imaginer who has experienced all sorts of different kinds of love – from romantic love to love for a sibling to love for a pet – can scaffold out from these experiences to come to understand, in imagination, what parental love feels like.
At this point, the skeptic will undoubtedly retort: But how can we ever really know whether we’ve imagined these things correctly? How could we ever know whether we’ve really imagined what it’s like to be a bat? But such questions seem to me somewhat overly demanding. We should be no more concerned about our ability to judge success at these kinds of imaginings than we are at any others, including the mundane imaginings of everyday life. How does a child know that she’s really imagined hot lava correctly? How does an interior designer know that she’s really imagined correctly how a certain sofa will look in the living room? How does a daydreaming office worker know that she’s really imagined correctly what a vacation to the tropics would be like? None of these situations are ones in which skeptical worries would normally take hold. Why is the bat case so different?
Insofar as skeptical worries do arise with respect to more mundane imaginings, matters can sometimes be settled after the fact. When the couch finally arrives, and when the vacation is finally in progress, the interior designer and the office worker can judge whether their imaginative assessments stand up. In some cases, it will undoubtedly turn out that the imaginative exercises were poorly executed. But in other cases, it will undoubtedly turn out that matters were just as had been imagined.
In the same way, when Grandin builds cattle-handling equipment on the basis of her imaginings, and when the cows react to the equipment exactly as she’s imagined, this all provides support for the fact that she really did imagine a cow’s eye view of the relevant situation. When a new parent feels the surge of parental love for the first time, she can judge for herself whether or not her prior imaginings were accurate. As for someone who’s imagining what it’s like to be a bat, it’s hard to know exactly the context in which this kind of imagining would arise. But whatever the context, there are very likely similar outcomes that can shed light on the accuracy of this kind of imagining as well.
None of this is to say that these imaginings are easy. But just as we can improve other skills via concentrated practice and hard work, I’d suggest we can also become better at imagining via concentrated practice and hard work. There may indeed be some restrictions on human imaginative capacity; nothing that I’ve said here suggests that our powers are completely without limit. But there’s good reason to think that these powers are considerably less constrained than many philosophers would have us believe. When it comes to imaginative exploration, there’s plenty of room to boldly go where no one has gone before.