The Wonderful Capacities of Other Animals

“As dogs, cats, horses, and probably all the higher animals, even birds have vivid dreams, we must admit that they possess some power of imagination.” —Charles Darwin, Descent of Man

Darwin’s evolutionary theory did more than establish a corporeal commonality between species; it also raised hard questions about commonalities of consciousness. David Peña-Guzmán, cohost of the philosophy podcast Overthink and author of Chimpanzee Rights: The Philosophers’ Brief pushes deep into those questions in his recent When Animals Dream: The Hidden World of Animal Consciousness. If other animals dream like us and imagine like us, he asks, what else can we infer, or suspect, or demonstrate about their consciousness? Does the world matter to them in some of the same ways it matters to us? And if so, how should that kind of mattering then in turn matter to us humans? David explores these questions and others in a recent Recall This Book conversation (available via Apple and Spotify).

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John Plotz (JP): Could you start by framing your book’s key ideas and pointing toward what you think has been controversial or influential in the reception of your work?

David Peña-Guzman (DPG): The quote from Darwin that you began with is a great way of contextualizing and historicizing my book because I see myself as working in the heels of this way of thinking that we inherit from the 19th century, and to which in some ways I believe that we need to return. This way of thinking foregrounds animals as complete subjects, which is to say, as agents who have a lot of similarities with human beings, but also a lot of differences.

In The Descent of Man, Darwin introduces his Victorian readers to a whole spectrum of emotions, concepts, inferential capacities that we thought we were the only ones to possess in the entire world. And he shows that, in fact, many other nonhuman animals also experience emotions such as anger, jealousy, and joy, and that they have impressive cognitive skills. They can differentiate between same and different, and between friend and foe. They even make rational inferences that suggest a certain rationality orders their minds.

My work tries to continue this way of thinking about the subjectivity of nonhuman animals by taking a very specific capacity as its focus. And that is the capacity to dream.

I use dreaming, which is a fascinating thing that brains, and nervous systems, and organisms do, as a window into the minds of other animals that share this capacity with us. And so, the book is an exploration of animal consciousness that presents animals as what I call “world builders.” What I mean by that is that animals are world builders not only in the strict ecological sense that they literally leave their mark in physical space (by building nests, caves, and all kinds of dwelling spaces), but also in the deeper philosophical sense that they build their own world of experience out of their cognitive, emotional, social, and sensory capacities.

If you bring together my interest in Darwinian thinking with the fact that I am trained as a philosopher, that gives you a sense of the kind of book that this is. It is a philosophical interpretation of biological subjectivity.

JP: Can I pick up on two different ways that you characterized the importance of what dreaming shows? The first is about basically sensory or subjective commonality, or the notion that the feeling and experiencing that humans have is echoed in the feeling and experience that animals have. The other is the point about how we can see proof of animal rationality.

Those are distinct points, and one could potentially see them heading in different directions. One emphasizes sensibility as the crucial connection and the other emphasizes cognition, like the proof that cognition that we think of as unique to humans actually occurs in other animals. Would you explain those two different aspects of the argument you’re making?

DPG: These two terms—sensibility and rationality—capture different traditions in the history of philosophy for thinking about the nonhuman animal. There is a tradition that foregrounds feelings, the senses, and the operations of the body. And there’s another that foregrounds questions of rationality, conceptuality, and language. These traditions lead to very different conclusions about the lives of animals, depending on how they get cashed out.

As a philosopher interested in how we think about nature, one of my worries is that when we put too much weight or too much value on things like rationality and language, and treat them as preconditions for sentience, consciousness, or moral value, we end up producing a lot of false negatives. That is to say, we draw the false and erroneous conclusion that a lot of other species—from insects, to cephalopods, all the way to other mammals—simply don’t have that rich inner world, a first-person experience.

This is why, in my book, I lean toward thinking about experience in terms of sensibility, embodiment, affect, and emotion—because I think that’s where the real value of animal life lies, and not in these other high-end, high-order cognitive capacities. But you’re right that in the book, I do also talk about those cognitive dimensions in connection to dreaming. But I am committed to the claim that what makes us and other animals matter from a moral point of view is not the possession of reason or language or conceptuality. Rather, it is our capacity to feel the world on an affective, corporeal, and embodied level. And I use this framework to interpret the dreams of other animals, which are subjective and affective more so than rational and logical.

In fact, one thing we can agree upon about dreams is that they are highly illogical at times. And yet—and this is the important part—they teach us something about how the minds of other animals operate. They are fleeting windows into their subjectivity.

I link dreaming, consciousness, and ethics to show that we humans have a moral obligation to reconfigure how we relate to nonhuman animals.

JP: Can you say a little bit more about the notion of dreaming as world building and why you feel confident that is something that’s going on in animal dreaming as well?

DPG: I cite a lot of research from animal sleep indicating that many other animals also experience the nightly visions that we call dreaming. When they go to sleep, there is a spike in mental and corporeal activity that suggests there is a whole world that is imagined or (to use a metaphor from magic) conjured up by the animal. This conjuring act is something we do all the time. But it’s also something that many other mammals do. And it’s something that plenty of nonmammals do too, including birds, fish, and cephalopods. It’s a capacity that is quite widespread throughout the animal kingdom. For example, I talk quite a bit about the dreams of octopuses and cuttlefish.

After laying out evidence of dreaming in other species, the book then teases out the philosophical implications of this phenomenon. Once we know that other animals dream, what exactly follows? What does it tell us about their capacity for memory, about their capacity for subjective experience? What does it teach us about their ability to imagine things that are not real?

I find these questions fascinating from a philosophical point of view and, ultimately, they led me to the notion of animal “world building.” We know that the world that we experience while awake has a very close connection to objective reality. We perceive the external world. We interact with things outside of our mind, things that are mind independent. But we also know that our experience of this reality isn’t simple. It is colored by the activity of our own mind, which adds details to this world. Our minds are creative. It is the things that the mind creates, that the mind constructs, that ultimately become the stuff of our lived experience. Although this creative element is always at play in our experience, it displays itself with unrivaled clarity in our dreams, which are mental creations par excellence.

JP: All of us have probably seen what happens when dogs dream. But you have wonderful examples of, for example, chimpanzees who seem to be signing in the sign language humans taught them to use when awake.

But you’re also interested in the ways in which we’ve been able to study humans while sleeping extrinsically. Not just recording our own dreams but looking at what a human brain looks like under sleep. Could you talk us through some of the evidence that makes you feel pretty confident about the deep commonality between animal dream experience and human dream experience?

DPG: Let me begin answering this question by noting a difficulty I faced while writing this book. Typically, when we want to know whether somebody dreams, we simply ask them and we get a report. But that is not possible in the case of nonhuman animals, given that we don’t share a linguistic schema. In trying to figure out whether other animals do or don’t experience dreams, we have no choice but to rely on extrinsic markers.

Those markers are of two orders. There are markers that have to do with what you have just referenced, which are oneiric behaviors. The term oneiric is the adjectival form of the ancient Greek root oneiros, which means dreaming. So oneiric behaviors are dream-related or dream-indicating behaviors. They include things like moving our bodies in particular ways during asleep, especially ways that seem to match what our dream body is doing in the dream world.

 It also includes facial gestures and vocalizations that can be signs of what’s happening in a dream. This is where I talk about, for instance, research from primatology suggesting that chimpanzees that have been trained to speak using American Sign Language (ASL) will sign in their sleep during REM, which might mean that they’re having entire conversations with some imagined interlocutor in their dreams. We don’t know who those interlocutors are. We may never know the precise layout of their dream world. But on the basis of this research, we can hypothesize that their dreams likely include communicative and therefore symbolic content.

And so, one side of the evidence has to do with all these oneiric behaviors, but the other side has to do with those signatures of neural activity that you mentioned. Patterns of neuronal activation that allow us to establish very important parallels between the waking state and the dreaming state. For example, when animals perform certain behaviors that are highly significant and important for their social and their cultural lives, those behaviors often trigger a specific neural signature. Every time you see that behavior, you find the signature associated with it. If you then suddenly spot that exact same neural signature in the context of sleep, you now have reason to believe that the animal is mentally “replaying” or “rehearsing” that behavior and that this replay may take the form of a dream.

I also talk about research with birds where the neural signature for certain songs reappear in their sleep, suggesting that they’re dreaming of practicing their own song.

JP: I really love that you quoted John Dryden on that: “The little birds in dreams, their songs repeat.” It’s another example of this notion of historical recurrence: These are truths that humans have known about animals for centuries, but for some reason didn’t want to face up to.

DPG: If you look at the history of writings on animals, you’ll see that a lot of ideas about what animals can do, how they behave, and what they feel have been rejected at various moments based on the configuration of scientific knowledge at that time. But as the configuration of knowledge changes, suddenly we can look at old things through new eyes. And this is the case with this particular reference about birdsong, which I was very happy to find. Birds don’t just sing their songs when they’re awake. They also sing them quietly in their dreams.

JP: You talk about the period of the 1870s and 1880s, and a George John Romanes book called Mental Evolution in Animals from 1883, which you suggest is pointing towards a more capacious way of thinking about animal consciousness. And then you say there’s a silent century that follows that. What’s changed recently that has let the silence of that century be opened up a little bit, to let those voices back in?

DPG: I do tell this story of a, let’s say, “loud” 19th century when experts feel free to express wonder at the beauty of nature and the magnificent capacities of other animals. But things then change. At the start of the 20th century, there is a shift, especially in psychology, that causes a lot of people interested in animals to turn away from that curiosity that was normal in the 19th century and to focus exclusively on what can be measured and quantified. So, instead of talking about the inner lives of animals, experts only talk about what can be observed externally.

This gives rise to what is known as behaviorism, which basically says, “Look, we don’t really know what’s going on in the minds of animals. We can’t even say that they have a mind. So, let’s just bracket all of that and exclusively focus on what they do.” That had a flattening and impoverishing effect on the animal sciences because it took away our capacity to think of animals as agents, as subjects.

JP: Do you have an overarching account of why it would be in the 1970s and 1980s that behaviorism would wane?

DPG: I talk about what is known as the “cognitive revolution” in psychology that started in the 1950s, and whose consequences weren’t really felt until the 1970s. And this was the recognition on the part of psychologists themselves that you cannot talk about certain things unless you posit the existence of mental states and unless you start becoming curious about mental processes. You cannot dismiss the mind. You have to think about how it functions. Of course, there is a highly complex, beautifully complex relationship between mind and body, but you lose that beauty if you cut out either element.

We have already rejected the idea that we are disembodied minds in the Cartesian sense. But for a minute there, we were tempted by the opposite or inverse notion, which is that we are bodies without minds. Eventually, it was psychologists who became aware of the limits of behaviorism and realized that they wanted to have more to say about animals than behaviorism allowed.

JP: Your final chapter, “The Value of Animal Consciousness,” is a place where you put some ethical cards on the table, and maybe it would get us to questions about what I framed at the beginning as why what matters to animals should matter to us.

I’ll start with a claim that you make about moral status. You say, “Our moral status comes from our primordial bond with the world, where our sensations, affects, and emotions comingle with one another in an endless dance. Located within experience but outside the reach of cognition, this bond is what remains once we have peeled away the abstractions of reason and the schemas of language. It is our moral and existential bedrock.” Would you parse the implications of this?

DPG: In ethical theory, one of the central questions is: Who is a subject that matters? To whom do ethics and morality apply? And that question is often articulated through the language of moral status. Which of the things that exist in the universe have moral status?

Now most of us have, let’s say, a folk understanding of where the lines are to be drawn in general terms. For instance, right in front of me at this moment of recording, I have a cup of coffee, I have a pen, and I have a set of keys. Most of us agree without any deliberation, without any argument, that these things are not moral agents. They don’t have rights. They don’t matter from a moral point of view.

When we talk about our fellow humans, most of us agree that, well, that’s a clear Yes. I would hope all of us agree on that point. But some people have historically had prejudiced views that exclude certain humans, that exclude women, that exclude racial minorities and people with disabilities from that category.

JP: One of the phrases you use is “morally considerable.” “Considerable” suggests a certain kind of grayscale, like there isn’t just one way that moral consideration can work. I mean, you could imagine moral consideration for a flea, a dog, and a human as being different even though they were all “considerable.”

DPG: We can think about the phrase “morally considerable” as referring to who gets to have a seat at the table where we discuss what needs to happen in order to live in a moral world. It doesn’t mean that we reach the same conclusions about everybody in that room because different organisms have different needs. They have different interests. And they are harmed in different ways.

For example, mammals that are raised by a caretaker are deeply harmed by maternal separation, but there are animals who are separated from their progenitors from the moment they hatch. For them, maternal separation is not an injury. It’s not an issue. So, the point is not that all animals should have exactly the same moral protections.

The gray area really concerns which nonhuman animals should be protected. Should all nonhuman animals have moral rights, or only some? What I try to do in this book is lean on the capacity to dream as a key that opens the lock to that room of moral considerability. If you’re the kind of entity that has dreams, that can dream, independently of what you dream about, you have the right to go into that room and have your interests be taken into account. Because to dream is to be conscious of the world. It is to have consciousness, and sentience, and sensibility. It is impossible to dream without having those things. That’s really the core argument. It is logically inconceivable that there would be a dreamer that is completely devoid of consciousness. It simply does not work.

I link dreaming, consciousness, and ethics to show that we humans have a moral obligation to reconfigure how we relate to nonhuman animals, to treat them differently, to respect their interests, and maybe to codify those interests in the form of legal rights. And one way to decide which animals get included is by looking at dreaming.

I use science, recognizing that it’s a morally compromised and imperfect answer to the dilemma. And I react to it by not calling for further research on the subject. What we have is more than enough to see animals in this new light.

JP: You make an allusion to factory farming. But you also mention invasive scientific research. That’s an interesting move, given that it’s a book that is responding to and in dialogue with scientific research, which to some extent presumably does depend on the invasive. How do you think about the ethical claim around invasive scientific research?

DPG: The most honest answer I can give you is that I have felt a sense of tragedy around the writing of this book. I mean tragedy in the sense that, in order to make this argument, I couldn’t avoid engaging scientific research that doesn’t meet the conditions of morality that I would want scientific research to meet.

I had to do a little bit of soul-searching when writing this book. I kept going back and forth about whether I should engage this research at all because many of the neuroscientific protocols that I mentioned require, at the very least, keeping animals in captivity. In many cases, they require killing animals and dissecting their brains.

The question for me became: Should I distance myself from the science or should I engage the science in order to articulate an argument that ultimately tries to put further limits on it? And I decided that it would’ve been impossible for me to make the argument I needed to make without engaging the relevant research.

I do think that there is a legitimate criticism there to be made of my overall approach, because I do lean on research whose methods are, from my perspective, unethical. And that was a tragic decision that I had to make where I felt like it was tragic insofar as I had to compromise a principle.

This is something that I’ve experienced in the past, because a lot of my work involves the sciences. And the way in which I’ve justified it to myself is to think of my work as enacting a kind of imminent critique of scientific rationality concerning animals. What I ultimately want to do is tell scientists: By your own findings, these are creatures that are much more complex than you realize, and that therefore might be entitled to protections even from the things that you have done that lead us to appreciate that complexity.

JP: In your case, you’re describing a tragedy because you precisely need to have the evidence of the experiments that you’re studying within bounds in order to be able to make the case that they ought to be out of bounds. Is there a comparable example in the history of philosophy or the history of science of such a tragic dilemma?

DPG: The research on children that was conducted during the Third Reich—this sounds horrible and it sounds justificatory—but we learned some things about children through those horrific experiments. Later, researchers struggled with whether they should even cite that data even if that data was already done and the discoveries were already made. And so, I think that would be comparable.

JP: Let’s say you can save a life by citing data that allows you to know something about a child’s physiology. Is it okay to save that life if the price is that you’re sanctioning a form of unthinkable knowledge?

DPG: Science is rife with moral dilemmas and moral tragedies of all sorts. Science shapes our collective imagination, and that includes our moral sensibilities, which then get used to regulate science itself. And so, I end up using science, recognizing that it’s a morally compromised and imperfect answer to the dilemma. And I react to it by not calling for further research on the subject. I think what we have up until now is more than enough to see animals in this new light.