The Hidden Mental Life of Bats


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October 18, 2022

6 min read


Explaining the mystery of consciousness by contemplating the bat.

Metaphysical Dualism

Thomas Nagel is one of the most important living philosophers. Born in 1939 in Yugoslavia to Jewish immigrants who made their way to the United States, Nagel is well-known for his books The View from Nowhere, Mortal Questions, and The Possibility of Altruism. But his most famous work, "What Is It Like to be a Bat?" explores the separation between mind and body.

The mind-body problem has long plagued philosophy. Is there a difference between the mind and the brain? The traditional approach called "metaphysical dualism" suggests that there are two different sorts of stuff, physical matter, and immaterial souls. Dualism faces a problem of interaction: if mind and body are completely different, how could they influence each other? How does the will of an immaterial mind cause motion in a purely physical body, and how does the interaction of the environment with the body's senses give rise to perceptions?

The success of science has soured many on dualism, elevating materialism, that is, the view that physical matter is the sole constituent of reality, the mind is reduced to the brain. Internal experiences like awe at a beautiful sunset, disgust at the smell of dog feces, and the feeling of love looking at one's family are just the firing of neurons. PET scans show us the brain in action, teaching us what activates when we think and feel.

Nagel argues that correlation does not entail causation. The ability to connect the state of the brain to experience does not answer the hardest question, "What is consciousness?" We need a full account of consciousness, that is, the internal experience of being a self in a world with experiences, beliefs, and desires. Many, including Jewish philosophers from Moses Mendelssohn to Edmund Husserl, have struggled with this question.

But Nagel notes that even if they were successful, the real question still looms because we are asking about consciousness writ large, not just human consciousness. We are not the only conscious beings. Bats, for example, use sonar to locate and swoop in on bugs in the dark with stunning precision. Surely, bats are conscious. But, Nagel says, anyone who has spent some time in an enclosed space with an excited bat knows what it is to encounter a fundamentally alien form of life. Any successful account of consciousness needs to make sense of not only human experiences but those of bats as well.

Any successful account of consciousness needs to make sense of not only human experiences but those of bats as well.

But can we? Our sense of ourselves in the world comes from what we see, hear, smell, taste, and touch. Can we understand what it is like to be a being with entirely different ways of sensing? Their inner life could not make sense to us, so the way they understand themselves would also be inscrutable. But to understand consciousness, Nagel asserts, that is precisely what we must make sense of, something that seems beyond our grasp.

God’s Army

This struggle, it turns out, is Jewish when looking at this problem through the lens of Hannah, mother of the prophet Samuel. In the Book of Samuel, we first come across God called The Host of hosts, deriving from Hannah's petitions to God to note her as a member of God's earthly army, which is to be a general or host led by God, The Host of hosts. In other words, since God is a Host and we are created in God's image, we too must be a creator of hospitality, that is, understanding someone else's needs as your responsibility. For example, Hannah was barren but became pregnant after praying to be noted by God. At that point, she became a host for another life.


Being a member of an army of hosts created in God's image orients Jews toward hospitality for others. The proper way of relating is to identify the needs of the other, and your obligation is to determine how you may be of assistance to them. But that, in turn, requires you to understand needs that are not your own. Indeed, the Hebrew word for other, אחר, is the root of the word for responsibility, אחרות.

This notion was essential in our community from its origins. The children of Israel were an early agricultural society in a world of nomads. Nomadic herders moved through arid lands, grazing their animals following traditional routes. Having one group squatting along the way was a threat to their ability to sustain themselves, and therefore the early Jews could have easily made enemies of their wandering neighbors.

But if these tribes were welcomed and treated as guests, they would then see us as friends. Hospitality inverts the relationship from antagonism to affection. To be in the earthly army of God means being a good host, defusing potential peril, and allowing life on the land to be possible.

The lives of these nomads were radically different from those of the Israelite farmers and herders. Hosting those whose daily struggles are fundamentally different is difficult. This practice became even trickier in the diaspora when the Jewish lot seemed destined to always be strangers in strange lands. We had to maintain our ways while being hospitable to those who saw us as interlopers or invaders. Spreading out across the globe required Jews to see the world through a wide variety of different eyes.

Spreading out across the globe required Jews to see the world through a wide variety of different eyes.

That is where Nagel's challenge - to see the world through a completely different type of eyes - is the ultimate test of Jewish hospitality. We share the world with bats, a world created by God, who directs us to take care of both the environment and those suffering. We are not only responsible for bats but also the bat's habitat; otherwise, the bat, a creature created by God, will suffer from human carelessness. The Torah commands our respect, that is to say, our hospitality for bats and all animals. We should not destroy their habitat. Not only that, but we must do what we can to ensure their survival. But that means understanding who they see themselves as being, or, in the case of bats, hearing themselves as being.

Because bats use sonar in the dark, hearing instead of seeing is the essence of their sense of self. Interestingly, that is the case for Judaism, too. Because we have an invisible God, Jews are unusual in privileging hearing over sight, in contrast to the Hellenic-Christian philosophical tradition. When English speakers understand one another, we say, “I see what you mean.” In Judaism, we hear. For example, Hear O, Israel are the first words of the Shema, our holiest prayer. God sometimes asks, “Where are you?” To which one answers, “Here I am.” In other words, we say aloud: Here I am for you. We identify ourselves through sound.

Thomas Nagel's challenge to know what it is to be a bat was intended to be a punch to materialism in traditional Hellenic-Christian metaphysics, but it turns out in several ways to be a Jewish approach.

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