After coming across a reference to it in a book I was reading on theories of mind (Figments of Reality, to be precise) I decided to dig up and reread Thomas Nagel’s famed essay, “What is it like to be a bat?” Simply expressed, Nagel muses on the impossibility of knowing the experiences of a different mind, for example, that of a bat. Bats are mammals, and share many similar senses and brain structures with their fellow mammal, humans. But their perceptions of the world are largely auditory, where ours are visual. A bat, flying towards a post in the dark, perceives it as its brain interprets the clicks and shrieks of echolocation. A person walking up to that same post in the light of day perceives it based on the brain’s interpretation of variations in wavelength of light reflected off the post. They perceive the same post, but their mental experience of it is likely very different.
I taste a sample of a friend’s cooking. Ugh, I think, coriander. My friend’s experience of coriander is very different from mine (Yum, not ugh). A tiny, minor genetic variant is thought to be responsible for this split between us. A physical difference makes it impossible for us to have the same experience of the same thing. We don’t need to be different species; I can never imagine what she’s experiencing when she tastes coriander and smiles.
Nor can I know how a blind person experiences the world any more than I can put myself into the mind of a whale. The only world I can know is the one I perceive, and I can only guess what others are experiencing. Even if I’m dealing with a person of similar background and sensory abilities, I can’t be sure she hears the same thing I do when we listen to a piece of music. Even if it isn’t coriander effect, and her sensory apparatus is identical to mine, she can still love a particular song that I can’t stand. The brain may be processing precisely the same sound waves, but the mind in residence is not having the same experience of them.
This is a short hop from solipsism. Our isolation inside our own heads can understandably lead to the suspicion that everything outside might be just an illusion, including the existence of other minds. Dear Zeus, has science fiction and literature worn that trope to death! It also makes both appealing and threatening the idea of telepathy. If one could only press one’s fingers to the temple of another being and be reassured that other minds do exist and can be communicated with (simultaneously, it can be profoundly distressing to imagine the primal privacy of one’s mind being breached).
Never mind knowing what it’s like to be a bat; what a leap it would be to know what it’s like to be another person.
The phenomenon of a conscious mind arises out of a staggeringly complex choreography of biology, culture, interaction and experience. The back and forth arms race of evolution has sculpted organisms which are able to make presumptions about what is going on in other minds. Social species depend for their survival on being able to relate to one another. True solipsism is an interesting thought exercise which can get out of hand and lead to mental illness. We make the leap to assume the existence of other minds like ours for the same reason that we assume the world we perceive is real and not an illusion. Those assumptions are necessary for us to succeed and thrive.
So here I am inside my head, trying to figure out what’s going on in your head or the head of the cat who insists on sprawling across my arm as I type. I can use words to try to facilitate communication, but often we can go late into the night trying to reach an agreement and fail because we just don’t see eye to eye. We brood afterwards, frustrated that the other person doesn’t seem to get what we are trying to say about how we feel and what is important to us.
Yet my cat can get me to realize what is on his mind, a desire for food (not that food; ugh) or attention, or his anxiety that I am about to leave (I got out the suitcase or backpack). Empathy and our finely tuned skills of interpretation enable us to make pretty accurate assumptions about the mental states of others and act on them with reasonably good success. The Golden Rule presumes that. I’d be very sad if my wallet were stolen, so I can understand why you would be sad should it happen to you, and it’s good to have rules against theft.
Somehow, imperfectly, we blunder through, making our guesses about what others are experiencing and acting accordingly. Some of us seem to do a much better job than others. I’ll confess I am often utterly defeated by my inability to understand what it’s like to be somebody else, to understand experiences different from my own, to know what their mind expects of my mind and communicate how my mind is experiencing them. It’s exhausting and frustrating.
And yet, when I reflect on how radically individual and isolated all these conscious minds are, I am amazed at how well we do accessing the mind of the other.