Philosophy Phriday: Personal Identity and Personal Idantity

The Daily Ant hosts a weekly series, Philosophy Phridays, in which real philosophers share their thoughts at the intersection of ants and philosophy. This is the fifty-fifth contribution in the series, submitted by Dr. Danny Weltman.

Personal Identity and Personal Idantity

In the movie Antz, the worker ant Z-4195 regards hundreds of ants all dully dancing in the same shuffling motion and moans “why does everybody have to dance the same way? It’s completely boring. It’s monotonous.” In the ant colony depicted in the movie, all the worker ants are more or less the same, which is why they only get numbers for names. But, of course, all the workers are different from each other, too. They each have their own number, at least. If they’re all basically the same, what makes them different from each other?

Dancing antz.

When philosophers ask this question about human beings, it’s known as the question of personal identity. Personal identity is about what makes you you, rather than someone else.

More specifically, there are two kinds of identity that philosophers are interested in: qualitative identity and numerical identity. Qualitative identity is about how similar or different two things are in terms of their various traits. If on Monday I have a neat haircut, professional clothes, and no piercings, while on Wednesday I have a neon-colored spiky mohawk, a patch-covered blazer, and many new piercings, then Danny on Monday and Danny on Wednesday are qualitatively very different. If I’m styled the same on Wednesday as I was on Monday, then Danny Monday and Danny Wednesday are qualitatively very similar.

Numerical identity, meanwhile, is about being the same thing, even if its properties change. On Monday I’m Danny and on Wednesday I’m still Danny, even though many of my qualities changed. All the worker ants in Antz are qualitatively very similar, but they are numerically different: that’s why they all have a different number! If they were numerically the same, they’d all have the same number, so we’d have just one ant with one number rather than thousands of ants with thousands of numbers.

Personal identity is not about what makes people qualitatively identical. It’s about what makes people numerically identical. When I said that I was Danny on Monday and Danny on Wednesday, why was that true? In other words, what makes me me, rather than you? Why do I wake up in the morning as Danny and not as someone else?

Maybe these ants have souls? Image: Alex Wild

One answer is to say that it’s my soul that makes me who I am. A lot of philosophers aren’t huge fans of this answer, because there is not a lot of evidence for the existence of souls. Absent some sort of religious conviction, it’s hard to see why we would believe in souls, and a lot of philosophers want answers that don’t depend on accepting any particular religious dogma.

Another natural answer is that it is our bodies that make us who we are. But some parts of our body seem more crucial than others. If you and I swap brains, we are tempted to say that each of us has a new body, not that each of us has a new brain. That is, it looks like I go along with my brain (and you go along with your brain). Is the brain is the source of personal identity?

Imagine my brain being split in half and put into two different bodies. Which of the two people is me? Is it the part with my left brain, or my right brain? It seems arbitrary to pick one or the other, and I can’t be both people, because they are living their separate lives and doing separate things.

So, faced with the prospect of brain bisection and other strange stuff, we might look for a different theory, one that’s not tied to our physical brains but instead to our personalities. Maybe my memories, desires, goals, thoughts, and feelings make me who I am. Think of the movie Freaky Friday, in which a mother and her daughter swap bodies. In that movie, psychology rather than biology is determining personal identity. The mother and daughter don’t swap brains. They merely swap personalities.

Phreaky Phriday. Image: Alex Wild

But, the psychological view seems to have the same problem as the physical view when it comes to splitting someone in half. If each of the two new people has the same psychology, we get the same problem, but this time attached to their thoughts instead of the physical brain itself.

For this reason and many others, a few philosophers reject personal identity all together: the self is an illusion, they say, and there’s nothing that makes me me and you you because there’s not really such a thing as me or you. There are only thoughts that constantly change, and ultimately nothing ties them together except that we give names to some groups of those thoughts.

What does all this have to do with Z-4195 and his fellow worker ants? Some of our theories of personal identity seem to work less well when we apply them to ants and other non-human animals than they do when we apply them to people. The soul theory can’t tell one ant apart from another ant unless we say that ants have souls, which some religions are not going to be happy with. If those religions can still tell ants apart without souls, though, this suggests we could do the same thing with humans.

The body/brain theory works just fine for ants, but the psychological theory is something of a question mark. What sort of psychology does an ant have? In the movie, Z-4195 is a Woody Allen type, full of neuroticism and dissatisfaction, but we might think it’s a stretch to attribute these kinds of attitudes to actual ants or to many other non-humans. So, again, if we can tell ants apart without the psychological theory, maybe we can do the same for humans.

So, does this mean we should go with the body/brain theory, because it works for ants? Or what about the no self theory, which also works for ants? Or even some other theory I haven’t mentioned? This is a pretty complicated topic, and philosophers can’t even all agree on a theory that works well for humans, let alone one that would also make sense in light of ants and other creatures. I lean towards the no self view, which can be traced back to luminaries like David Hume and the Buddha. All I can suggest right now, though, is that whatever answer we pick, it’s worth making sure either that it works for ants, too, or that we have some good reason for excluding ants (and everyone but humans, in fact!) from the discussion. Traditionally the debate has parochially only focused on humans. Z-4195 and his friends matter just as much as you or I!

Further Reading

A great place to start on personal identity is John Perry’s A Dialogue on Personal Identity and Immortality. Perry also edited a book titled Personal Identity full of important works on the topic. The free online Stanford Encyclopedia of Philosophy has helpful entries that you can find if you search “personal identity.” Last but not least, part three of Derek Parfit’s book Reasons and Persons is a detailed and interesting look at the topic which is halfway between the psychological view and the no self view.

Danny Weltman Phil WebsiteDr. Danny Weltman is an Assistant Professor of Philosophy at Ashoka University. He received his PhD in Philosophy from University of California San Diego in 2018. Dr. Weltman works primarily in political philosophy on topics like self-determination, secession, colonialism, annexation, immigration, and cosmopolitanism. He is also interested in topics including personal identity and ethics, and the philosophy of political science.