As a professor of philosophy I have taught personal identity several times; almost always in introductory classes; mostly via John Locke, David Hume, and the Buddha, and by relying on standard examples in the literature (the Ship of Theseus for instance). Invariably, I begin my class discussions of personal identity by saying something along the lines of, ‘We are used to pointing to a photograph and saying “Hey, that’s me when I was three years (or six months or six weeks) old” and our listeners will believe us in most cases. But what is it that licenses such a claim? The entity we are pointing to doesn’t look exactly like us; it sure doesn’t behave like us; its physical composition is entirely different. So what gives?’ And then, we’re off and rolling. Brain transplantation, teleportation, and the movie Big (among others) follow. I have much sympathy for the ‘forensic’ aspects of personality that Locke alludes to, and for Buddhist and Humean no-self theories, and some of my students, gratifyingly, do cotton on to what it is about these theories that is simultaneously insightful and perplexing. Teaching personal identity allows me, most pleasurably, to delve into topics that are the most close to our hearts but which are often condemned to the margins in the more rarefied regions of philosophy; it is where metaphysics and ethics come together.
These days as I spend most of waking–and sometimes half-awake–hours with my almost-seven-weeks-old daughter, I’m reminded–again and again–of that introductory example of the baby in the photograph. I am aware of her changing, rapidly, all too rapidly. I marvel at her transformation from just-more-than-fetus to infant, as pounds and inches add on, as she starts to respond to more environmental stimuli like sound and light and touch, dishes out ‘social smiles’ when confronted with the cooing expressions of her father, mother, and aunt, and emits sounds, which in the grand imaginations of a hopeful parent, are not just stifled cries but genuine attempts at communication. And I wonder what she will ‘turn into,’ what she will ‘grow up to be’, what she will ‘become.’ I try to extrapolate, sometimes, from her current features, to what she might look like a year from now or even later. I speculate about the friends she will make, and how they will ‘transform’ her so that the girl who leaves home in the morning for school will come back a ‘different’ one in the afternoon.
These speculations run out soon enough, and I urge patience on myself. For I am dimly aware that the girl I play with now, whose crying sometimes almost reduces me too to tears, will not be the ‘same’ girl years later. The one I play with now, who has a nickname I dare not share for fear of being considered soft in the head, will be replaced by someone else. That other girl will look at the gigantic collection of photos her parents put together and perhaps say the same thing: ‘Lookit me – I was kinda cute, wasn’t I?’ She’ll be right, of course. But for now, I want to make sure I make the most of my limited time with this special guest, one who will soon be replaced by another one, as yet another stage of the inevitable process of ‘her growing up’ comes to be.