The body and the mind are constantly changing. Nothing in us is ever really the same from one moment to the next. Yet the self represents a very strong phenomenal experience of sameness, and it’s clear this would be adaptive or helpful for a biological organism that needs to plan for the future. If you want to hide some food for winter or you want to save some money in your bank accounts or work on your reputation, you’re planning for future success and you wouldn’t do that if you didn’t have the very strong feeling that it’s going to be the same entity that gets the reward in the future. [...]
So obviously in a biological or bodily context it may be good to have this experience that all of this, the reaping of the fruits, is going to happen to the same person. But again, strictly speaking, it’s never really happening to the same person, but it’s also not true that there is nobody there. Of course, there is a sufficient similarity over time. We don’t arbitrarily change and it’s kind of a flux. I like very much the image the philosopher Ludwig Wittgenstein once used.
He said you could have a rope—a long rope made of very different strings of different color. And no string, neither the red string nor the blue nor the green one, would go through the whole length of the rope. Yet the rope could be very robust, strong, and stable, even though there is not one thread that goes through it from beginning to end. I think that’s a good image for how we are on the bodily level, as well as on a psychological level.
Despite this, we have robust experiences of autonomy and self- determination. We have the experience of controlling our behavior, and we also have an experience of mental self- determination, controlling our attention, our mental state and all of these things. As modern science shows, these experiences may not be fully veridical, but just adaptive. It may be functional to have the robust experience that you are in control, but from the third person perspective of science, it seems that such experiences may not reflect the truth of our nature. The self is not a thing, but a process.