Imagine that you have a one-time-only chance to become a vampire. With one swift, painless bite, you’ll be permanently transformed into an elegant and fabulous creature of the night. As a member of the Undead, your life will be completely different. You’ll experience a range of intense new sense experiences, you’ll gain immortal strength, speed and power, and you’ll look fantastic in everything you wear. You’ll also need to drink the blood of humanely farmed animals (but not human blood), avoid sunlight, and sleep in a coffin.
Now, suppose that all of your friends, people whose interests, views and lives were similar to yours, have already decided to become vampires. And all of them tell you that they love it. They encourage you to become a vampire too, saying things like: “I’d never go back, even if I could. Life has meaning and a sense of purpose now that it never had when I was human. It’s amazing! But I can’t really explain it to you, a mere human. You’ll have to become a vampire to know what it’s like.”
In this situation, how could you possibly make an informed choice about what to do? For, after all, you cannot know what it is like to become a vampire until you become one. The experience of becoming a vampire is transformative. What I mean by this is that it is an experience that is both radically epistemically new, such that you have to have it in order to know what it will be like for you, and moreover, will change your core personal preferences.
“You’ll have to become a vampire to know what it’s like”
So you can’t rationally choose to become a vampire, but nor can you rationally choose to not become one, if you want to choose based on what you think it would be like to live your life as a vampire. This is because you can’t possibly know what it would be like before you try it. And you can’t possibly know what you’d be missing if you didn’t.
We don’t normally have to consider the choice to become Undead, but the structure of this example generalizes, and this makes trouble for a widely assumed story about how we should make momentous, life-changing choices for ourselves. The story is based on the assumption that, in modern western society, the ideal rational agent is supposed to charge of her own destiny, mapping out the subjective future she hopes to realize by rationally evaluating her options from her authentic, personal point of view. In other words, when we approach major life decisions, we are supposed to introspect on our past experiences and our current desires about what we want our futures to be like in order to guide us in determining our future selves. But if a big life choice is transformative, you can’t know what your future will be like, at least, not in the deeply relevant way that you want to know about it, until you’ve actually undergone the life experience.
Transformative experience cases are special kinds of cases where important ordinary approaches that people try to use to make better decisions, such as making better generalizations based on past experiences, or educating themselves to better evaluate and recognize their true desires or preferences, simply don’t apply. So transformative experience cases are not just cases involving our uncertainty about certain sorts of future experiences. They are special kinds of cases that focus on a distinctive kind of ‘unknowability’—certain important and distinctive values of the lived experiences in our possible futures are fundamentally first-personally unknowable. The problems with knowing what it will be like to undergo life experiences that will transform you can challenge the very coherence of the ordinary way to approach major decisions.
Moreover, the problem with these kinds of choices isn’t just with the unknowability of your future. Transformative experience cases also raise a distinctive kind of decision-theoretic problem for these decisions made for our future selves. Recall the vampire case I started with. The problem here is that, before you change, you are supposed to perform a simulation of how you’d respond to the experience in order to decide whether to change. But the trouble is, who you are changes as you become a vampire.
Think about it: before you become a vampire, you should assess the decision as a human. But you can’t imaginatively put yourself in the shoes of the vampire you will become and imaginatively assess what that future lived experience will be. And, after you have become a vampire, you’ve changed, such that your assessment of your decision now is different from the assessment you made as a human. So the question is, which assessment is the better one? Which view should determine who you become? The view you have when you are human? Or the one you have when you are a vampire.
The questions I’ve been raising here focus on the fictional case of the choice to be come a vampire. But many real-life experiences and the decisions they involve have the very same structure, such as the choice to have one’s first child. In fact, in many ways, the choice to become a parent is just like the choice to become a vampire! (You won’t have to drink any blood, but you will undergo a major transition, and life will never be the same again.)
In many ways, large and small, as we live our lives, we find ourselves confronted with a brute fact about how little we can know about our futures, just when it is most important to us that we do know. If that’s right, then for many big life choices, we only learn what we need to know after we’ve done it, and we change ourselves in the process of doing it. In the end, it may be that the most rational response to this situation is to change the way we frame these big decisions: instead of choosing based on what we think our futures will be like, we should choose based on whether we want to discover who we’ll become.