Fear of death is not exactly fear of death or being dead

You don’t believe in the afterlife. Your doctor tells you that you will die in a week. You are terrified. A couple of minutes later, the doctor comes back, herself looking terrified. She tells you that she has both good news and bad news. The good news is that she had misdiagnosed you—you are just fine. However, the bad news is that her sister who is a cosmologist has just discovered that the everything—the universe, space and time—is coming to an end in a week. (She begs you not to tell anyone, because that will cause a panic.)

Out of nerdy curiosity, you ask the doctor whether there will be a last moment of time. She says that the same question occurred to her, and there won’t be. The interval of time is open on the upper end: for every time t, there is a later time t′. It’s just that time is literally running out, and all the remaining times are less than about a week from now.

With grim amusement you note that you won’t die. For at every time in the future you will be alive, and there won’t even be a last time which one might want to identify as the “time of death”.

You reflect. It’s a bit of a plus that none of your friends will suffer from your death, but a big minus that they all have only a week left. In any case, there is no relief from fear of death.

I think this case shows that it’s not death or being dead that we fear when we don’t believe in an afterlife. We fear the fact that our future is finite. If this is right, then people like Lucretius who thought that we somehow confusedly imagined ourselves as existing after the end of our existence and that this was what explained the fear of death are likely mistaken.

A nearly equivalent version of the above thought experiment would be one where you find out that you’re going to live for an infinite amount of time, but your life will exponentially slow down. In the next week of life, you will experience half a subjective week. In the week after that, you will only experience a quarter of a subjective week, and then an eighth and so on. Your subjective future will be a week. But you will never die. That’s just as bad as permanently dying.