I’ve been reading about the Doomsday Argument (DA) and its reliance on the Self-Sampling Assumption (SSA). I would appreciate some insight on an objection I’m struggling to evaluate.
Specifically, why can’t one resist the DA by constraining their reference class to include only currently existing humans, rather than all humans who will ever exist? Under the standard SSA framing, we assume we are random samples from the entire set of humans who will ever live. However, it seems equally reasonable to instead regard ourselves as random samples from the set of currently existing observers.
This narrower reference class aligns well with presentism (the position that only the present exists). From a presentist perspective, future humans do not exist in any real sense. It seems natural to then exclude these future people from probabilistic reasoning.
This move also avoids other counterintuitive implications of the SSA, such as the UN++ hypothetical and the Adam and Eve thought experiment.
I apologize if this question is too philosophy-focused or niche for this forum.
You’re right that with the right reference class, SSA doesn’t imply the doomsday argument. This sensitivity to a choice of reference class is one of the big reasons not to accept SSA.