Abstract

The self-indication assumption (SIA) claims that given that one exists, one should think that the universe has many people, for a universe that has more people is more likely to contain any particular person. SIA is attractive to many because it diffuses the infamous doomsday argument, and avoids the problems of its main rival, the self-sampling assumption (SSA), which instructs one to reason as if they’re randomly selected from the people in their reference class. Here, I will go further than the traditional argument for SIA from its ability to avoid the doomsday argument: I will show that any view other than SIA must accept the soundness of the doomsday argument and certain even stranger conclusions. Additionally, I’ll argue that the main objection to SIA, the presumptuous philosopher case, is unconvincing. Together then, these considerations give one a strong reason to adopt SIA.