of Dieks. It is a theorem, derived from other fundamental assumptions. In Dieks, they may never have been born and the end of the human race is independent of their birth order number. A proposition related to the SIA, but not the SIA itself, can be derived from these assumptions. Hence, no one assumes the SIA. It should be called the Self-Indication Corollary, perhaps. SIA's own doomsday argument Katja Grace argues that while SIA overcomes the standard doomsday argument, when combined with an assumption of a Great Filter, SIA leads to another kind of doomsday prediction. The reasoning is as follows. In some worlds, the filter may be early—some time before the advent of a technological civilization like ours. In other worlds, the filter may be late—between the advent of technological civilization and galactic colonization. Collectively, the worlds with mostly late filters have many more instances of life at the human level of development, so SIA, together with the knowledge that we are at the human-level stage, implies we're probably in one of the worlds with a late filter. In other words, the risk of extinction is higher than we would have naively supposed. Notes External links 2005 version of Dennis Dieks's refutation (Requires a PostScript viewer.) 2001 version of Dennis Dieks's refutation in pdf Analysis of the SIA by Milan M. Ćirković (Finds no compelling reason to accept the Self-Indication Assumption, and suggests that some of its consequences are implausible.) Probabilistic arguments