If SIA is valid, than multiverse is true and all possible minds exist.
However, if all possible minds exist, we can’t use SIA anymore as the fact of my existence is not the evidence for anything.
As a result, SIA is self-defeating: it can be used only to prove multiverse but we can also prove it without SIA.
We can use untypicality argument similar to SIA: the fact that I exist at all is the evidence that there were many attempts to create me. Examples: the habitability of Earth means that there are many non-habitable planets and fine-tuning of the Universe means that there are many other universes with other physical laws.
Note that untypicality argument is not assumption—it is a theorem. It also doesn’t prove infinity of my copies but only very large number of attempts to create, which is practically similar to infinity and can be stretch to “all possible minds exist” if we add that any sufficiently large mind-generating mechanism can’t be stopped: non-habitable planets will continue to appear as they don’t “know” that one is now habitable.
If SIA is valid, than multiverse is true and all possible minds exist.
However, if all possible minds exist, we can’t use SIA anymore as the fact of my existence is not the evidence for anything.
As a result, SIA is self-defeating: it can be used only to prove multiverse but we can also prove it without SIA.
We can use untypicality argument similar to SIA: the fact that I exist at all is the evidence that there were many attempts to create me. Examples: the habitability of Earth means that there are many non-habitable planets and fine-tuning of the Universe means that there are many other universes with other physical laws.
Note that untypicality argument is not assumption—it is a theorem. It also doesn’t prove infinity of my copies but only very large number of attempts to create, which is practically similar to infinity and can be stretch to “all possible minds exist” if we add that any sufficiently large mind-generating mechanism can’t be stopped: non-habitable planets will continue to appear as they don’t “know” that one is now habitable.