The other argument against the multiverse that I find unconvincing is an appeal to Occam’s razor: it is absurd, some would argue, to hypothesize an infinite number of other universes just to explain our own. It is simplest to assume that only one universe exists. Incidentally, atheists will often say the same thing about God, claiming that it is simpler to assume that just the natural universe exists rather than postulate a complicated entity like God to explain fine-tuning. The problem with both of these arguments is that Occam’s razor does not say that the simplest idea is usually the right one— it says that the simplest explanation is usually the right one.
The problem with this analysis is that Rudelius does not, apparently, know what Occam’s razor actually says. The most commonly cited formulation of the razor is “entia non sunt multiplicanda praeter necessitate” (entities must not be multiplied beyond necessity)*.
Yes, the razor is often shaved down to the “simplest explanation is usually the right one,” but that is not the classical formulation, which speaks of multiplying “entities” beyond necessity.
Now I ask you, is there any greater multiplication of entities than the multiverse? If “infinite universes” does not multiply entities beyond necessity, it is hard to imagine what would.
*In Summa Totius Logicae, i. 12, Ockham also wrote “Frustra fit per plura quod potest fieri per pauciora” (It is futile to do with more things that which can be done with fewer).