I disagree. If there really is only one universe which is 3D, this argument does not in any way explain why it is 3D. If you use Bayesian probability, you woul

I disagree. If there really is only one universe which is 3D, this argument does not in any way explain why it is 3D. If you use Bayesian probability, you would in this case start with p(3d) = 1 since there's only one universe which is 3d and then end with p(3d | life) = 1. In other words, there's no explanatory power in the observation that there's life. If instead you say that p(3d) = 1/1000 because maybe the multiverse has all sorts universes out there but you also say that life is only possible in 3d, i.e. p(life | 3d) > 0, but p(life | not 3d) = 0, then you go from p(3d) = 1/1000 to p(3d | life) = 1. In other words, the observation of life does have explanatory power.