Anthropic arguments such as this are good for examining reasons why spacetime with a different number of dimensions might not support interesting universes, but they fail to ask answer the question why we have a spacetime with 3 dimensions.<p>Some non-string theory attempts at formulating quantum gravity have started without an assumption of space-time and attempted to make it an emergent property, and given 3-dimensional space&#x27;s quite unique properties that feels like it might ultimately be a better course of reasoning.