We don’t know that all possible worlds are actual. This could be the only one.
Indeed. This entire post assumes all possible worlds are actual and reasons from there; I didn’t mean to argue for their existence.
How were you first informed of the existence of numbers, colors, space, time, or people? It wasn’t by non-contradiction.
Correct. But we are quite bad at actually reasoning from the law of non-contradiction; we often tend to act as if we believed contradictory things (as is shown by how frequently we make math errors). I conjecture that that is the reason why we need observation to figure things out (assuming all possible worlds exist), although I am not completely sure.
Indeed. This entire post assumes all possible worlds are actual and reasons from there; I didn’t mean to argue for their existence.
Correct. But we are quite bad at actually reasoning from the law of non-contradiction; we often tend to act as if we believed contradictory things (as is shown by how frequently we make math errors). I conjecture that that is the reason why we need observation to figure things out (assuming all possible worlds exist), although I am not completely sure.