@toiletpaper n since nothing can be argued out of it. Doesn't work. Then I try ti argue that since they are in fact arguing, they cannot seriously entertain the idea of solipsism and doubt, since if they did, what point would the be in arguing with a fictional/non-existent entity? Not, that doesn't work either.
Same thing goes with idealists who doubt the external world, yet, when challenged if they doubt gravity, they never dare to tests their non-belief in gravity. I argue that it means some