A favorite passage from my teacher, Lewis White Beck. It is from his book, The Actor and The Spectator.
Only A. C. Ewing, I think, has indicated a possible transcendental argument against solipsism. He said, “If solipsism is true, there are no solipsists, since I am not one.” This short way with solipsism, almost a throwaway that Ewing consigned to a footnote, seems to me to be profoundly important.
The solipsist position has never been maintained if it is true, because if it is true I alone could have maintained it, and I have not done so…
I believe this argument, invented by Ewing, is likewise usable by others and not discountable when extended to others. This argument will carry no weight, of course, with another person if he is a genuine solipsist who knows his business. But, if there is such a person, I know that solipsism is false since that person is not I.