that: “To approve or disapprove of the opinions of others is acknowledged, by everybody, to mean no more than to observe their agreement or disagreement with our own.” Yet no one would accept as a definition of error the statement that: Error is any opinion that I personally do not like. Error has thus a very puzzling character. For common sense will readily admit that if a statement is erroneous, it must appear erroneous to every “right mind” that is in possession of the facts. Hence the personal taste of one man is not enough to define it. Else there might be as many sorts of error as there are minds. It is only the “right mind” whose personal taste shall decide what is an error in any particular case. But what then is a normal mind? Who is the right-minded judge? There seems to be danger that common sense shall run at this point into an infinite regress. I say: That opinion is an error. What do I mean? Do I mean that I do not like that opinion? Nay, I mean more. I mean that I ought not to like or to accept it. Why ought I not? Because the ideally right-minded person would not, seeing the given facts, hold that opinion about them. But who is the ideally right-minded person? Well, common sense may answer. It is my ideal person, the right-minded man as I conceive him. But why is my ideal the true ideal? Because I like it? — Nay, because, to the ideal judge, that kind of mind would seem the ideal. But who is the ideal judge? And so common sense is driven from point to point, unable to get to anything definite.
So much, then, to show in general that common
