Whether one's internal experience is subjective or objective is not really germane to the book. Nobody can reach into another person's mind and grasp the totali

Whether one's internal experience is subjective or objective is not really germane to the book. Nobody can reach into another person's mind and grasp the totality of their experience, which makes it effectively subjective even if it is in principle objective. What is relevant is that some minds have internal experiences which are correlated, and that correlation points to an objective reality. If I tell you that the sky is pink, and you look outside and see that it is actually black with white polka-dots, are we in different realities, is one of us a solipsist (meaning that the other doesn't even exist), is one of us insane, or are we just in different time zones? One of these explanations is simplest, of course, but the book is about the others.