ABSTRACT
But what is the force of this “must”? Suppose that while wandering through Wonderland, Alice meets an odd personage (Tweedle Duo) who insists that, yes, indeed, Massachusetts is due west, about thirteen hundred miles; and yes, indeed, it is due east, about thirteen hundred miles; and yes, yes, verily, Massachusetts occupies only one spot on the globe. Once Alice has established that Tweedle Duo’s protestations are sincere, she is bound to conclude that he is “out of his mind.” In other words, he and his mind cannot be at one with each other. In other words, he must not be at one with himself. He is not “of one mind.”
