"You know you have a brain the way you know you have a spleen: by hearsay. You are... acquainted... so intimately that you might even say that you are your mind. (That’s what Descartes said: ...he was mind, a res cogitans, or thinking thing.) ...If it occurred to you to wonder whether you... had a mind... you would immediately realize, as Descartes... that your very wondering... demonstrated... that you... have a mind. This suggests that each of us knows exactly one mind from the inside, and no two of us know the same mind from the inside."