[H]e never seemed to stop talking, though he never bored us, even if we did sometimes have difficulty in understanding him. . . . He sparkled and scintillated, yet not one of us who listened to him felt that we were being overwhelmed or left out. One of Isaiah’s most priceless attributes is that he evokes genius in others . . . , giving them the impression that they are really more coruscating and witty than they would otherwise believe themselves to be.