There is tongue-in-cheek behind the line. Recall how Horatio replied to the question of whether he's there: "a piece of him." That's why he only believes it in part, he's only partly there. How else could he believe it, than "in part." He can't believe it all, because he isn't all there. | There is tongue-in-cheek behind the line. Recall how Horatio replied to the question of whether he's there: "a piece of him." That's why he only believes it in part, he's only partly there. How else could he believe it, than "in part." He can't believe it all, because he isn't all there. |