"Let me see book!"
Astonished at the now unexpected request, Eric handed him the much bethumbed volume over which he had struggled so hard. The old man skimmed through its pages, nodding his head from time to time and mumbling in a satisfied way. Then, like a man driving in a nail, he pounded Eric with question after question. He seemed to be asking them from the book, but Eric knew that none of the problems had their origin in it, for they dealt with the work he had been doing in the little cottage by the sea. Yet to almost every one the boy returned a correct answer, or at least, one which was correct in its approach. For two long hours the puzzle-maker questioned him, without ever a minute's let up. At the end of it, Eric was as limp as a rag. At last the old man laid down the book.
"When your examination is?" he asked.
"Next June," the boy replied.
"You can pass him now."
Eric stared at the old man with wild surprise in his gaze and with a down-dropped jaw.
"But I haven't even started on the second half of the book," he said. "And I've got to do it all!"
"You pass him now," was the quiet answer. "The second part—you have done him, too. Learn rules, if you like. No matter. You know him. See!"
He showed the very last set of examples in the book and Eric recognized problems of the kind he had been doing, all unwitting to himself.
"Mathematics not to learn," he said, "he is to think. You now can think. To know a rule, to do sum—bah! he is nothing! To know why a rule and because a sum—he is much. You do him."