Thanking the practitioner for her advice, Walter left the house and started home. He was not fully satisfied with his visit; many of the questions he had asked the practitioner remained unanswered, as he supposed, for the practitioner always referred him to "Science and Health." In answer to one of his most important questions, she said, "'Science and Health,' page so and so, says thus--"and then she would quote something from the book, but he could see no connection between his question and the quotation. When he arrived home he decided to tell his father all and try to persuade him to have his mother treated by a Christian Science practitioner. CHAPTER X HUMANITY'S MISTAKE The same evening Walter went into the library to see his father, and found him seated at his desk with his Bible open before him. As Walter seated himself near the desk, his father looked up and asked, "What is it, Walter?" "I came to have a little talk with you, father." "I am glad you did, as there are several questions I wanted to ask you, one of which is in regard to that saying of Jesus Christ--'ye shall know the truth and the truth shall make you free'-you explained before but I did not catch your meaning." "Let us use an illustration to show what is meant by that saying. For instance, supposing we had been taught from childhood that two times two are five, and every person on earth believed this to be right, we would all go through life making this mistake. There would be constant trouble all over the mathematical world because of it, and when we tried to rectify this trouble we would use this same mistake in trying to arrive at a true answer. At times we would deceive ourselves and believe we were right, only to find later on that we were in deeper trouble. And when we had children of our own, we would still teach them the same as we were taught that two times two are five, and the longer the world stood, the greater would become this mistake, as no one knew the truth that two times two were only four; yet all this time the principle of mathematics existed and was correct, but man knew it not. Now father, imagine how great and widespread this mistake would become in several thousands of years, and how hard it would be to convince the people of their mistake, especially the professor of mathematics who had devoted a lifetime to proving that this mistake was the truth. You can readily see it would be much easier for the child who had never learned or believed in the mistake to grasp this truth than the professor who believed that the mistake was correct. Supposing that while these conditions existed some one should discover the truth, that two times two are four, and would bring it before the world; would not the learned professor ridicule the idea and say two times two have been five since the beginning of the world, and for any one to say different is nonsense? Could you induce him to investigate?