“How is it,” our Lord asked of the lawyers, “that ye do not discern this time?” Those men, who were the accredited expounders of Scripture, had, it appears, given enough attention to natural phenomena to be able to predict heat or rain a little way in advance, but they were stone blind to the signs by which the Son of God was making known the tremendous fact of his presence among men! We have developed their simple, elementary study of Nature into a vast science, Physics.