[Sidenote: _Unwholesome Literature_] One of the chief causes of mental inefficiency and moral weakness is the lack of concentration for worthy ends. We pride ourselves on the wide distribution of literature; but the multiplication of books, even books that in themselves are not harmful, may be a positive evil. With the immense tide of printed matter constantly pouring from the press, old and young form the habit of reading hastily and superficially, and the mind loses its power of connected and vigorous thought. Furthermore, a large share of the periodicals and books that, like the frogs of Egypt, are overspreading the land, are not merely commonplace, idle, and enervating, but unclean and degrading. Their effect is not merely to intoxicate and ruin the mind, but to corrupt and destroy the soul. The mind, the heart, that is indolent, aimless, falls an easy prey to evil. It is on diseased, lifeless organisms that fungus roots. It is the idle mind that is Satan’s workshop. Let the mind be directed to high and holy ideals, let the life have a noble aim, an absorbing purpose, and evil finds little foothold. [Sidenote: _A Shield from Temptation_] Let the youth, then, be taught to give close study to the word of God. Received into the soul, it will prove a mighty barricade against temptation. “Thy word,” the psalmist declares, “have I hid in mine heart, that I might not sin against Thee.” “By the word of Thy lips I have kept me from the paths of the destroyer.”[314] [Sidenote: _Comprehensive Study_] The Bible is its own expositor. Scripture is to be compared with scripture. The student should learn to view the word as a whole, and to see the relation of its parts. He should gain a knowledge of its grand central theme, of God’s original purpose for the world, of the rise of the great controversy, and of the work of redemption. He should understand the nature of the two principles that are contending for supremacy, and should learn to trace their working through the records of history and prophecy, to the great consummation. He should see how this controversy enters into every phase of human experience; how in every act of life he himself reveals the one or the other of the two antagonistic motives; and how, whether he will or not, he is even now deciding upon which side of the controversy he will be found. Every part of the Bible is given by inspiration of God, and is profitable. The Old Testament no less than the New should receive attention. As we study the Old Testament, we shall find living springs bubbling up where the careless reader discerns only a desert. [Sidenote: _Daniel and the Revelation_]