It is not the reading of many books which is necessary to make a man wise or good, but the well-reading of a few, could he be sure to have the best. And it is not possible to read over many on the same subject without a great deal of loss of precious time.
Learn to be good readers, which is perhaps a more difficult thing than you imagine. Learn to be discriminative in your reading; to read faithfully, and with your best attention, all kinds of things which you have a real interest in,–a real, not an imaginary,–and which you find to be really fit for what you are engaged in.
The first class of readers may be compared to an hour-glass, their reading being as the sand; it runs in and runs out, and leaves not a vestige behind. A second class resembles a sponge, which imbibes everything, and returns it in nearly the same state, only a little dirtier. A third class is like a jelly-bag, which allows all that is pure to pass away, and retains only the refuse and dregs. The fourth class may be compared to the slave of Golconda, who, casting aside all that is worthless, preserves only the pure gems.
–Samuel Taylor Coleridge
Philippians 4:8 (KJV) Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.