This is that which I think great readers are apt to be mistaken in. Those who have read of everything are thought to understand everything too; but it is not always so. Reading furnishes the mind only with materials of knowledge; it is thinking makes what we read ours. We are of the ruminating kind, and it is not enough to cram ourselves with a great load of collections; unless we chew them over again, they will not give us strength and nourishment. There are indeed in some writers visible instances of deep thoughts, close and acute reasoning, and ideas well pursued. The light these would give would be of great use if their readers would observe and imitate them; all the rest at best are but particulars fit to be turned into knowledge, but that can be done only by our own meditation, and examining the reach, force, and coherence of what is said; and then, as far as we apprehend and see the connexion of ideas, so far it is ours; without that, it is but so much loose matter floating in our brain. The memory may be stored, but the judgement is little better, and the stock of knowledge not increased, by being able to repeat what others have said or produce the arguments we have found in them. Such a knowledge as this is but knowledge by hearsay, and the ostentation of it is at best but talking by rote, and very often upon weak and wrong principles. For all that is to be found in books is not built upon true foundations, nor always rightly deduced from the principles it is pretended to be built on. Such an examination as is requisite to discover that, every reader's mind is not forward to make; especially in those who have given themselves up to a party, and only hunt for what they can scrape together that may favour and support the tenets of it. Such men wilfully exclude themselves from truth and from all true benefit to be received by reading. Others of more indifference often want attention and industry. The mind is backward in itself to be at the pains to trace every argument to its original, and to see upon what basis it stands, and how firmly; but yet it is this that gives so much the advantage to one man more than another in reading. The mind should, by severe rules, be tied down to this at first uneasy task; use and exercise will give it facility. So that those who are accustomed to it, readily, as it were with one cast of the eye, take a view of the argument, and presently, in most cases, see where it bottoms. Those who have got this faculty, one may say, have got the true key of books, and the clue to lead them through the maze of variety of opinions and authors to truth and certainty. This, young beginners should be entered in, and showed the use of, that they might profit by their reading. Those who are strangers to it will be apt to think it too great a clog in the way of men's studies, and they will suspect they shall make but small progress, if, in the books they read, they must stand to examine and unravel every argument and follow it step by step up to its original.
I answer, this is a good objection, and ought to weigh with those whose reading is designed for much talk and little knowledge, and I have nothing to say to it. But I am here inquiring into the conduct of the understanding in its progress towards knowledge; and to those who aim at that, I may say that he, who fair and softly goes steadily forward in a course that points right, will sooner be at his journey's end, than he that runs after every one he meets, though he gallop all day full speed.
To which let me add, that this way of thinking on and profiting by what we read will be a clog and rub to any one only in the beginning; when custom and exercise has made it familiar, it will be dispatched in most occasions, without resting or interruption in the course of our reading. The motions and views of a mind exercised that way are wonderfully quick; and a man, used to such sort of reflections, sees as much at one glimpse as would require a long discourse to lay before another and make out in an entire and gradual deduction. Besides, that when the first difficulties are over, the delight and sensible advantage it brings mightily encourages and enlivens the mind in reading, which without this is very improperly called study.