Forming the Habit of Reading
Any art or skill is possessed by those who have formed the habit of operating according to its rules. This is the way the artist or craftsman in any field differs from those who lack his skill.
Now there is no other way of forming a habit of operation than operating. That is what it means to say one learns to do by doing. The difference between your activity before and after you have formed a habit is a difference in facility and readiness. After practice, you can do the same thing much better than when you started. That is what it means to say practice makes perfect. What you do very imperfectly at first, you gradually come to do with the kind of almost automatic perfection that an instinctive performance has. You do something as if you were born to it, as if the activity were as natural to you as walking or eating. that is what it means to say that habit is second nature.
Knowing the rules of an art is not the same as having the habit. When we speak of a man as skilled in any way, we do not mean that he knows the rules of making or doing something, but tha the possesses the habit of making or doing it. Of course, it is true that knowing the rules, more or less explicitly, is a condition of getting the skill. You cannot follow rules you do not know. Nor can you acquire an artistic habit--any craft or skill--without following rules. The art as something that can be taught consists of rules to be followed in operation. The art as something learned and possessed consists of the habit the results from operating according to the rules.
Source: J. Adler , Mortimer, and Charles Van Doren. How to Read a Book. New York: Touchstone, 1972.