Paul Dirac, the great physicist, refused to accept the books that Robert Oppenheimer tried to give to him; “reading books, the Cambridge theoretician announced gravely, ‘interfered with thought’.”
The first time I heard this anecdote I was struck by its self-evident absurdity. Reading is thought. And so it is. But it’s not your thought.
I’d be the last to claim that all thought is linguistic, or verbal. Plenty of it is visual, spatial, mathematical, musical. But your internal monologue is a large part of your conscious experience. This seems especially likely for people with a facility for language — exactly the people who, like me, are in danger of reading too much.
If your experience of reading is anything like mine, then what you’re doing when you read is letting someone else write your internal monologue for you. You are not the author of your own stream of consciousness.
Now if it weren’t for reading, your consciousness would be severely limited. We all benefit from being able to think through the thoughts of Shakespeare, and a hundred or a thousand other authors besides. But there must come a point when enough is enough. We’ve only got time to think so many thoughts. Some of them should be our own.