"“I was thinking,” Harrison explained. “I approve of that,” put in His Excellency. He lugged a couple of huge tomes our of the wall-shelves, began to thumb rapidly through them. “Do plenty of thinking whenever you’ve the chance and it will become a habit. It will get easier and easier as time rolls on. In fact, a day may come when it can be done without pain.”"
January 1, 1970
https://en.wikiquote.org/wiki/Eric_Frank_Russell