Philosophy is often misunderstood. One of my friends told me that he had thought to do philosophy is to be deep in thought. But philosophy is more active. To me, doing philosophy includes reading a large number of books and articles on your research topic, making sense of them, finding a problem in them, and trying to find a solution for it. I mean to say not only that once you are engaged in it, you will find this brain work is mentally active, but also that this is physically active. You have to search for the book or the article you want to read, go to a bookstore or a library to get it, and after a few hours of reading it, rest your back and neck in order to relieve them of muscle strain. However, there is a sense in which philosophy is not active. Too many insights have been reached in a quiet moment in bed to deny this. The title of this article is an aphorism of a French philosopher, Blaise Pascal. It is said he wrote it while he was ill in bed. It can be translated this way: "All the unhappiness of the human beings comes from one single thing: that is, the inability to stay at rest in a room." Personally, I love this saying. It is one of the greatest joys in studying philosophy to find such an aphorism as is to your liking, and philosophers often come up with it at rest.