Suppose I said to someone: “Observe the particular lighting of this room.” ‒ ‒ Under certain circumstances the sense of this order || imperative will be quite clear, e.g., if the walls of the room were red with the setting sun. But suppose at any other time when there is nothing striking about the lighting I said, “Observe the particular lighting of this room”: – – Well, isn't there a particular lighting? So what is the difficulty about observing it? But the person who was told to observe the lighting when there was nothing striking about it would probably look about the room and say, “Well, what about it?” Now I might go on and say, “It is exactly the same lighting as yesterday at this hour”, or “It is just this slightly dim light which you see in this picture of the room.”