This chapter presents an introduction to an observation in science, followed by a thought experiment. It is followed by a short discussion and then a series of questions. The chapter gives a fact that science relies upon observation. It explains it with the Newton's observation of apple falling from a tree. The chapter also presents a thought experiments with a case where a person named Cecile is asked to take part in an experiment. She is shown a series of playing cards, for a very short period of time and told her to identify the cards. The questions are intended to get the philosophy students thinking about the problems. They have used these kinds of questions in seminars as the questions set for seminars, so they also think that they can be used to spark conversation and discussion. The chapter also gives a cursory sketch of some of the ways in which philosophers have responded to the thought experiment.