This chapter deals with the question whether economics is a science, or not? Most economists presented in this chapter respond that economics is partly ideological in content but also partly scientific. As Joan Robinson observed, economics is partly a vehicle for the ruling ideology and partly a method of scientific investigation. Scarcity shines through in most definitions of the subject. According to Lionel Robbins, economics is the science which studies human behaviour as a relationship between ends and scarce means which have alternative uses. The relationship between philosophy and economics and how it evolved is also presented. A cross-fertilization between them is taking place. Liberalism greatly influenced economists from Adam Smith onwards. Not all great economists took positive inspiration from liberalism; some of them were not so positive about it. The economists presented in this book are all game-changers, as they did not just change the way economics can be perceived, they also presented proposals to achieve a more prosperous, just, and equitable world.