In this study I invite you to a journey on the land of tax analysis, one that is surrounded by passion and controversies. The purpose of this “journey” is to understand the possibility that the economic science can “prescribe” the optimal taxation, both when it comes to the tax regime (progressive vs. flat tax), as well as regarding the level of taxation. I will argue the need to destroy some myths sometimes widely spread in economic theory and in the public opinion, such as the idea that flat tax is the right means against discrimination and… redistribution of wealth in society, or, on the other hand, the idea that proportional taxation is the modern source of economic prosperity. But, in order to tackle the issue of optimal taxation, we need a short historical and scientific analysis on the nature of taxation.