1. An ideological field? Believing in an absolute idea or defending an ideology is the best way to lose—more or less permanently—all objectivity. The book Arbitrating the Conduct of International Investors by Amado, Kern and Doe (the Book) reminds us from its first pages of the fact that investment arbitration has often been criticized from an ideologically tainted and, hence, subjective standpoint. One can indeed read today more manifestos about investment arbitration than objective, juridical analyses of it. It is worth mentioning two of those ideologies: the ideology of sovereignty and the ideology of efficiency. 2. The ideology of sovereignty. For some, investment arbitration lacks legitimacy because the State’s sovereignty should not be limited by the decisions made by three private persons called arbitrators. How, they ask, could three private persons judge upon the soundness of, for example, the State’s newly enacted legislation on sensitive matters, such as public health or the environment? They regularly add that those arbitrators in most cases do not know and, hence, misunderstand the cultural particularities of developing States hosting investments (host State). How, they argue, could a European arbitrator understand the political history and idiosyncratic issues of some Latin American and African States? The train is not always on time in all countries. Because of their sovereignty, developing States, they say, should have the right to behave differently from developed States in, for instance, the preservation of their instable economies. Do they?