In this thesis I defend the principle of global egalitarianism. According to this idea most of the existing detrimental inequalities in this world are morally objectionable. As detrimental inequalities I understand those that are not to the benefit of the worst off people and that can be non-wastefully removed. To begin with, I consider various justifications of the idea that only those detrimental inequalities that occur within one and the same state are morally objectionable. I identify Thomas Nagel’s approach as the most promising defence of this traditional position. However, I also show that Nagel’s argument does not even justify the elimination of detrimental inequalities (that is to say: egalitarian duties of justice) within...