In this paper, I examine global public reason as a method of justifying a global state. Ultimately, I conclude that global public reason fails to justify a global state. This is the case, because global public reason faces an unwinnable dilemma. The global public reason theorist must endorse either a hypothetical theory of consent or an actual theory of consent; if she endorses a theory of hypothetical consent, then she fails to justify her principles; and if she endorses a theory (...) of actual consent, her theory will lead to a highly unstable political system. On either side of the dilemma, global public reason faces untenable implications. Although similar criticisms have been advanced against domestic public reason, my argument is not repeating points made before me. My argument is new, in that it raises these objections specifically against global public reason, and in that it shows how, due to increased diversity of belief in the global arena, these problems are more pressing for global public reason than they are for domestic public reason. (shrink)