This is term with which Derrida introduces an opening for the coming of the future, or its arrival. Because one can never know what will happened, even a few seconds from now, undecidability becomes a constitutive element of the future’s arrival. Undecidability must not be read as the antithesis of decision making. “On the contrary”, Martin Hagglund says in Radical Atheism: Derrida and the Time of Life, “it is because the future cannot be decided in advance that one needs to make decisions” (40, emphasis in original).
Realism 