Whatever may be its indetermination, be it that of "it is necessary [that there be] the future", there is some future and some history, there is perhaps even the beginning of historicity for post-historical Man, beyond man and beyond history such as they have been represented up until now. We must insist on this specific point precisely because it points to an essential lack of specificity, an indetermination that remains the ultimate mark of the future: whatever may be the case concerning the modality or the content of this duty, this necessity, this prescription or this injunction, this pledge, this task, also therefore this promise, this necessary promise, this "it is necessary" is necessary, and that is the law.

Jacques Derrida, Specters of Marx (Routledge, 1994) pp. 91-92