The spectre is something that is not present, not real, not there, but that nonetheless enters into (and disrupts the closure and self-presence of) whatever is present, real, and there. The ghost addresses us, interrogates us with its voice and its gaze; it’s a call from Otherness to which we must respond, even though we are unable to adequately respond.
We cannot ever simply separate the relevant from the irrelevant, or the living from the dead. The uncanny apparition of the spectre forbids us to make so neat a separation. We are always haunted by ghosts, and we cannot freely choose what we will be haunted by. We have the responsibility of making such a separation, without the ability neatly and definitively to do so.