In its first and most famous instantiation, undecidability is one of
Derrida’s most important attempts to trouble dualisms, or more
accurately, to reveal how they are always already troubled. An
undecidable, and there are many of them in deconstruction (eg. ghost,
pharmakon, hymen, etc.), is something that cannot conform to either
polarity of a dichotomy (eg. present/absent, cure/poison, and
inside/outside in the above examples). For example, the figure of a
ghost seems to neither present or absent, or alternatively it is both
present and absent at the same time (SM).
However, Derrida has a recurring tendency to resuscitate terms in different contexts, and the term undecidability also returns in later deconstruction. Indeed, to complicate matters, undecidability returns in two discernible forms. In his recent work, Derrida often insists that the condition of the possibility of mourning, giving, forgiving, and hospitality, to cite some of his most famous examples, is at once also the condition of their impossibility (see section 7). In his explorations of these “possible-impossible” aporias, it becomes undecidable whether genuine giving, for example, is either a possible or an impossible ideal.
However, Derrida has a recurring tendency to resuscitate terms in different contexts, and the term undecidability also returns in later deconstruction. Indeed, to complicate matters, undecidability returns in two discernible forms. In his recent work, Derrida often insists that the condition of the possibility of mourning, giving, forgiving, and hospitality, to cite some of his most famous examples, is at once also the condition of their impossibility (see section 7). In his explorations of these “possible-impossible” aporias, it becomes undecidable whether genuine giving, for example, is either a possible or an impossible ideal.
