I attended the New Kind of Church Conference in London last year and also brought up the issue of hermeneutics and the idea (Derrida’s) that justice can not be deconstructed. His understanding of justice has changed slightly (a subject I’m beginning to try to trace as I’d like to do some postgrad study in this in a couple of years time) however the quote you need on justice being ‘undeconstructible’ should be found in:
‘Force of Law: “The Mystical foundation of Authority”’, trans. Mary Quaintance, Cardozo Law Review, 11: 5/6 (1990), 945.
‘I Have a Taste for the Secret’, Jacques Derrida in conversation with Maurizio Ferraris and Giorgio Vattimo, in Derrida and Ferraris, A Taste for Secret, trans. Giacomo Donis (Cambridge, UK: Polity, 2001), 56.
For a good introduction to Derrida (generally and including his development of justice) try: Royle, Nicholas. Jaques Derrida, (London: Routledge, 2003).
To be honest I haven’t read these quotes in context yet (only referenced in other scholarly works) as in an effort to immerse myself in his thought patterns I’m starting from some of his earlier works and will try to trace the evolution of his thoughts. This is because despite interacting with deconstruction & other poststructuralist methods of interpretation I’ve really only seen them in the context of biblical studies (MA research) and for my intended research I want to interact with Derrida’s work (and his ideas of justice and religion) directly.
Thanks so much for this help. You sound like just the kind of thoughtful scholar that we need many more of!