He was, I learned, Derrida’s first PhD student but is in no sense now a Derridian. Part of the reason for that was that the great man let him write a substantial Derridian thesis in the way an impressed young man might. Derrida himself then did Castel the honour of giving a presentation in which he carefully, painstakingly and seriously deconstructed his text (“He did to me what he did to Husserl in Of Grammatology”). This both critically undercut the text but at the same time validated it. The next day, PHC telephoned Derrida to ask for a copy of the presentation. “Ah, Pierre-Henri! I’ve just deleted it!”. And that was that. Castel could go his own way.