Postwar French thought tends to agitate the English. The grandeur of its rhetoric, the ambition of its claims, the apparent imprecision of its terms and the frequent opacity of its analysis all conspire to alienate a people whose fondest native traditions are empiricism, clarity and wry self–deprecation. And what exactly are they thinking about anyway? Marx is an enduring, unhealthy obsession as was, in the Sixties, taking to the streets with gangs of murderous Maoist students. Things have not improved – look at Jacques Derrida. What’s all that about?