Derrida appearing in London yesterday and the Financial Times wrote a
story.
For Derrida, language is a network of differences; the meaning of a word entails understanding what it does not mean.
That's what Saussure wrote about signifiers in his
Course on General Linguistics, acknowledged by Derrida. The signifier is a purely relational unit and in language there are only differences, without positive terms.
Deconstruction - the method that made him famous - attempts to expose these differences in order to subvert established ways of thinking.
This isn't half bad, noting that deconstruction is a method, something that is done, although the "in order to subvert" is a bit strong. The intent is to dig deeper, and not necesssarily to be subversive. It's about reading the text outside of the box of the traditional metaphysical "ways of thinking."