In our end is our beginning
Kierkegaard identified the Socratic purpose as an ironic undermining of knowledge, but an irony with an acidic edge, as it undermines all knowledge, including the knowledge of the position of the ironist. A solvent that dissolves all, in other words, leaving no solution (I'm sure I'm mixing chemical metaphors and rather than producing a crystalline cleverness rendering only the kind of sludge my home chemistry experiments used to produce. So it goes.).
Socratic irony: Socrates is the source (admittedly through Plato, but without Plato we don't have Socrates) of Western metaphysics.
Derrida worked somewhat like Socrates. He sought to undermine certainty by deconstructing it, forcing the contradictions inherent in reason (and especially in rhetoric) to the surface, to expose the limitations in what we thinks we discuss. Both philosophers working that area of epistemology best identified by the Firesign Theater: "Everything you know is wrong."
And yet Derrida ends as a philosopher of religion trying to construct a negative atheology.
Forster was right: only connect.