Twenty years ago the Scottish dogmatic theologian T. F. Torrance read a paper in Cambridge setting out the whole gospel of the dogmatist. In the discussion that followed I asked him how he accounted for the widespread and intractable disagreements that plague theology. 'Sin,' he answered shortly (and doubtless with people like me in mind), and that was that.
Later Cupitt deals to Barth as well, writing of "the followers of Karl Barth, who are the last remaining people who still think of attempting systematic theology." How true.