Isaiah Berlin was a past-master of the genre. Here he is writing¹ to Marion and Felix Frankfurter in December 1934 about Richard Crossman, who was then a Fellow of New College, Oxford (where Berlin had been briefly a Fellow), and whom I think Berlin detested.

“Crossman is trying to sell his soul again & finding no buyers even among those who think he had one.”

I worked for Crossman briefly, when he was Editor of the New Statesman. He was an interesting man, but not a nice one.