John Banville at The Guardian:
In a coolly furious essay published in book form in 1968, Hugh Trevor-Roper singled out Kim Philby’s “truly extraordinary egotism and complacency” as forces that seemed to the historian “to have dominated Philby’s character and determined his lonely and difficult course”. Trevor-Roper knew whereof he spoke, for he had served with the British Secret Intelligence Service during the war and saw much of Philby during those years. His observations on his former friend are shrewd. Only a man who believed in himself utterly could have given himself utterly to a cause, as Philby did.
Yet he was no fanatic; anything but. John le Carré – who, incidentally, Trevor-Roper strongly attacks in his Philby monograph – pointed out that in the depths of the “fanatic heart” there lurks a doubt, and doubt, in such a heart, is a fatal weakness.