I am studying early Christianity here, reading Renan and the Bible. Renan is terribly shallow but, as a man of the world, has a wider view than the German University theologians. Otherwise, his book is a novel, to which his comment on Philostratus can equally be applied: one can use it as an historical source just as one would use, say, the novels of Alexandre Dumas p re on the Fronde period. On individual points I have caught him out in dreadful mistakes. Moreover he cribs from the Germans with unbounded impudence.
Letters: Marx-Engels Correspondence 1892