It seems to me that Dickens wanted to imply that Darnay and Carton were the two sons of twin brothers Evremonde. What other reason would there be for Dickens describing that Darnay and Carton look so much alike, and also that Charles Darnay's father was an identical twin?? I haven't heard anyone bring this up, but I've only done a quick searching online, and at Cliff and Sparks notes. Has this ever been looked at and does anyone know where I could go to see other writing on this subject? Also, it is said that Carton is a Christ figure, but he is beheaded like John the Baptist. To continue this comparison of Carton to John the Baptist, Carton feels unworthy in comparison to his friend Darnay, just as John the Baptist tells everyone that he is not even worthy to tie the straps on the sandals of One who is to come (Jesus). Also, aren't John the Baptist and Jesus cousins? Then it all fits. Darnay and Carton are cousins too in my opinion.